


PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


NAME
       perlapi - autogenerated documentation for the perl public
       API

DESCRIPTION
       This file contains the documentation of the perl public
       API generated by embed.pl, specifically a listing of
       functions, macros, flags, and variables that may be used
       by extension writers.  The interfaces of any functions
       that are not listed here are subject to change without
       notice.  For this reason, blindly using functions listed
       in proto.h is to be avoided when writing extensions.

       Note that all Perl API global variables must be referenced
       with the "PL_" prefix.  Some macros are provided for
       compatibility with the older, unadorned names, but this
       support may be disabled in a future release.

       Perl was originally written to handle US-ASCII only (that
       is characters whose ordinal numbers are in the range 0 -
       127).  And documentation and comments may still use the
       term ASCII, when sometimes in fact the entire range from 0
       - 255 is meant.

       Note that Perl can be compiled and run under EBCDIC (See
       perlebcdic) or ASCII.  Most of the documentation (and even
       comments in the code) ignore the EBCDIC possibility.  For
       almost all purposes the differences are transparent.  As
       an example, under EBCDIC, instead of UTF-8, UTF-EBCDIC is
       used to encode Unicode strings, and so whenever this
       documentation refers to "utf8" (and variants of that name,
       including in function names), it also (essentially
       transparently) means "UTF-EBCDIC".  But the ordinals of
       characters differ between ASCII, EBCDIC, and the UTF-
       encodings, and a string encoded in UTF-EBCDIC may occupy
       more bytes than in UTF-8.

       Also, on some EBCDIC machines, functions that are
       documented as operating on US-ASCII (or Basic Latin in
       Unicode terminology) may in fact operate on all 256
       characters in the EBCDIC range, not just the subset
       corresponding to US-ASCII.

       The listing below is alphabetical, case insensitive.

"Gimme" Values
       GIMME   A backward-compatible version of "GIMME_V" which
               can only return "G_SCALAR" or "G_ARRAY"; in a void
               context, it returns "G_SCALAR".  Deprecated.  Use
               "GIMME_V" instead.

                       U32     GIMME

       GIMME_V The XSUB-writer's equivalent to Perl's



perl v5.10.1                2010-03-17                          1





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "wantarray".  Returns "G_VOID", "G_SCALAR" or
               "G_ARRAY" for void, scalar or list context,
               respectively.

                       U32     GIMME_V

       G_ARRAY Used to indicate list context.  See "GIMME_V",
               "GIMME" and perlcall.

       G_DISCARD
               Indicates that arguments returned from a callback
               should be discarded.  See perlcall.

       G_EVAL  Used to force a Perl "eval" wrapper around a
               callback.  See perlcall.

       G_NOARGS
               Indicates that no arguments are being sent to a
               callback.  See perlcall.

       G_SCALAR
               Used to indicate scalar context.  See "GIMME_V",
               "GIMME", and perlcall.

       G_VOID  Used to indicate void context.  See "GIMME_V" and
               perlcall.

Array Manipulation Functions
       AvFILL  Same as "av_len()".  Deprecated, use "av_len()"
               instead.

                       int     AvFILL(AV* av)

       av_clear
               Clears an array, making it empty.  Does not free
               the memory used by the array itself.

                       void    av_clear(AV *av)

       av_create_and_push
               Push an SV onto the end of the array, creating the
               array if necessary.  A small internal helper
               function to remove a commonly duplicated idiom.

               NOTE: this function is experimental and may change
               or be removed without notice.

                       void    av_create_and_push(AV **const avp, SV *const val)

       av_create_and_unshift_one
               Unshifts an SV onto the beginning of the array,
               creating the array if necessary.  A small internal
               helper function to remove a commonly duplicated
               idiom.



perl v5.10.1                2010-03-17                          2





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               NOTE: this function is experimental and may change
               or be removed without notice.

                       SV**    av_create_and_unshift_one(AV **const avp, SV *const val)

       av_delete
               Deletes the element indexed by "key" from the
               array.  Returns the deleted element. If "flags"
               equals "G_DISCARD", the element is freed and null
               is returned.

                       SV*     av_delete(AV *av, I32 key, I32 flags)

       av_exists
               Returns true if the element indexed by "key" has
               been initialized.

               This relies on the fact that uninitialized array
               elements are set to &PL_sv_undef.

                       bool    av_exists(AV *av, I32 key)

       av_extend
               Pre-extend an array.  The "key" is the index to
               which the array should be extended.

                       void    av_extend(AV *av, I32 key)

       av_fetch
               Returns the SV at the specified index in the
               array.  The "key" is the index.  If "lval" is set
               then the fetch will be part of a store.  Check
               that the return value is non-null before
               dereferencing it to a "SV*".

               See "Understanding the Magic of Tied Hashes and
               Arrays" in perlguts for more information on how to
               use this function on tied arrays.

                       SV**    av_fetch(AV *av, I32 key, I32 lval)

       av_fill Set the highest index in the array to the given
               number, equivalent to Perl's "$#array = $fill;".

               The number of elements in the an array will be
               "fill + 1" after av_fill() returns.  If the array
               was previously shorter then the additional
               elements appended are set to "PL_sv_undef".  If
               the array was longer, then the excess elements are
               freed.  "av_fill(av, -1)" is the same as
               "av_clear(av)".

                       void    av_fill(AV *av, I32 fill)




perl v5.10.1                2010-03-17                          3





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       av_len  Returns the highest index in the array.  The
               number of elements in the array is "av_len(av) +
               1".  Returns -1 if the array is empty.

                       I32     av_len(const AV *av)

       av_make Creates a new AV and populates it with a list of
               SVs.  The SVs are copied into the array, so they
               may be freed after the call to av_make.  The new
               AV will have a reference count of 1.

                       AV*     av_make(I32 size, SV **strp)

       av_pop  Pops an SV off the end of the array.  Returns
               &PL_sv_undef if the array is empty.

                       SV*     av_pop(AV *av)

       av_push Pushes an SV onto the end of the array.  The array
               will grow automatically to accommodate the
               addition. Like "av_store", this takes ownership of
               one reference count.

                       void    av_push(AV *av, SV *val)

       av_shift
               Shifts an SV off the beginning of the array.
               Returns &PL_sv_undef if the array is empty.

                       SV*     av_shift(AV *av)

       av_store
               Stores an SV in an array.  The array index is
               specified as "key".  The return value will be NULL
               if the operation failed or if the value did not
               need to be actually stored within the array (as in
               the case of tied arrays). Otherwise it can be
               dereferenced to get the original "SV*".  Note that
               the caller is responsible for suitably
               incrementing the reference count of "val" before
               the call, and decrementing it if the function
               returned NULL.

               See "Understanding the Magic of Tied Hashes and
               Arrays" in perlguts for more information on how to
               use this function on tied arrays.

                       SV**    av_store(AV *av, I32 key, SV *val)

       av_undef
               Undefines the array.  Frees the memory used by the
               array itself.

                       void    av_undef(AV *av)



perl v5.10.1                2010-03-17                          4





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       av_unshift
               Unshift the given number of "undef" values onto
               the beginning of the array.  The array will grow
               automatically to accommodate the addition.  You
               must then use "av_store" to assign values to these
               new elements.

                       void    av_unshift(AV *av, I32 num)

       get_av  Returns the AV of the specified Perl array.
               "flags" are passed to "gv_fetchpv". If "GV_ADD" is
               set and the Perl variable does not exist then it
               will be created.  If "flags" is zero and the
               variable does not exist then NULL is returned.

               NOTE: the perl_ form of this function is
               deprecated.

                       AV*     get_av(const char *name, I32 flags)

       newAV   Creates a new AV.  The reference count is set to
               1.

                       AV*     newAV()

       sortsv  Sort an array. Here is an example:

                   sortsv(AvARRAY(av), av_len(av)+1, Perl_sv_cmp_locale);

               Currently this always uses mergesort. See
               sortsv_flags for a more flexible routine.

                       void    sortsv(SV** array, size_t num_elts, SVCOMPARE_t cmp)

       sortsv_flags
               Sort an array, with various options.

                       void    sortsv_flags(SV** array, size_t num_elts, SVCOMPARE_t cmp, U32 flags)

Callback Functions
       call_argv
               Performs a callback to the specified Perl sub.
               See perlcall.

               NOTE: the perl_ form of this function is
               deprecated.

                       I32     call_argv(const char* sub_name, I32 flags, char** argv)

       call_method
               Performs a callback to the specified Perl method.
               The blessed object must be on the stack.  See
               perlcall.




perl v5.10.1                2010-03-17                          5





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               NOTE: the perl_ form of this function is
               deprecated.

                       I32     call_method(const char* methname, I32 flags)

       call_pv Performs a callback to the specified Perl sub.
               See perlcall.

               NOTE: the perl_ form of this function is
               deprecated.

                       I32     call_pv(const char* sub_name, I32 flags)

       call_sv Performs a callback to the Perl sub whose name is
               in the SV.  See perlcall.

               NOTE: the perl_ form of this function is
               deprecated.

                       I32     call_sv(SV* sv, VOL I32 flags)

       ENTER   Opening bracket on a callback.  See "LEAVE" and
               perlcall.

                               ENTER;

       eval_pv Tells Perl to "eval" the given string and return
               an SV* result.

               NOTE: the perl_ form of this function is
               deprecated.

                       SV*     eval_pv(const char* p, I32 croak_on_error)

       eval_sv Tells Perl to "eval" the string in the SV.

               NOTE: the perl_ form of this function is
               deprecated.

                       I32     eval_sv(SV* sv, I32 flags)

       FREETMPS
               Closing bracket for temporaries on a callback.
               See "SAVETMPS" and perlcall.

                               FREETMPS;

       LEAVE   Closing bracket on a callback.  See "ENTER" and
               perlcall.

                               LEAVE;

       SAVETMPS
               Opening bracket for temporaries on a callback.



perl v5.10.1                2010-03-17                          6





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               See "FREETMPS" and perlcall.

                               SAVETMPS;

Character classes
       isALNUM Returns a boolean indicating whether the C "char"
               is a US-ASCII (Basic Latin) alphanumeric character
               (including underscore) or digit.

                       bool    isALNUM(char ch)

       isALPHA Returns a boolean indicating whether the C "char"
               is a US-ASCII (Basic Latin) alphabetic character.

                       bool    isALPHA(char ch)

       isDIGIT Returns a boolean indicating whether the C "char"
               is a US-ASCII (Basic Latin) digit.

                       bool    isDIGIT(char ch)

       isLOWER Returns a boolean indicating whether the C "char"
               is a US-ASCII (Basic Latin) lowercase character.

                       bool    isLOWER(char ch)

       isSPACE Returns a boolean indicating whether the C "char"
               is a US-ASCII (Basic Latin) whitespace.

                       bool    isSPACE(char ch)

       isUPPER Returns a boolean indicating whether the C "char"
               is a US-ASCII (Basic Latin) uppercase character.

                       bool    isUPPER(char ch)

       toLOWER Converts the specified character to lowercase.
               Characters outside the US-ASCII (Basic Latin)
               range are viewed as not having any case.

                       char    toLOWER(char ch)

       toUPPER Converts the specified character to uppercase.
               Characters outside the US-ASCII (Basic Latin)
               range are viewed as not having any case.

                       char    toUPPER(char ch)

Cloning an interpreter
       perl_clone
               Create and return a new interpreter by cloning the
               current one.

               perl_clone takes these flags as parameters:



perl v5.10.1                2010-03-17                          7





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               CLONEf_COPY_STACKS - is used to, well, copy the
               stacks also, without it we only clone the data and
               zero the stacks, with it we copy the stacks and
               the new perl interpreter is ready to run at the
               exact same point as the previous one.  The pseudo-
               fork code uses COPY_STACKS while the
               threads->create doesn't.

               CLONEf_KEEP_PTR_TABLE perl_clone keeps a ptr_table
               with the pointer of the old variable as a key and
               the new variable as a value, this allows it to
               check if something has been cloned and not clone
               it again but rather just use the value and
               increase the refcount. If KEEP_PTR_TABLE is not
               set then perl_clone will kill the ptr_table using
               the function "ptr_table_free(PL_ptr_table);
               PL_ptr_table = NULL;", reason to keep it around is
               if you want to dup some of your own variable who
               are outside the graph perl scans, example of this
               code is in threads.xs create

               CLONEf_CLONE_HOST This is a win32 thing, it is
               ignored on unix, it tells perls win32host code
               (which is c++) to clone itself, this is needed on
               win32 if you want to run two threads at the same
               time, if you just want to do some stuff in a
               separate perl interpreter and then throw it away
               and return to the original one, you don't need to
               do anything.

                       PerlInterpreter*        perl_clone(PerlInterpreter *proto_perl, UV flags)

CV Manipulation Functions
       CvSTASH Returns the stash of the CV.

                       HV*     CvSTASH(CV* cv)

       get_cv  Uses "strlen" to get the length of "name", then
               calls "get_cvn_flags".

               NOTE: the perl_ form of this function is
               deprecated.

                       CV*     get_cv(const char* name, I32 flags)

       get_cvn_flags
               Returns the CV of the specified Perl subroutine.
               "flags" are passed to "gv_fetchpvn_flags". If
               "GV_ADD" is set and the Perl subroutine does not
               exist then it will be declared (which has the same
               effect as saying "sub name;").  If "GV_ADD" is not
               set and the subroutine does not exist then NULL is
               returned.




perl v5.10.1                2010-03-17                          8





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               NOTE: the perl_ form of this function is
               deprecated.

                       CV*     get_cvn_flags(const char* name, STRLEN len, I32 flags)

Embedding Functions
       cv_undef
               Clear out all the active components of a CV. This
               can happen either by an explicit "undef &foo", or
               by the reference count going to zero.  In the
               former case, we keep the CvOUTSIDE pointer, so
               that any anonymous children can still follow the
               full lexical scope chain.

                       void    cv_undef(CV* cv)

       load_module
               Loads the module whose name is pointed to by the
               string part of name.  Note that the actual module
               name, not its filename, should be given.  Eg,
               "Foo::Bar" instead of "Foo/Bar.pm".  flags can be
               any of PERL_LOADMOD_DENY, PERL_LOADMOD_NOIMPORT,
               or PERL_LOADMOD_IMPORT_OPS (or 0 for no flags).
               ver, if specified, provides version semantics
               similar to "use Foo::Bar VERSION".  The optional
               trailing SV* arguments can be used to specify
               arguments to the module's import() method, similar
               to "use Foo::Bar VERSION LIST".  They must be
               terminated with a final NULL pointer.  Note that
               this list can only be omitted when the
               PERL_LOADMOD_NOIMPORT flag has been used.
               Otherwise at least a single NULL pointer to
               designate the default import list is required.

                       void    load_module(U32 flags, SV* name, SV* ver, ...)

       nothreadhook
               Stub that provides thread hook for perl_destruct
               when there are no threads.

                       int     nothreadhook()

       perl_alloc
               Allocates a new Perl interpreter.  See perlembed.

                       PerlInterpreter*        perl_alloc()

       perl_construct
               Initializes a new Perl interpreter.  See
               perlembed.

                       void    perl_construct(PerlInterpreter *my_perl)





perl v5.10.1                2010-03-17                          9





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       perl_destruct
               Shuts down a Perl interpreter.  See perlembed.

                       int     perl_destruct(PerlInterpreter *my_perl)

       perl_free
               Releases a Perl interpreter.  See perlembed.

                       void    perl_free(PerlInterpreter *my_perl)

       perl_parse
               Tells a Perl interpreter to parse a Perl script.
               See perlembed.

                       int     perl_parse(PerlInterpreter *my_perl, XSINIT_t xsinit, int argc, char** argv, char** env)

       perl_run
               Tells a Perl interpreter to run.  See perlembed.

                       int     perl_run(PerlInterpreter *my_perl)

       require_pv
               Tells Perl to "require" the file named by the
               string argument.  It is analogous to the Perl code
               "eval "require '$file'"".  It's even implemented
               that way; consider using load_module instead.

               NOTE: the perl_ form of this function is
               deprecated.

                       void    require_pv(const char* pv)

Functions in file dump.c
       pv_display
               Similar to

                 pv_escape(dsv,pv,cur,pvlim,PERL_PV_ESCAPE_QUOTE);

               except that an additional "\0" will be appended to
               the string when len > cur and pv[cur] is "\0".

               Note that the final string may be up to 7 chars
               longer than pvlim.

                       char*   pv_display(SV *dsv, const char *pv, STRLEN cur, STRLEN len, STRLEN pvlim)

       pv_escape
               Escapes at most the first "count" chars of pv and
               puts the results into dsv such that the size of
               the escaped string will not exceed "max" chars and
               will not contain any incomplete escape sequences.

               If flags contains PERL_PV_ESCAPE_QUOTE then any
               double quotes in the string will also be escaped.



perl v5.10.1                2010-03-17                         10





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               Normally the SV will be cleared before the escaped
               string is prepared, but when
               PERL_PV_ESCAPE_NOCLEAR is set this will not occur.

               If PERL_PV_ESCAPE_UNI is set then the input string
               is treated as Unicode, if
               PERL_PV_ESCAPE_UNI_DETECT is set then the input
               string is scanned using "is_utf8_string()" to
               determine if it is Unicode.

               If PERL_PV_ESCAPE_ALL is set then all input chars
               will be output using "\x01F1" style escapes,
               otherwise only chars above 255 will be escaped
               using this style, other non printable chars will
               use octal or common escaped patterns like "\n". If
               PERL_PV_ESCAPE_NOBACKSLASH then all chars below
               255 will be treated as printable and will be
               output as literals.

               If PERL_PV_ESCAPE_FIRSTCHAR is set then only the
               first char of the string will be escaped,
               regardles of max. If the string is utf8 and the
               chars value is >255 then it will be returned as a
               plain hex sequence. Thus the output will either be
               a single char, an octal escape sequence, a special
               escape like "\n" or a 3 or more digit hex value.

               If PERL_PV_ESCAPE_RE is set then the escape char
               used will be a '%' and not a '\\'. This is because
               regexes very often contain backslashed sequences,
               whereas '%' is not a particularly common character
               in patterns.

               Returns a pointer to the escaped text as held by
               dsv.

                       char*   pv_escape(SV *dsv, char const * const str, const STRLEN count, const STRLEN max, STRLEN * const escaped, const U32 flags)

       pv_pretty
               Converts a string into something presentable,
               handling escaping via pv_escape() and supporting
               quoting and ellipses.

               If the PERL_PV_PRETTY_QUOTE flag is set then the
               result will be double quoted with any double
               quotes in the string escaped. Otherwise if the
               PERL_PV_PRETTY_LTGT flag is set then the result be
               wrapped in angle brackets.

               If the PERL_PV_PRETTY_ELLIPSES flag is set and not
               all characters in string were output then an
               ellipsis "..." will be appended to the string.
               Note that this happens AFTER it has been quoted.




perl v5.10.1                2010-03-17                         11





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               If start_color is non-null then it will be
               inserted after the opening quote (if there is one)
               but before the escaped text. If end_color is non-
               null then it will be inserted after the escaped
               text but before any quotes or ellipses.

               Returns a pointer to the prettified text as held
               by dsv.

                       char*   pv_pretty(SV *dsv, char const * const str, const STRLEN count, const STRLEN max, char const * const start_color, char const * const end_color, const U32 flags)

Functions in file mathoms.c
       gv_fetchmethod
               See gv_fetchmethod_autoload.

                       GV*     gv_fetchmethod(HV* stash, const char* name)

       pack_cat
               The engine implementing pack() Perl function.
               Note: parameters next_in_list and flags are not
               used. This call should not be used; use packlist
               instead.

                       void    pack_cat(SV *cat, const char *pat, const char *patend, SV **beglist, SV **endlist, SV ***next_in_list, U32 flags)

       sv_2pvbyte_nolen
               Return a pointer to the byte-encoded
               representation of the SV.  May cause the SV to be
               downgraded from UTF-8 as a side-effect.

               Usually accessed via the "SvPVbyte_nolen" macro.

                       char*   sv_2pvbyte_nolen(SV* sv)

       sv_2pvutf8_nolen
               Return a pointer to the UTF-8-encoded
               representation of the SV.  May cause the SV to be
               upgraded to UTF-8 as a side-effect.

               Usually accessed via the "SvPVutf8_nolen" macro.

                       char*   sv_2pvutf8_nolen(SV* sv)

       sv_2pv_nolen
               Like "sv_2pv()", but doesn't return the length
               too. You should usually use the macro wrapper
               "SvPV_nolen(sv)" instead.
                    char*     sv_2pv_nolen(SV* sv)

       sv_catpvn_mg
               Like "sv_catpvn", but also handles 'set' magic.

                       void    sv_catpvn_mg(SV *sv, const char *ptr, STRLEN len)




perl v5.10.1                2010-03-17                         12





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_catsv_mg
               Like "sv_catsv", but also handles 'set' magic.

                       void    sv_catsv_mg(SV *dsv, SV *ssv)

       sv_force_normal
               Undo various types of fakery on an SV: if the PV
               is a shared string, make a private copy; if we're
               a ref, stop refing; if we're a glob, downgrade to
               an xpvmg. See also "sv_force_normal_flags".

                       void    sv_force_normal(SV *sv)

       sv_iv   A private implementation of the "SvIVx" macro for
               compilers which can't cope with complex macro
               expressions. Always use the macro instead.

                       IV      sv_iv(SV* sv)

       sv_nolocking
               Dummy routine which "locks" an SV when there is no
               locking module present.  Exists to avoid test for
               a NULL function pointer and because it could
               potentially warn under some level of strict-ness.

               "Superseded" by sv_nosharing().

                       void    sv_nolocking(SV *sv)

       sv_nounlocking
               Dummy routine which "unlocks" an SV when there is
               no locking module present.  Exists to avoid test
               for a NULL function pointer and because it could
               potentially warn under some level of strict-ness.

               "Superseded" by sv_nosharing().

                       void    sv_nounlocking(SV *sv)

       sv_nv   A private implementation of the "SvNVx" macro for
               compilers which can't cope with complex macro
               expressions. Always use the macro instead.

                       NV      sv_nv(SV* sv)

       sv_pv   Use the "SvPV_nolen" macro instead

                       char*   sv_pv(SV *sv)

       sv_pvbyte
               Use "SvPVbyte_nolen" instead.

                       char*   sv_pvbyte(SV *sv)




perl v5.10.1                2010-03-17                         13





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_pvbyten
               A private implementation of the "SvPVbyte" macro
               for compilers which can't cope with complex macro
               expressions. Always use the macro instead.

                       char*   sv_pvbyten(SV *sv, STRLEN *lp)

       sv_pvn  A private implementation of the "SvPV" macro for
               compilers which can't cope with complex macro
               expressions. Always use the macro instead.

                       char*   sv_pvn(SV *sv, STRLEN *lp)

       sv_pvutf8
               Use the "SvPVutf8_nolen" macro instead

                       char*   sv_pvutf8(SV *sv)

       sv_pvutf8n
               A private implementation of the "SvPVutf8" macro
               for compilers which can't cope with complex macro
               expressions. Always use the macro instead.

                       char*   sv_pvutf8n(SV *sv, STRLEN *lp)

       sv_taint
               Taint an SV. Use "SvTAINTED_on" instead.
                    void sv_taint(SV* sv)

       sv_unref
               Unsets the RV status of the SV, and decrements the
               reference count of whatever was being referenced
               by the RV.  This can almost be thought of as a
               reversal of "newSVrv".  This is "sv_unref_flags"
               with the "flag" being zero.  See "SvROK_off".

                       void    sv_unref(SV* sv)

       sv_usepvn
               Tells an SV to use "ptr" to find its string value.
               Implemented by calling "sv_usepvn_flags" with
               "flags" of 0, hence does not handle 'set' magic.
               See "sv_usepvn_flags".

                       void    sv_usepvn(SV* sv, char* ptr, STRLEN len)

       sv_usepvn_mg
               Like "sv_usepvn", but also handles 'set' magic.

                       void    sv_usepvn_mg(SV *sv, char *ptr, STRLEN len)

       sv_uv   A private implementation of the "SvUVx" macro for
               compilers which can't cope with complex macro
               expressions. Always use the macro instead.



perl v5.10.1                2010-03-17                         14





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       UV      sv_uv(SV* sv)

       unpack_str
               The engine implementing unpack() Perl function.
               Note: parameters strbeg, new_s and ocnt are not
               used. This call should not be used, use
               unpackstring instead.

                       I32     unpack_str(const char *pat, const char *patend, const char *s, const char *strbeg, const char *strend, char **new_s, I32 ocnt, U32 flags)

Functions in file perl.h
       PERL_SYS_INIT
               Provides system-specific tune up of the C runtime
               environment necessary to run Perl interpreters.
               This should be called only once, before creating
               any Perl interpreters.

                       void    PERL_SYS_INIT(int argc, char** argv)

       PERL_SYS_INIT3
               Provides system-specific tune up of the C runtime
               environment necessary to run Perl interpreters.
               This should be called only once, before creating
               any Perl interpreters.

                       void    PERL_SYS_INIT3(int argc, char** argv, char** env)

       PERL_SYS_TERM
               Provides system-specific clean up of the C runtime
               environment after running Perl interpreters. This
               should be called only once, after freeing any
               remaining Perl interpreters.

                       void    PERL_SYS_TERM()

Functions in file pp_ctl.c
       find_runcv
               Locate the CV corresponding to the currently
               executing sub or eval.  If db_seqp is non_null,
               skip CVs that are in the DB package and populate
               *db_seqp with the cop sequence number at the point
               that the DB:: code was entered. (allows debuggers
               to eval in the scope of the breakpoint rather than
               in the scope of the debugger itself).

                       CV*     find_runcv(U32 *db_seqp)

Functions in file pp_pack.c
       packlist
               The engine implementing pack() Perl function.

                       void    packlist(SV *cat, const char *pat, const char *patend, SV **beglist, SV **endlist)





perl v5.10.1                2010-03-17                         15





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       unpackstring
               The engine implementing unpack() Perl function.
               "unpackstring" puts the extracted list items on
               the stack and returns the number of elements.
               Issue "PUTBACK" before and "SPAGAIN" after the
               call to this function.

                       I32     unpackstring(const char *pat, const char *patend, const char *s, const char *strend, U32 flags)

GV Functions
       GvSV    Return the SV from the GV.

                       SV*     GvSV(GV* gv)

       gv_const_sv
               If "gv" is a typeglob whose subroutine entry is a
               constant sub eligible for inlining, or "gv" is a
               placeholder reference that would be promoted to
               such a typeglob, then returns the value returned
               by the sub.  Otherwise, returns NULL.

                       SV*     gv_const_sv(GV* gv)

       gv_fetchmeth
               Returns the glob with the given "name" and a
               defined subroutine or "NULL".  The glob lives in
               the given "stash", or in the stashes accessible
               via @ISA and UNIVERSAL::.

               The argument "level" should be either 0 or -1.  If
               "level==0", as a side-effect creates a glob with
               the given "name" in the given "stash" which in the
               case of success contains an alias for the
               subroutine, and sets up caching info for this
               glob.

               This function grants "SUPER" token as a postfix of
               the stash name. The GV returned from
               "gv_fetchmeth" may be a method cache entry, which
               is not visible to Perl code.  So when calling
               "call_sv", you should not use the GV directly;
               instead, you should use the method's CV, which can
               be obtained from the GV with the "GvCV" macro.

                       GV*     gv_fetchmeth(HV* stash, const char* name, STRLEN len, I32 level)

       gv_fetchmethod_autoload
               Returns the glob which contains the subroutine to
               call to invoke the method on the "stash".  In fact
               in the presence of autoloading this may be the
               glob for "AUTOLOAD".  In this case the
               corresponding variable $AUTOLOAD is already setup.

               The third parameter of "gv_fetchmethod_autoload"



perl v5.10.1                2010-03-17                         16





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               determines whether AUTOLOAD lookup is performed if
               the given method is not present: non-zero means
               yes, look for AUTOLOAD; zero means no, don't look
               for AUTOLOAD.  Calling "gv_fetchmethod" is
               equivalent to calling "gv_fetchmethod_autoload"
               with a non-zero "autoload" parameter.

               These functions grant "SUPER" token as a prefix of
               the method name. Note that if you want to keep the
               returned glob for a long time, you need to check
               for it being "AUTOLOAD", since at the later time
               the call may load a different subroutine due to
               $AUTOLOAD changing its value. Use the glob created
               via a side effect to do this.

               These functions have the same side-effects and as
               "gv_fetchmeth" with "level==0".  "name" should be
               writable if contains ':' or ' ''. The warning
               against passing the GV returned by "gv_fetchmeth"
               to "call_sv" apply equally to these functions.

                       GV*     gv_fetchmethod_autoload(HV* stash, const char* name, I32 autoload)

       gv_fetchmeth_autoload
               Same as gv_fetchmeth(), but looks for autoloaded
               subroutines too.  Returns a glob for the
               subroutine.

               For an autoloaded subroutine without a GV, will
               create a GV even if "level < 0".  For an
               autoloaded subroutine without a stub, GvCV() of
               the result may be zero.

                       GV*     gv_fetchmeth_autoload(HV* stash, const char* name, STRLEN len, I32 level)

       gv_stashpv
               Returns a pointer to the stash for a specified
               package.  Uses "strlen" to determine the length of
               "name", then calls "gv_stashpvn()".

                       HV*     gv_stashpv(const char* name, I32 flags)

       gv_stashpvn
               Returns a pointer to the stash for a specified
               package.  The "namelen" parameter indicates the
               length of the "name", in bytes.  "flags" is passed
               to "gv_fetchpvn_flags()", so if set to "GV_ADD"
               then the package will be created if it does not
               already exist.  If the package does not exist and
               "flags" is 0 (or any other setting that does not
               create packages) then NULL is returned.

                       HV*     gv_stashpvn(const char* name, U32 namelen, I32 flags)




perl v5.10.1                2010-03-17                         17





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       gv_stashpvs
               Like "gv_stashpvn", but takes a literal string
               instead of a string/length pair.

                       HV*     gv_stashpvs(const char* name, I32 create)

       gv_stashsv
               Returns a pointer to the stash for a specified
               package.  See "gv_stashpvn".

                       HV*     gv_stashsv(SV* sv, I32 flags)

Handy Values
       Nullav  Null AV pointer.

       Nullch  Null character pointer.

       Nullcv  Null CV pointer.

       Nullhv  Null HV pointer.

       Nullsv  Null SV pointer.

Hash Manipulation Functions
       get_hv  Returns the HV of the specified Perl hash.
               "flags" are passed to "gv_fetchpv". If "GV_ADD" is
               set and the Perl variable does not exist then it
               will be created.  If "flags" is zero and the
               variable does not exist then NULL is returned.

               NOTE: the perl_ form of this function is
               deprecated.

                       HV*     get_hv(const char *name, I32 flags)

       HEf_SVKEY
               This flag, used in the length slot of hash entries
               and magic structures, specifies the structure
               contains an "SV*" pointer where a "char*" pointer
               is to be expected. (For information only--not to
               be used).

       HeHASH  Returns the computed hash stored in the hash
               entry.

                       U32     HeHASH(HE* he)

       HeKEY   Returns the actual pointer stored in the key slot
               of the hash entry. The pointer may be either
               "char*" or "SV*", depending on the value of
               "HeKLEN()".  Can be assigned to.  The "HePV()" or
               "HeSVKEY()" macros are usually preferable for
               finding the value of a key.




perl v5.10.1                2010-03-17                         18





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       void*   HeKEY(HE* he)

       HeKLEN  If this is negative, and amounts to "HEf_SVKEY",
               it indicates the entry holds an "SV*" key.
               Otherwise, holds the actual length of the key.
               Can be assigned to. The "HePV()" macro is usually
               preferable for finding key lengths.

                       STRLEN  HeKLEN(HE* he)

       HePV    Returns the key slot of the hash entry as a
               "char*" value, doing any necessary dereferencing
               of possibly "SV*" keys.  The length of the string
               is placed in "len" (this is a macro, so do not use
               &len).  If you do not care about what the length
               of the key is, you may use the global variable
               "PL_na", though this is rather less efficient than
               using a local variable.  Remember though, that
               hash keys in perl are free to contain embedded
               nulls, so using "strlen()" or similar is not a
               good way to find the length of hash keys. This is
               very similar to the "SvPV()" macro described
               elsewhere in this document. See also "HeUTF8".

               If you are using "HePV" to get values to pass to
               "newSVpvn()" to create a new SV, you should
               consider using "newSVhek(HeKEY_hek(he))" as it is
               more efficient.

                       char*   HePV(HE* he, STRLEN len)

       HeSVKEY Returns the key as an "SV*", or "NULL" if the hash
               entry does not contain an "SV*" key.

                       SV*     HeSVKEY(HE* he)

       HeSVKEY_force
               Returns the key as an "SV*".  Will create and
               return a temporary mortal "SV*" if the hash entry
               contains only a "char*" key.

                       SV*     HeSVKEY_force(HE* he)

       HeSVKEY_set
               Sets the key to a given "SV*", taking care to set
               the appropriate flags to indicate the presence of
               an "SV*" key, and returns the same "SV*".

                       SV*     HeSVKEY_set(HE* he, SV* sv)

       HeUTF8  Returns whether the "char *" value returned by
               "HePV" is encoded in UTF-8, doing any necessary
               dereferencing of possibly "SV*" keys.  The value
               returned will be 0 or non-0, not necessarily 1 (or



perl v5.10.1                2010-03-17                         19





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               even a value with any low bits set), so do not
               blindly assign this to a "bool" variable, as
               "bool" may be a typedef for "char".

                       char*   HeUTF8(HE* he, STRLEN len)

       HeVAL   Returns the value slot (type "SV*") stored in the
               hash entry.

                       SV*     HeVAL(HE* he)

       HvNAME  Returns the package name of a stash, or NULL if
               "stash" isn't a stash.  See "SvSTASH", "CvSTASH".

                       char*   HvNAME(HV* stash)

       hv_assert
               Check that a hash is in an internally consistent
               state.

                       void    hv_assert(HV *hv)

       hv_clear
               Clears a hash, making it empty.

                       void    hv_clear(HV* hv)

       hv_clear_placeholders
               Clears any placeholders from a hash.  If a
               restricted hash has any of its keys marked as
               readonly and the key is subsequently deleted, the
               key is not actually deleted but is marked by
               assigning it a value of &PL_sv_placeholder.  This
               tags it so it will be ignored by future operations
               such as iterating over the hash, but will still
               allow the hash to have a value reassigned to the
               key at some future point.  This function clears
               any such placeholder keys from the hash.  See
               Hash::Util::lock_keys() for an example of its use.

                       void    hv_clear_placeholders(HV *hv)

       hv_delete
               Deletes a key/value pair in the hash.  The value
               SV is removed from the hash and returned to the
               caller.  The "klen" is the length of the key.  The
               "flags" value will normally be zero; if set to
               G_DISCARD then NULL will be returned.

                       SV*     hv_delete(HV *hv, const char *key, I32 klen, I32 flags)

       hv_delete_ent
               Deletes a key/value pair in the hash.  The value
               SV is removed from the hash and returned to the



perl v5.10.1                2010-03-17                         20





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               caller.  The "flags" value will normally be zero;
               if set to G_DISCARD then NULL will be returned.
               "hash" can be a valid precomputed hash value, or 0
               to ask for it to be computed.

                       SV*     hv_delete_ent(HV *hv, SV *keysv, I32 flags, U32 hash)

       hv_exists
               Returns a boolean indicating whether the specified
               hash key exists.  The "klen" is the length of the
               key.

                       bool    hv_exists(HV *hv, const char *key, I32 klen)

       hv_exists_ent
               Returns a boolean indicating whether the specified
               hash key exists. "hash" can be a valid precomputed
               hash value, or 0 to ask for it to be computed.

                       bool    hv_exists_ent(HV *hv, SV *keysv, U32 hash)

       hv_fetch
               Returns the SV which corresponds to the specified
               key in the hash.  The "klen" is the length of the
               key.  If "lval" is set then the fetch will be part
               of a store.  Check that the return value is non-
               null before dereferencing it to an "SV*".

               See "Understanding the Magic of Tied Hashes and
               Arrays" in perlguts for more information on how to
               use this function on tied hashes.

                       SV**    hv_fetch(HV *hv, const char *key, I32 klen, I32 lval)

       hv_fetchs
               Like "hv_fetch", but takes a literal string
               instead of a string/length pair.

                       SV**    hv_fetchs(HV* tb, const char* key, I32 lval)

       hv_fetch_ent
               Returns the hash entry which corresponds to the
               specified key in the hash.  "hash" must be a valid
               precomputed hash number for the given "key", or 0
               if you want the function to compute it.  IF "lval"
               is set then the fetch will be part of a store.
               Make sure the return value is non-null before
               accessing it.  The return value when "tb" is a
               tied hash is a pointer to a static location, so be
               sure to make a copy of the structure if you need
               to store it somewhere.

               See "Understanding the Magic of Tied Hashes and
               Arrays" in perlguts for more information on how to



perl v5.10.1                2010-03-17                         21





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               use this function on tied hashes.

                       HE*     hv_fetch_ent(HV *hv, SV *keysv, I32 lval, U32 hash)

       hv_iterinit
               Prepares a starting point to traverse a hash
               table.  Returns the number of keys in the hash
               (i.e. the same as "HvKEYS(tb)").  The return value
               is currently only meaningful for hashes without
               tie magic.

               NOTE: Before version 5.004_65, "hv_iterinit" used
               to return the number of hash buckets that happen
               to be in use.  If you still need that esoteric
               value, you can get it through the macro
               "HvFILL(tb)".

                       I32     hv_iterinit(HV *hv)

       hv_iterkey
               Returns the key from the current position of the
               hash iterator.  See "hv_iterinit".

                       char*   hv_iterkey(HE* entry, I32* retlen)

       hv_iterkeysv
               Returns the key as an "SV*" from the current
               position of the hash iterator.  The return value
               will always be a mortal copy of the key.  Also see
               "hv_iterinit".

                       SV*     hv_iterkeysv(HE* entry)

       hv_iternext
               Returns entries from a hash iterator.  See
               "hv_iterinit".

               You may call "hv_delete" or "hv_delete_ent" on the
               hash entry that the iterator currently points to,
               without losing your place or invalidating your
               iterator.  Note that in this case the current
               entry is deleted from the hash with your iterator
               holding the last reference to it.  Your iterator
               is flagged to free the entry on the next call to
               "hv_iternext", so you must not discard your
               iterator immediately else the entry will leak -
               call "hv_iternext" to trigger the resource
               deallocation.

                       HE*     hv_iternext(HV *hv)

       hv_iternextsv
               Performs an "hv_iternext", "hv_iterkey", and
               "hv_iterval" in one operation.



perl v5.10.1                2010-03-17                         22





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       SV*     hv_iternextsv(HV *hv, char **key, I32 *retlen)

       hv_iternext_flags
               Returns entries from a hash iterator.  See
               "hv_iterinit" and "hv_iternext".  The "flags"
               value will normally be zero; if
               HV_ITERNEXT_WANTPLACEHOLDERS is set the
               placeholders keys (for restricted hashes) will be
               returned in addition to normal keys. By default
               placeholders are automatically skipped over.
               Currently a placeholder is implemented with a
               value that is &Perl_sv_placeholder. Note that the
               implementation of placeholders and restricted
               hashes may change, and the implementation
               currently is insufficiently abstracted for any
               change to be tidy.

               NOTE: this function is experimental and may change
               or be removed without notice.

                       HE*     hv_iternext_flags(HV *hv, I32 flags)

       hv_iterval
               Returns the value from the current position of the
               hash iterator.  See "hv_iterkey".

                       SV*     hv_iterval(HV *hv, HE *entry)

       hv_magic
               Adds magic to a hash.  See "sv_magic".

                       void    hv_magic(HV *hv, GV *gv, int how)

       hv_scalar
               Evaluates the hash in scalar context and returns
               the result. Handles magic when the hash is tied.

                       SV*     hv_scalar(HV *hv)

       hv_store
               Stores an SV in a hash.  The hash key is specified
               as "key" and "klen" is the length of the key.  The
               "hash" parameter is the precomputed hash value; if
               it is zero then Perl will compute it.  The return
               value will be NULL if the operation failed or if
               the value did not need to be actually stored
               within the hash (as in the case of tied hashes).
               Otherwise it can be dereferenced to get the
               original "SV*".  Note that the caller is
               responsible for suitably incrementing the
               reference count of "val" before the call, and
               decrementing it if the function returned NULL.
               Effectively a successful hv_store takes ownership
               of one reference to "val".  This is usually what



perl v5.10.1                2010-03-17                         23





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               you want; a newly created SV has a reference count
               of one, so if all your code does is create SVs
               then store them in a hash, hv_store will own the
               only reference to the new SV, and your code
               doesn't need to do anything further to tidy up.
               hv_store is not implemented as a call to
               hv_store_ent, and does not create a temporary SV
               for the key, so if your key data is not already in
               SV form then use hv_store in preference to
               hv_store_ent.

               See "Understanding the Magic of Tied Hashes and
               Arrays" in perlguts for more information on how to
               use this function on tied hashes.

                       SV**    hv_store(HV *hv, const char *key, I32 klen, SV *val, U32 hash)

       hv_stores
               Like "hv_store", but takes a literal string
               instead of a string/length pair and omits the hash
               parameter.

                       SV**    hv_stores(HV* tb, const char* key, NULLOK SV* val)

       hv_store_ent
               Stores "val" in a hash.  The hash key is specified
               as "key".  The "hash" parameter is the precomputed
               hash value; if it is zero then Perl will compute
               it.  The return value is the new hash entry so
               created.  It will be NULL if the operation failed
               or if the value did not need to be actually stored
               within the hash (as in the case of tied hashes).
               Otherwise the contents of the return value can be
               accessed using the "He?" macros described here.
               Note that the caller is responsible for suitably
               incrementing the reference count of "val" before
               the call, and decrementing it if the function
               returned NULL.  Effectively a successful
               hv_store_ent takes ownership of one reference to
               "val".  This is usually what you want; a newly
               created SV has a reference count of one, so if all
               your code does is create SVs then store them in a
               hash, hv_store will own the only reference to the
               new SV, and your code doesn't need to do anything
               further to tidy up.  Note that hv_store_ent only
               reads the "key"; unlike "val" it does not take
               ownership of it, so maintaining the correct
               reference count on "key" is entirely the caller's
               responsibility.  hv_store is not implemented as a
               call to hv_store_ent, and does not create a
               temporary SV for the key, so if your key data is
               not already in SV form then use hv_store in
               preference to hv_store_ent.




perl v5.10.1                2010-03-17                         24





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               See "Understanding the Magic of Tied Hashes and
               Arrays" in perlguts for more information on how to
               use this function on tied hashes.

                       HE*     hv_store_ent(HV *hv, SV *key, SV *val, U32 hash)

       hv_undef
               Undefines the hash.

                       void    hv_undef(HV *hv)

       newHV   Creates a new HV.  The reference count is set to
               1.

                       HV*     newHV()

Magical Functions
       mg_clear
               Clear something magical that the SV represents.
               See "sv_magic".

                       int     mg_clear(SV* sv)

       mg_copy Copies the magic from one SV to another.  See
               "sv_magic".

                       int     mg_copy(SV *sv, SV *nsv, const char *key, I32 klen)

       mg_find Finds the magic pointer for type matching the SV.
               See "sv_magic".

                       MAGIC*  mg_find(const SV* sv, int type)

       mg_free Free any magic storage used by the SV.  See
               "sv_magic".

                       int     mg_free(SV* sv)

       mg_get  Do magic after a value is retrieved from the SV.
               See "sv_magic".

                       int     mg_get(SV* sv)

       mg_length
               Report on the SV's length.  See "sv_magic".

                       U32     mg_length(SV* sv)

       mg_magical
               Turns on the magical status of an SV.  See
               "sv_magic".

                       void    mg_magical(SV* sv)




perl v5.10.1                2010-03-17                         25





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       mg_set  Do magic after a value is assigned to the SV.  See
               "sv_magic".

                       int     mg_set(SV* sv)

       SvGETMAGIC
               Invokes "mg_get" on an SV if it has 'get' magic.
               This macro evaluates its argument more than once.

                       void    SvGETMAGIC(SV* sv)

       SvLOCK  Arranges for a mutual exclusion lock to be
               obtained on sv if a suitable module has been
               loaded.

                       void    SvLOCK(SV* sv)

       SvSETMAGIC
               Invokes "mg_set" on an SV if it has 'set' magic.
               This macro evaluates its argument more than once.

                       void    SvSETMAGIC(SV* sv)

       SvSetMagicSV
               Like "SvSetSV", but does any set magic required
               afterwards.

                       void    SvSetMagicSV(SV* dsb, SV* ssv)

       SvSetMagicSV_nosteal
               Like "SvSetSV_nosteal", but does any set magic
               required afterwards.

                       void    SvSetMagicSV_nosteal(SV* dsv, SV* ssv)

       SvSetSV Calls "sv_setsv" if dsv is not the same as ssv.
               May evaluate arguments more than once.

                       void    SvSetSV(SV* dsb, SV* ssv)

       SvSetSV_nosteal
               Calls a non-destructive version of "sv_setsv" if
               dsv is not the same as ssv. May evaluate arguments
               more than once.

                       void    SvSetSV_nosteal(SV* dsv, SV* ssv)

       SvSHARE Arranges for sv to be shared between threads if a
               suitable module has been loaded.

                       void    SvSHARE(SV* sv)

       SvUNLOCK
               Releases a mutual exclusion lock on sv if a



perl v5.10.1                2010-03-17                         26





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               suitable module has been loaded.

                       void    SvUNLOCK(SV* sv)

Memory Management
       Copy    The XSUB-writer's interface to the C "memcpy"
               function.  The "src" is the source, "dest" is the
               destination, "nitems" is the number of items, and
               "type" is the type.  May fail on overlapping
               copies.  See also "Move".

                       void    Copy(void* src, void* dest, int nitems, type)

       CopyD   Like "Copy" but returns dest. Useful for
               encouraging compilers to tail-call optimise.

                       void *  CopyD(void* src, void* dest, int nitems, type)

       Move    The XSUB-writer's interface to the C "memmove"
               function.  The "src" is the source, "dest" is the
               destination, "nitems" is the number of items, and
               "type" is the type.  Can do overlapping moves.
               See also "Copy".

                       void    Move(void* src, void* dest, int nitems, type)

       MoveD   Like "Move" but returns dest. Useful for
               encouraging compilers to tail-call optimise.

                       void *  MoveD(void* src, void* dest, int nitems, type)

       Newx    The XSUB-writer's interface to the C "malloc"
               function.

               In 5.9.3, Newx() and friends replace the older
               New() API, and drops the first parameter, x, a
               debug aid which allowed callers to identify
               themselves.  This aid has been superseded by a new
               build option, PERL_MEM_LOG (see "PERL_MEM_LOG" in
               perlhack).  The older API is still there for use
               in XS modules supporting older perls.

                       void    Newx(void* ptr, int nitems, type)

       Newxc   The XSUB-writer's interface to the C "malloc"
               function, with cast.  See also "Newx".

                       void    Newxc(void* ptr, int nitems, type, cast)

       Newxz   The XSUB-writer's interface to the C "malloc"
               function.  The allocated memory is zeroed with
               "memzero".  See also "Newx".

                       void    Newxz(void* ptr, int nitems, type)



perl v5.10.1                2010-03-17                         27





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       Poison  PoisonWith(0xEF) for catching access to freed
               memory.

                       void    Poison(void* dest, int nitems, type)

       PoisonFree
               PoisonWith(0xEF) for catching access to freed
               memory.

                       void    PoisonFree(void* dest, int nitems, type)

       PoisonNew
               PoisonWith(0xAB) for catching access to allocated
               but uninitialized memory.

                       void    PoisonNew(void* dest, int nitems, type)

       PoisonWith
               Fill up memory with a byte pattern (a byte
               repeated over and over again) that hopefully
               catches attempts to access uninitialized memory.

                       void    PoisonWith(void* dest, int nitems, type, U8 byte)

       Renew   The XSUB-writer's interface to the C "realloc"
               function.

                       void    Renew(void* ptr, int nitems, type)

       Renewc  The XSUB-writer's interface to the C "realloc"
               function, with cast.

                       void    Renewc(void* ptr, int nitems, type, cast)

       Safefree
               The XSUB-writer's interface to the C "free"
               function.

                       void    Safefree(void* ptr)

       savepv  Perl's version of "strdup()". Returns a pointer to
               a newly allocated string which is a duplicate of
               "pv". The size of the string is determined by
               "strlen()". The memory allocated for the new
               string can be freed with the "Safefree()"
               function.

                       char*   savepv(const char* pv)

       savepvn Perl's version of what "strndup()" would be if it
               existed. Returns a pointer to a newly allocated
               string which is a duplicate of the first "len"
               bytes from "pv", plus a trailing NUL byte. The
               memory allocated for the new string can be freed



perl v5.10.1                2010-03-17                         28





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               with the "Safefree()" function.

                       char*   savepvn(const char* pv, I32 len)

       savepvs Like "savepvn", but takes a literal string instead
               of a string/length pair.

                       char*   savepvs(const char* s)

       savesharedpv
               A version of "savepv()" which allocates the
               duplicate string in memory which is shared between
               threads.

                       char*   savesharedpv(const char* pv)

       savesharedpvn
               A version of "savepvn()" which allocates the
               duplicate string in memory which is shared between
               threads. (With the specific difference that a NULL
               pointer is not acceptable)

                       char*   savesharedpvn(const char *const pv, const STRLEN len)

       savesvpv
               A version of "savepv()"/"savepvn()" which gets the
               string to duplicate from the passed in SV using
               "SvPV()"

                       char*   savesvpv(SV* sv)

       StructCopy
               This is an architecture-independent macro to copy
               one structure to another.

                       void    StructCopy(type src, type dest, type)

       Zero    The XSUB-writer's interface to the C "memzero"
               function.  The "dest" is the destination, "nitems"
               is the number of items, and "type" is the type.

                       void    Zero(void* dest, int nitems, type)

       ZeroD   Like "Zero" but returns dest. Useful for
               encouraging compilers to tail-call optimise.

                       void *  ZeroD(void* dest, int nitems, type)

Miscellaneous Functions
       fbm_compile
               Analyses the string in order to make fast searches
               on it using fbm_instr() -- the Boyer-Moore
               algorithm.




perl v5.10.1                2010-03-17                         29





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       void    fbm_compile(SV* sv, U32 flags)

       fbm_instr
               Returns the location of the SV in the string
               delimited by "str" and "strend".  It returns
               "NULL" if the string can't be found.  The "sv"
               does not have to be fbm_compiled, but the search
               will not be as fast then.

                       char*   fbm_instr(unsigned char* big, unsigned char* bigend, SV* littlestr, U32 flags)

       form    Takes a sprintf-style format pattern and
               conventional (non-SV) arguments and returns the
               formatted string.

                   (char *) Perl_form(pTHX_ const char* pat, ...)

               can be used any place a string (char *) is
               required:

                   char * s = Perl_form("%d.%d",major,minor);

               Uses a single private buffer so if you want to
               format several strings you must explicitly copy
               the earlier strings away (and free the copies when
               you are done).

                       char*   form(const char* pat, ...)

       getcwd_sv
               Fill the sv with current working directory

                       int     getcwd_sv(SV* sv)

       my_snprintf
               The C library "snprintf" functionality, if
               available and standards-compliant (uses
               "vsnprintf", actually).  However, if the
               "vsnprintf" is not available, will unfortunately
               use the unsafe "vsprintf" which can overrun the
               buffer (there is an overrun check, but that may be
               too late).  Consider using "sv_vcatpvf" instead,
               or getting "vsnprintf".

                       int     my_snprintf(char *buffer, const Size_t len, const char *format, ...)

       my_sprintf
               The C library "sprintf", wrapped if necessary, to
               ensure that it will return the length of the
               string written to the buffer. Only rare pre-ANSI
               systems need the wrapper function - usually this
               is a direct call to "sprintf".

                       int     my_sprintf(char *buffer, const char *pat, ...)



perl v5.10.1                2010-03-17                         30





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       my_vsnprintf
               The C library "vsnprintf" if available and
               standards-compliant.  However, if if the
               "vsnprintf" is not available, will unfortunately
               use the unsafe "vsprintf" which can overrun the
               buffer (there is an overrun check, but that may be
               too late).  Consider using "sv_vcatpvf" instead,
               or getting "vsnprintf".

                       int     my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)

       new_version
               Returns a new version object based on the passed
               in SV:

                   SV *sv = new_version(SV *ver);

               Does not alter the passed in ver SV.  See
               "upg_version" if you want to upgrade the SV.

                       SV*     new_version(SV *ver)

       scan_version
               Returns a pointer to the next character after the
               parsed version string, as well as upgrading the
               passed in SV to an RV.

               Function must be called with an already existing
               SV like

                   sv = newSV(0);
                   s = scan_version(s, SV *sv, bool qv);

               Performs some preprocessing to the string to
               ensure that it has the correct characteristics of
               a version.  Flags the object if it contains an
               underscore (which denotes this is an alpha
               version).  The boolean qv denotes that the version
               should be interpreted as if it had multiple
               decimals, even if it doesn't.

                       const char*     scan_version(const char *s, SV *rv, bool qv)

       strEQ   Test two strings to see if they are equal.
               Returns true or false.

                       bool    strEQ(char* s1, char* s2)

       strGE   Test two strings to see if the first, "s1", is
               greater than or equal to the second, "s2".
               Returns true or false.

                       bool    strGE(char* s1, char* s2)




perl v5.10.1                2010-03-17                         31





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       strGT   Test two strings to see if the first, "s1", is
               greater than the second, "s2".  Returns true or
               false.

                       bool    strGT(char* s1, char* s2)

       strLE   Test two strings to see if the first, "s1", is
               less than or equal to the second, "s2".  Returns
               true or false.

                       bool    strLE(char* s1, char* s2)

       strLT   Test two strings to see if the first, "s1", is
               less than the second, "s2".  Returns true or
               false.

                       bool    strLT(char* s1, char* s2)

       strNE   Test two strings to see if they are different.
               Returns true or false.

                       bool    strNE(char* s1, char* s2)

       strnEQ  Test two strings to see if they are equal.  The
               "len" parameter indicates the number of bytes to
               compare.  Returns true or false. (A wrapper for
               "strncmp").

                       bool    strnEQ(char* s1, char* s2, STRLEN len)

       strnNE  Test two strings to see if they are different.
               The "len" parameter indicates the number of bytes
               to compare.  Returns true or false. (A wrapper for
               "strncmp").

                       bool    strnNE(char* s1, char* s2, STRLEN len)

       sv_destroyable
               Dummy routine which reports that object can be
               destroyed when there is no sharing module present.
               It ignores its single SV argument, and returns
               'true'.  Exists to avoid test for a NULL function
               pointer and because it could potentially warn
               under some level of strict-ness.

                       bool    sv_destroyable(SV *sv)

       sv_nosharing
               Dummy routine which "shares" an SV when there is
               no sharing module present.  Or "locks" it. Or
               "unlocks" it. In other words, ignores its single
               SV argument.  Exists to avoid test for a NULL
               function pointer and because it could potentially
               warn under some level of strict-ness.



perl v5.10.1                2010-03-17                         32





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       void    sv_nosharing(SV *sv)

       upg_version
               In-place upgrade of the supplied SV to a version
               object.

                   SV *sv = upg_version(SV *sv, bool qv);

               Returns a pointer to the upgraded SV.  Set the
               boolean qv if you want to force this SV to be
               interpreted as an "extended" version.

                       SV*     upg_version(SV *ver, bool qv)

       vcmp    Version object aware cmp.  Both operands must
               already have been converted into version objects.

                       int     vcmp(SV *lhv, SV *rhv)

       vnormal Accepts a version object and returns the
               normalized string representation.  Call like:

                   sv = vnormal(rv);

               NOTE: you can pass either the object directly or
               the SV contained within the RV.

                       SV*     vnormal(SV *vs)

       vnumify Accepts a version object and returns the
               normalized floating point representation.  Call
               like:

                   sv = vnumify(rv);

               NOTE: you can pass either the object directly or
               the SV contained within the RV.

                       SV*     vnumify(SV *vs)

       vstringify
               In order to maintain maximum compatibility with
               earlier versions of Perl, this function will
               return either the floating point notation or the
               multiple dotted notation, depending on whether the
               original version contained 1 or more dots,
               respectively

                       SV*     vstringify(SV *vs)

       vverify Validates that the SV contains a valid version
               object.

                   bool vverify(SV *vobj);



perl v5.10.1                2010-03-17                         33





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               Note that it only confirms the bare minimum
               structure (so as not to get confused by derived
               classes which may contain additional hash
               entries):

                       bool    vverify(SV *vs)

MRO Functions
       mro_get_linear_isa
               Returns either "mro_get_linear_isa_c3" or
               "mro_get_linear_isa_dfs" for the given stash,
               dependant upon which MRO is in effect for that
               stash.  The return value is a read-only AV*.

               You are responsible for "SvREFCNT_inc()" on the
               return value if you plan to store it anywhere
               semi-permanently (otherwise it might be deleted
               out from under you the next time the cache is
               invalidated).

                       AV*     mro_get_linear_isa(HV* stash)

       mro_method_changed_in
               Invalidates method caching on any child classes of
               the given stash, so that they might notice the
               changes in this one.

               Ideally, all instances of "PL_sub_generation++" in
               perl source outside of "mro.c" should be replaced
               by calls to this.

               Perl automatically handles most of the common ways
               a method might be redefined.  However, there are a
               few ways you could change a method in a stash
               without the cache code noticing, in which case you
               need to call this method afterwards:

               1) Directly manipulating the stash HV entries from
               XS code.

               2) Assigning a reference to a readonly scalar
               constant into a stash entry in order to create a
               constant subroutine (like constant.pm does).

               This same method is available from pure perl via,
               "mro::method_changed_in(classname)".

                       void    mro_method_changed_in(HV* stash)

Multicall Functions
       dMULTICALL
               Declare local variables for a multicall. See
               "Lightweight Callbacks" in perlcall.




perl v5.10.1                2010-03-17                         34





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                               dMULTICALL;

       MULTICALL
               Make a lightweight callback. See "Lightweight
               Callbacks" in perlcall.

                               MULTICALL;

       POP_MULTICALL
               Closing bracket for a lightweight callback.  See
               "Lightweight Callbacks" in perlcall.

                               POP_MULTICALL;

       PUSH_MULTICALL
               Opening bracket for a lightweight callback.  See
               "Lightweight Callbacks" in perlcall.

                               PUSH_MULTICALL;

Numeric functions
       grok_bin
               converts a string representing a binary number to
               numeric form.

               On entry start and *len give the string to scan,
               *flags gives conversion flags, and result should
               be NULL or a pointer to an NV.  The scan stops at
               the end of the string, or the first invalid
               character.  Unless "PERL_SCAN_SILENT_ILLDIGIT" is
               set in *flags, encountering an invalid character
               will also trigger a warning.  On return *len is
               set to the length of the scanned string, and
               *flags gives output flags.

               If the value is <= "UV_MAX" it is returned as a
               UV, the output flags are clear, and nothing is
               written to *result. If the value is > UV_MAX
               "grok_bin" returns UV_MAX, sets
               "PERL_SCAN_GREATER_THAN_UV_MAX" in the output
               flags, and writes the value to *result (or the
               value is discarded if result is NULL).

               The binary number may optionally be prefixed with
               "0b" or "b" unless "PERL_SCAN_DISALLOW_PREFIX" is
               set in *flags on entry. If
               "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags
               then the binary number may use '_' characters to
               separate digits.

                       UV      grok_bin(const char* start, STRLEN* len_p, I32* flags, NV *result)

       grok_hex
               converts a string representing a hex number to



perl v5.10.1                2010-03-17                         35





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               numeric form.

               On entry start and *len give the string to scan,
               *flags gives conversion flags, and result should
               be NULL or a pointer to an NV.  The scan stops at
               the end of the string, or the first invalid
               character.  Unless "PERL_SCAN_SILENT_ILLDIGIT" is
               set in *flags, encountering an invalid character
               will also trigger a warning.  On return *len is
               set to the length of the scanned string, and
               *flags gives output flags.

               If the value is <= UV_MAX it is returned as a UV,
               the output flags are clear, and nothing is written
               to *result. If the value is > UV_MAX "grok_hex"
               returns UV_MAX, sets
               "PERL_SCAN_GREATER_THAN_UV_MAX" in the output
               flags, and writes the value to *result (or the
               value is discarded if result is NULL).

               The hex number may optionally be prefixed with
               "0x" or "x" unless "PERL_SCAN_DISALLOW_PREFIX" is
               set in *flags on entry. If
               "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags
               then the hex number may use '_' characters to
               separate digits.

                       UV      grok_hex(const char* start, STRLEN* len_p, I32* flags, NV *result)

       grok_number
               Recognise (or not) a number.  The type of the
               number is returned (0 if unrecognised), otherwise
               it is a bit-ORed combination of IS_NUMBER_IN_UV,
               IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT,
               IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN
               (defined in perl.h).

               If the value of the number can fit an in UV, it is
               returned in the *valuep IS_NUMBER_IN_UV will be
               set to indicate that *valuep is valid,
               IS_NUMBER_IN_UV will never be set unless *valuep
               is valid, but *valuep may have been assigned to
               during processing even though IS_NUMBER_IN_UV is
               not set on return.  If valuep is NULL,
               IS_NUMBER_IN_UV will be set for the same cases as
               when valuep is non-NULL, but no actual assignment
               (or SEGV) will occur.

               IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV
               if trailing decimals were seen (in which case
               *valuep gives the true value truncated to an
               integer), and IS_NUMBER_NEG if the number is
               negative (in which case *valuep holds the absolute
               value).  IS_NUMBER_IN_UV is not set if e notation



perl v5.10.1                2010-03-17                         36





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               was used or the number is larger than a UV.

                       int     grok_number(const char *pv, STRLEN len, UV *valuep)

       grok_numeric_radix
               Scan and skip for a numeric decimal separator
               (radix).

                       bool    grok_numeric_radix(const char **sp, const char *send)

       grok_oct
               converts a string representing an octal number to
               numeric form.

               On entry start and *len give the string to scan,
               *flags gives conversion flags, and result should
               be NULL or a pointer to an NV.  The scan stops at
               the end of the string, or the first invalid
               character.  Unless "PERL_SCAN_SILENT_ILLDIGIT" is
               set in *flags, encountering an invalid character
               will also trigger a warning.  On return *len is
               set to the length of the scanned string, and
               *flags gives output flags.

               If the value is <= UV_MAX it is returned as a UV,
               the output flags are clear, and nothing is written
               to *result. If the value is > UV_MAX "grok_oct"
               returns UV_MAX, sets
               "PERL_SCAN_GREATER_THAN_UV_MAX" in the output
               flags, and writes the value to *result (or the
               value is discarded if result is NULL).

               If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags
               then the octal number may use '_' characters to
               separate digits.

                       UV      grok_oct(const char* start, STRLEN* len_p, I32* flags, NV *result)

       Perl_signbit
               Return a non-zero integer if the sign bit on an NV
               is set, and 0 if it is not.

               If Configure detects this system has a signbit()
               that will work with our NVs, then we just use it
               via the #define in perl.h.  Otherwise, fall back
               on this implementation.  As a first pass, this
               gets everything right except -0.0.  Alas, catching
               -0.0 is the main use for this function, so this is
               not too helpful yet.  Still, at least we have the
               scaffolding in place to support other systems,
               should that prove useful.

               Configure notes:  This function is called
               'Perl_signbit' instead of a plain 'signbit'



perl v5.10.1                2010-03-17                         37





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               because it is easy to imagine a system having a
               signbit() function or macro that doesn't happen to
               work with our particular choice of NVs.  We
               shouldn't just re-#define signbit as Perl_signbit
               and expect the standard system headers to be
               happy.  Also, this is a no-context function (no
               pTHX_) because Perl_signbit() is usually
               re-#defined in perl.h as a simple macro call to
               the system's signbit().  Users should just always
               call Perl_signbit().

               NOTE: this function is experimental and may change
               or be removed without notice.

                       int     Perl_signbit(NV f)

       scan_bin
               For backwards compatibility. Use "grok_bin"
               instead.

                       NV      scan_bin(const char* start, STRLEN len, STRLEN* retlen)

       scan_hex
               For backwards compatibility. Use "grok_hex"
               instead.

                       NV      scan_hex(const char* start, STRLEN len, STRLEN* retlen)

       scan_oct
               For backwards compatibility. Use "grok_oct"
               instead.

                       NV      scan_oct(const char* start, STRLEN len, STRLEN* retlen)

Optree Manipulation Functions
       cv_const_sv
               If "cv" is a constant sub eligible for inlining.
               returns the constant value returned by the sub.
               Otherwise, returns NULL.

               Constant subs can be created with "newCONSTSUB" or
               as described in "Constant Functions" in perlsub.

                       SV*     cv_const_sv(CV* cv)

       newCONSTSUB
               Creates a constant sub equivalent to Perl "sub FOO
               () { 123 }" which is eligible for inlining at
               compile-time.

                       CV*     newCONSTSUB(HV* stash, const char* name, SV* sv)

       newXS   Used by "xsubpp" to hook up XSUBs as Perl subs.
               filename needs to be static storage, as it is used



perl v5.10.1                2010-03-17                         38





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               directly as CvFILE(), without a copy being made.

Pad Data Structures
       pad_sv  Get the value at offset po in the current pad.
               Use macro PAD_SV instead of calling this function
               directly.

                       SV*     pad_sv(PADOFFSET po)

Per-Interpreter Variables
       PL_modglobal
               "PL_modglobal" is a general purpose, interpreter
               global HV for use by extensions that need to keep
               information on a per-interpreter basis.  In a
               pinch, it can also be used as a symbol table for
               extensions to share data among each other.  It is
               a good idea to use keys prefixed by the package
               name of the extension that owns the data.

                       HV*     PL_modglobal

       PL_na   A convenience variable which is typically used
               with "SvPV" when one doesn't care about the length
               of the string.  It is usually more efficient to
               either declare a local variable and use that
               instead or to use the "SvPV_nolen" macro.

                       STRLEN  PL_na

       PL_sv_no
               This is the "false" SV.  See "PL_sv_yes".  Always
               refer to this as &PL_sv_no.

                       SV      PL_sv_no

       PL_sv_undef
               This is the "undef" SV.  Always refer to this as
               &PL_sv_undef.

                       SV      PL_sv_undef

       PL_sv_yes
               This is the "true" SV.  See "PL_sv_no".  Always
               refer to this as &PL_sv_yes.

                       SV      PL_sv_yes

REGEXP Functions
       SvRX    Convenience macro to get the REGEXP from a SV.
               This is approximately equivalent to the following
               snippet:






perl v5.10.1                2010-03-17                         39





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                   if (SvMAGICAL(sv))
                       mg_get(sv);
                   if (SvROK(sv) &&
                       (tmpsv = (SV*)SvRV(sv)) &&
                       SvTYPE(tmpsv) == SVt_PVMG &&
                       (tmpmg = mg_find(tmpsv, PERL_MAGIC_qr)))
                   {
                       return (REGEXP *)tmpmg->mg_obj;
                   }

               NULL will be returned if a REGEXP* is not found.

                       REGEXP *        SvRX(SV *sv)

       SvRXOK  Returns a boolean indicating whether the SV
               contains qr magic (PERL_MAGIC_qr).

               If you want to do something with the REGEXP* later
               use SvRX instead and check for NULL.

                       bool    SvRXOK(SV* sv)

Simple Exception Handling Macros
       dXCPT   Set up necessary local variables for exception
               handling.  See "Exception Handling" in perlguts.

                               dXCPT;

       XCPT_CATCH
               Introduces a catch block.  See "Exception
               Handling" in perlguts.

       XCPT_RETHROW
               Rethrows a previously caught exception.  See
               "Exception Handling" in perlguts.

                               XCPT_RETHROW;

       XCPT_TRY_END
               Ends a try block.  See "Exception Handling" in
               perlguts.

       XCPT_TRY_START
               Starts a try block.  See "Exception Handling" in
               perlguts.

Stack Manipulation Macros
       dMARK   Declare a stack marker variable, "mark", for the
               XSUB.  See "MARK" and "dORIGMARK".

                               dMARK;

       dORIGMARK
               Saves the original stack mark for the XSUB.  See



perl v5.10.1                2010-03-17                         40





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "ORIGMARK".

                               dORIGMARK;

       dSP     Declares a local copy of perl's stack pointer for
               the XSUB, available via the "SP" macro.  See "SP".

                               dSP;

       EXTEND  Used to extend the argument stack for an XSUB's
               return values. Once used, guarantees that there is
               room for at least "nitems" to be pushed onto the
               stack.

                       void    EXTEND(SP, int nitems)

       MARK    Stack marker variable for the XSUB.  See "dMARK".

       mPUSHi  Push an integer onto the stack.  The stack must
               have room for this element.  Does not use "TARG".
               See also "PUSHi", "mXPUSHi" and "XPUSHi".

                       void    mPUSHi(IV iv)

       mPUSHn  Push a double onto the stack.  The stack must have
               room for this element.  Does not use "TARG".  See
               also "PUSHn", "mXPUSHn" and "XPUSHn".

                       void    mPUSHn(NV nv)

       mPUSHp  Push a string onto the stack.  The stack must have
               room for this element.  The "len" indicates the
               length of the string.  Does not use "TARG".  See
               also "PUSHp", "mXPUSHp" and "XPUSHp".

                       void    mPUSHp(char* str, STRLEN len)

       mPUSHs  Push an SV onto the stack and mortalizes the SV.
               The stack must have room for this element.  Does
               not use "TARG".  See also "PUSHs" and "mXPUSHs".

                       void    mPUSHs(SV* sv)

       mPUSHu  Push an unsigned integer onto the stack.  The
               stack must have room for this element.  Does not
               use "TARG".  See also "PUSHu", "mXPUSHu" and
               "XPUSHu".

                       void    mPUSHu(UV uv)

       mXPUSHi Push an integer onto the stack, extending the
               stack if necessary.  Does not use "TARG".  See
               also "XPUSHi", "mPUSHi" and "PUSHi".




perl v5.10.1                2010-03-17                         41





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       void    mXPUSHi(IV iv)

       mXPUSHn Push a double onto the stack, extending the stack
               if necessary.  Does not use "TARG".  See also
               "XPUSHn", "mPUSHn" and "PUSHn".

                       void    mXPUSHn(NV nv)

       mXPUSHp Push a string onto the stack, extending the stack
               if necessary.  The "len" indicates the length of
               the string.  Does not use "TARG".  See also
               "XPUSHp", "mPUSHp" and "PUSHp".

                       void    mXPUSHp(char* str, STRLEN len)

       mXPUSHs Push an SV onto the stack, extending the stack if
               necessary and mortalizes the SV.  Does not use
               "TARG".  See also "XPUSHs" and "mPUSHs".

                       void    mXPUSHs(SV* sv)

       mXPUSHu Push an unsigned integer onto the stack, extending
               the stack if necessary.  Does not use "TARG".  See
               also "XPUSHu", "mPUSHu" and "PUSHu".

                       void    mXPUSHu(UV uv)

       ORIGMARK
               The original stack mark for the XSUB.  See
               "dORIGMARK".

       POPi    Pops an integer off the stack.

                       IV      POPi

       POPl    Pops a long off the stack.

                       long    POPl

       POPn    Pops a double off the stack.

                       NV      POPn

       POPp    Pops a string off the stack. Deprecated. New code
               should use POPpx.

                       char*   POPp

       POPpbytex
               Pops a string off the stack which must consist of
               bytes i.e. characters < 256.

                       char*   POPpbytex




perl v5.10.1                2010-03-17                         42





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       POPpx   Pops a string off the stack.

                       char*   POPpx

       POPs    Pops an SV off the stack.

                       SV*     POPs

       PUSHi   Push an integer onto the stack.  The stack must
               have room for this element.  Handles 'set' magic.
               Uses "TARG", so "dTARGET" or "dXSTARG" should be
               called to declare it.  Do not call multiple
               "TARG"-oriented macros to return lists from XSUB's
               - see "mPUSHi" instead.  See also "XPUSHi" and
               "mXPUSHi".

                       void    PUSHi(IV iv)

       PUSHMARK
               Opening bracket for arguments on a callback.  See
               "PUTBACK" and perlcall.

                       void    PUSHMARK(SP)

       PUSHmortal
               Push a new mortal SV onto the stack.  The stack
               must have room for this element.  Does not use
               "TARG".  See also "PUSHs", "XPUSHmortal" and
               "XPUSHs".

                       void    PUSHmortal()

       PUSHn   Push a double onto the stack.  The stack must have
               room for this element.  Handles 'set' magic.  Uses
               "TARG", so "dTARGET" or "dXSTARG" should be called
               to declare it.  Do not call multiple
               "TARG"-oriented macros to return lists from XSUB's
               - see "mPUSHn" instead.  See also "XPUSHn" and
               "mXPUSHn".

                       void    PUSHn(NV nv)

       PUSHp   Push a string onto the stack.  The stack must have
               room for this element.  The "len" indicates the
               length of the string.  Handles 'set' magic.  Uses
               "TARG", so "dTARGET" or "dXSTARG" should be called
               to declare it.  Do not call multiple
               "TARG"-oriented macros to return lists from XSUB's
               - see "mPUSHp" instead.  See also "XPUSHp" and
               "mXPUSHp".

                       void    PUSHp(char* str, STRLEN len)

       PUSHs   Push an SV onto the stack.  The stack must have



perl v5.10.1                2010-03-17                         43





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               room for this element.  Does not handle 'set'
               magic.  Does not use "TARG".  See also
               "PUSHmortal", "XPUSHs" and "XPUSHmortal".

                       void    PUSHs(SV* sv)

       PUSHu   Push an unsigned integer onto the stack.  The
               stack must have room for this element.  Handles
               'set' magic.  Uses "TARG", so "dTARGET" or
               "dXSTARG" should be called to declare it.  Do not
               call multiple "TARG"-oriented macros to return
               lists from XSUB's - see "mPUSHu" instead.  See
               also "XPUSHu" and "mXPUSHu".

                       void    PUSHu(UV uv)

       PUTBACK Closing bracket for XSUB arguments.  This is
               usually handled by "xsubpp".  See "PUSHMARK" and
               perlcall for other uses.

                               PUTBACK;

       SP      Stack pointer.  This is usually handled by
               "xsubpp".  See "dSP" and "SPAGAIN".

       SPAGAIN Refetch the stack pointer.  Used after a callback.
               See perlcall.

                               SPAGAIN;

       XPUSHi  Push an integer onto the stack, extending the
               stack if necessary.  Handles 'set' magic.  Uses
               "TARG", so "dTARGET" or "dXSTARG" should be called
               to declare it.  Do not call multiple
               "TARG"-oriented macros to return lists from XSUB's
               - see "mXPUSHi" instead.  See also "PUSHi" and
               "mPUSHi".

                       void    XPUSHi(IV iv)

       XPUSHmortal
               Push a new mortal SV onto the stack, extending the
               stack if necessary.  Does not use "TARG".  See
               also "XPUSHs", "PUSHmortal" and "PUSHs".

                       void    XPUSHmortal()

       XPUSHn  Push a double onto the stack, extending the stack
               if necessary.  Handles 'set' magic.  Uses "TARG",
               so "dTARGET" or "dXSTARG" should be called to
               declare it.  Do not call multiple "TARG"-oriented
               macros to return lists from XSUB's - see "mXPUSHn"
               instead.  See also "PUSHn" and "mPUSHn".




perl v5.10.1                2010-03-17                         44





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       void    XPUSHn(NV nv)

       XPUSHp  Push a string onto the stack, extending the stack
               if necessary.  The "len" indicates the length of
               the string.  Handles 'set' magic.  Uses "TARG", so
               "dTARGET" or "dXSTARG" should be called to declare
               it.  Do not call multiple "TARG"-oriented macros
               to return lists from XSUB's - see "mXPUSHp"
               instead.  See also "PUSHp" and "mPUSHp".

                       void    XPUSHp(char* str, STRLEN len)

       XPUSHs  Push an SV onto the stack, extending the stack if
               necessary.  Does not handle 'set' magic.  Does not
               use "TARG".  See also "XPUSHmortal", "PUSHs" and
               "PUSHmortal".

                       void    XPUSHs(SV* sv)

       XPUSHu  Push an unsigned integer onto the stack, extending
               the stack if necessary.  Handles 'set' magic.
               Uses "TARG", so "dTARGET" or "dXSTARG" should be
               called to declare it.  Do not call multiple
               "TARG"-oriented macros to return lists from XSUB's
               - see "mXPUSHu" instead.  See also "PUSHu" and
               "mPUSHu".

                       void    XPUSHu(UV uv)

       XSRETURN
               Return from XSUB, indicating number of items on
               the stack.  This is usually handled by "xsubpp".

                       void    XSRETURN(int nitems)

       XSRETURN_EMPTY
               Return an empty list from an XSUB immediately.

                               XSRETURN_EMPTY;

       XSRETURN_IV
               Return an integer from an XSUB immediately.  Uses
               "XST_mIV".

                       void    XSRETURN_IV(IV iv)

       XSRETURN_NO
               Return &PL_sv_no from an XSUB immediately.  Uses
               "XST_mNO".

                               XSRETURN_NO;

       XSRETURN_NV
               Return a double from an XSUB immediately.  Uses



perl v5.10.1                2010-03-17                         45





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "XST_mNV".

                       void    XSRETURN_NV(NV nv)

       XSRETURN_PV
               Return a copy of a string from an XSUB
               immediately.  Uses "XST_mPV".

                       void    XSRETURN_PV(char* str)

       XSRETURN_UNDEF
               Return &PL_sv_undef from an XSUB immediately.
               Uses "XST_mUNDEF".

                               XSRETURN_UNDEF;

       XSRETURN_UV
               Return an integer from an XSUB immediately.  Uses
               "XST_mUV".

                       void    XSRETURN_UV(IV uv)

       XSRETURN_YES
               Return &PL_sv_yes from an XSUB immediately.  Uses
               "XST_mYES".

                               XSRETURN_YES;

       XST_mIV Place an integer into the specified position "pos"
               on the stack.  The value is stored in a new mortal
               SV.

                       void    XST_mIV(int pos, IV iv)

       XST_mNO Place &PL_sv_no into the specified position "pos"
               on the stack.

                       void    XST_mNO(int pos)

       XST_mNV Place a double into the specified position "pos"
               on the stack.  The value is stored in a new mortal
               SV.

                       void    XST_mNV(int pos, NV nv)

       XST_mPV Place a copy of a string into the specified
               position "pos" on the stack.  The value is stored
               in a new mortal SV.

                       void    XST_mPV(int pos, char* str)

       XST_mUNDEF
               Place &PL_sv_undef into the specified position
               "pos" on the stack.



perl v5.10.1                2010-03-17                         46





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       void    XST_mUNDEF(int pos)

       XST_mYES
               Place &PL_sv_yes into the specified position "pos"
               on the stack.

                       void    XST_mYES(int pos)

SV Flags
       svtype  An enum of flags for Perl types.  These are found
               in the file sv.h in the "svtype" enum.  Test these
               flags with the "SvTYPE" macro.

       SVt_IV  Integer type flag for scalars.  See "svtype".

       SVt_NV  Double type flag for scalars.  See "svtype".

       SVt_PV  Pointer type flag for scalars.  See "svtype".

       SVt_PVAV
               Type flag for arrays.  See "svtype".

       SVt_PVCV
               Type flag for code refs.  See "svtype".

       SVt_PVHV
               Type flag for hashes.  See "svtype".

       SVt_PVMG
               Type flag for blessed scalars.  See "svtype".

SV Manipulation Functions
       croak_xs_usage
               A specialised variant of "croak()" for emitting
               the usage message for xsubs

                   croak_xs_usage(cv, "eee_yow");

               works out the package name and subroutine name
               from "cv", and then calls "croak()". Hence if "cv"
               is &ouch::awk, it would call "croak" as:

                   Perl_croak(aTHX_ "Usage %s::%s(%s)", "ouch" "awk", "eee_yow");

                       void    croak_xs_usage(const CV *const cv, const char *const params)

       get_sv  Returns the SV of the specified Perl scalar.
               "flags" are passed to "gv_fetchpv". If "GV_ADD" is
               set and the Perl variable does not exist then it
               will be created.  If "flags" is zero and the
               variable does not exist then NULL is returned.

               NOTE: the perl_ form of this function is
               deprecated.



perl v5.10.1                2010-03-17                         47





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       SV*     get_sv(const char *name, I32 flags)

       newRV_inc
               Creates an RV wrapper for an SV.  The reference
               count for the original SV is incremented.

                       SV*     newRV_inc(SV* sv)

       newSVpvn_utf8
               Creates a new SV and copies a string into it.  If
               utf8 is true, calls "SvUTF8_on" on the new SV.
               Implemented as a wrapper around "newSVpvn_flags".

                       SV*     newSVpvn_utf8(NULLOK const char* s, STRLEN len, U32 utf8)

       SvCUR   Returns the length of the string which is in the
               SV.  See "SvLEN".

                       STRLEN  SvCUR(SV* sv)

       SvCUR_set
               Set the current length of the string which is in
               the SV.  See "SvCUR" and "SvIV_set".

                       void    SvCUR_set(SV* sv, STRLEN len)

       SvEND   Returns a pointer to the last character in the
               string which is in the SV.  See "SvCUR".  Access
               the character as *(SvEND(sv)).

                       char*   SvEND(SV* sv)

       SvGAMAGIC
               Returns true if the SV has get magic or
               overloading. If either is true then the scalar is
               active data, and has the potential to return a new
               value every time it is accessed. Hence you must be
               careful to only read it once per user logical
               operation and work with that returned value. If
               neither is true then the scalar's value cannot
               change unless written to.

                       U32     SvGAMAGIC(SV* sv)

       SvGROW  Expands the character buffer in the SV so that it
               has room for the indicated number of bytes
               (remember to reserve space for an extra trailing
               NUL character).  Calls "sv_grow" to perform the
               expansion if necessary.  Returns a pointer to the
               character buffer.

                       char *  SvGROW(SV* sv, STRLEN len)

       SvIOK   Returns a U32 value indicating whether the SV



perl v5.10.1                2010-03-17                         48





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               contains an integer.

                       U32     SvIOK(SV* sv)

       SvIOKp  Returns a U32 value indicating whether the SV
               contains an integer.  Checks the private setting.
               Use "SvIOK" instead.

                       U32     SvIOKp(SV* sv)

       SvIOK_notUV
               Returns a boolean indicating whether the SV
               contains a signed integer.

                       bool    SvIOK_notUV(SV* sv)

       SvIOK_off
               Unsets the IV status of an SV.

                       void    SvIOK_off(SV* sv)

       SvIOK_on
               Tells an SV that it is an integer.

                       void    SvIOK_on(SV* sv)

       SvIOK_only
               Tells an SV that it is an integer and disables all
               other OK bits.

                       void    SvIOK_only(SV* sv)

       SvIOK_only_UV
               Tells and SV that it is an unsigned integer and
               disables all other OK bits.

                       void    SvIOK_only_UV(SV* sv)

       SvIOK_UV
               Returns a boolean indicating whether the SV
               contains an unsigned integer.

                       bool    SvIOK_UV(SV* sv)

       SvIsCOW Returns a boolean indicating whether the SV is
               Copy-On-Write. (either shared hash key scalars, or
               full Copy On Write scalars if 5.9.0 is configured
               for COW)

                       bool    SvIsCOW(SV* sv)

       SvIsCOW_shared_hash
               Returns a boolean indicating whether the SV is
               Copy-On-Write shared hash key scalar.



perl v5.10.1                2010-03-17                         49





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       bool    SvIsCOW_shared_hash(SV* sv)

       SvIV    Coerces the given SV to an integer and returns it.
               See "SvIVx" for a version which guarantees to
               evaluate sv only once.

                       IV      SvIV(SV* sv)

       SvIVX   Returns the raw value in the SV's IV slot, without
               checks or conversions.  Only use when you are sure
               SvIOK is true. See also "SvIV()".

                       IV      SvIVX(SV* sv)

       SvIVx   Coerces the given SV to an integer and returns it.
               Guarantees to evaluate "sv" only once. Only use
               this if "sv" is an expression with side effects,
               otherwise use the more efficient "SvIV".

                       IV      SvIVx(SV* sv)

       SvIV_nomg
               Like "SvIV" but doesn't process magic.

                       IV      SvIV_nomg(SV* sv)

       SvIV_set
               Set the value of the IV pointer in sv to val.  It
               is possible to perform the same function of this
               macro with an lvalue assignment to "SvIVX".  With
               future Perls, however, it will be more efficient
               to use "SvIV_set" instead of the lvalue assignment
               to "SvIVX".

                       void    SvIV_set(SV* sv, IV val)

       SvLEN   Returns the size of the string buffer in the SV,
               not including any part attributable to "SvOOK".
               See "SvCUR".

                       STRLEN  SvLEN(SV* sv)

       SvLEN_set
               Set the actual length of the string which is in
               the SV.  See "SvIV_set".

                       void    SvLEN_set(SV* sv, STRLEN len)

       SvMAGIC_set
               Set the value of the MAGIC pointer in sv to val.
               See "SvIV_set".

                       void    SvMAGIC_set(SV* sv, MAGIC* val)




perl v5.10.1                2010-03-17                         50





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       SvNIOK  Returns a U32 value indicating whether the SV
               contains a number, integer or double.

                       U32     SvNIOK(SV* sv)

       SvNIOKp Returns a U32 value indicating whether the SV
               contains a number, integer or double.  Checks the
               private setting.  Use "SvNIOK" instead.

                       U32     SvNIOKp(SV* sv)

       SvNIOK_off
               Unsets the NV/IV status of an SV.

                       void    SvNIOK_off(SV* sv)

       SvNOK   Returns a U32 value indicating whether the SV
               contains a double.

                       U32     SvNOK(SV* sv)

       SvNOKp  Returns a U32 value indicating whether the SV
               contains a double.  Checks the private setting.
               Use "SvNOK" instead.

                       U32     SvNOKp(SV* sv)

       SvNOK_off
               Unsets the NV status of an SV.

                       void    SvNOK_off(SV* sv)

       SvNOK_on
               Tells an SV that it is a double.

                       void    SvNOK_on(SV* sv)

       SvNOK_only
               Tells an SV that it is a double and disables all
               other OK bits.

                       void    SvNOK_only(SV* sv)

       SvNV    Coerce the given SV to a double and return it. See
               "SvNVx" for a version which guarantees to evaluate
               sv only once.

                       NV      SvNV(SV* sv)

       SvNVX   Returns the raw value in the SV's NV slot, without
               checks or conversions.  Only use when you are sure
               SvNOK is true. See also "SvNV()".

                       NV      SvNVX(SV* sv)



perl v5.10.1                2010-03-17                         51





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       SvNVx   Coerces the given SV to a double and returns it.
               Guarantees to evaluate "sv" only once. Only use
               this if "sv" is an expression with side effects,
               otherwise use the more efficient "SvNV".

                       NV      SvNVx(SV* sv)

       SvNV_set
               Set the value of the NV pointer in sv to val.  See
               "SvIV_set".

                       void    SvNV_set(SV* sv, NV val)

       SvOK    Returns a U32 value indicating whether the value
               is defined. This is only meaningful for scalars.

                       U32     SvOK(SV* sv)

       SvOOK   Returns a U32 indicating whether the SvIVX is a
               valid offset value for the SvPVX.  This hack is
               used internally to speed up removal of characters
               from the beginning of a SvPV.  When SvOOK is true,
               then the start of the allocated string buffer is
               really (SvPVX - SvIVX).

                       U32     SvOOK(SV* sv)

       SvPOK   Returns a U32 value indicating whether the SV
               contains a character string.

                       U32     SvPOK(SV* sv)

       SvPOKp  Returns a U32 value indicating whether the SV
               contains a character string.  Checks the private
               setting.  Use "SvPOK" instead.

                       U32     SvPOKp(SV* sv)

       SvPOK_off
               Unsets the PV status of an SV.

                       void    SvPOK_off(SV* sv)

       SvPOK_on
               Tells an SV that it is a string.

                       void    SvPOK_on(SV* sv)

       SvPOK_only
               Tells an SV that it is a string and disables all
               other OK bits.  Will also turn off the UTF-8
               status.

                       void    SvPOK_only(SV* sv)



perl v5.10.1                2010-03-17                         52





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       SvPOK_only_UTF8
               Tells an SV that it is a string and disables all
               other OK bits, and leaves the UTF-8 status as it
               was.

                       void    SvPOK_only_UTF8(SV* sv)

       SvPV    Returns a pointer to the string in the SV, or a
               stringified form of the SV if the SV does not
               contain a string.  The SV may cache the
               stringified version becoming "SvPOK".  Handles
               'get' magic. See also "SvPVx" for a version which
               guarantees to evaluate sv only once.

                       char*   SvPV(SV* sv, STRLEN len)

       SvPVbyte
               Like "SvPV", but converts sv to byte
               representation first if necessary.

                       char*   SvPVbyte(SV* sv, STRLEN len)

       SvPVbytex
               Like "SvPV", but converts sv to byte
               representation first if necessary.  Guarantees to
               evaluate sv only once; use the more efficient
               "SvPVbyte" otherwise.

                       char*   SvPVbytex(SV* sv, STRLEN len)

       SvPVbytex_force
               Like "SvPV_force", but converts sv to byte
               representation first if necessary.  Guarantees to
               evaluate sv only once; use the more efficient
               "SvPVbyte_force" otherwise.

                       char*   SvPVbytex_force(SV* sv, STRLEN len)

       SvPVbyte_force
               Like "SvPV_force", but converts sv to byte
               representation first if necessary.

                       char*   SvPVbyte_force(SV* sv, STRLEN len)

       SvPVbyte_nolen
               Like "SvPV_nolen", but converts sv to byte
               representation first if necessary.

                       char*   SvPVbyte_nolen(SV* sv)

       SvPVutf8
               Like "SvPV", but converts sv to utf8 first if
               necessary.




perl v5.10.1                2010-03-17                         53





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       char*   SvPVutf8(SV* sv, STRLEN len)

       SvPVutf8x
               Like "SvPV", but converts sv to utf8 first if
               necessary.  Guarantees to evaluate sv only once;
               use the more efficient "SvPVutf8" otherwise.

                       char*   SvPVutf8x(SV* sv, STRLEN len)

       SvPVutf8x_force
               Like "SvPV_force", but converts sv to utf8 first
               if necessary.  Guarantees to evaluate sv only
               once; use the more efficient "SvPVutf8_force"
               otherwise.

                       char*   SvPVutf8x_force(SV* sv, STRLEN len)

       SvPVutf8_force
               Like "SvPV_force", but converts sv to utf8 first
               if necessary.

                       char*   SvPVutf8_force(SV* sv, STRLEN len)

       SvPVutf8_nolen
               Like "SvPV_nolen", but converts sv to utf8 first
               if necessary.

                       char*   SvPVutf8_nolen(SV* sv)

       SvPVX   Returns a pointer to the physical string in the
               SV.  The SV must contain a string.

                       char*   SvPVX(SV* sv)

       SvPVx   A version of "SvPV" which guarantees to evaluate
               "sv" only once.  Only use this if "sv" is an
               expression with side effects, otherwise use the
               more efficient "SvPVX".

                       char*   SvPVx(SV* sv, STRLEN len)

       SvPV_force
               Like "SvPV" but will force the SV into containing
               just a string ("SvPOK_only").  You want force if
               you are going to update the "SvPVX" directly.

                       char*   SvPV_force(SV* sv, STRLEN len)

       SvPV_force_nomg
               Like "SvPV" but will force the SV into containing
               just a string ("SvPOK_only").  You want force if
               you are going to update the "SvPVX" directly.
               Doesn't process magic.




perl v5.10.1                2010-03-17                         54





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       char*   SvPV_force_nomg(SV* sv, STRLEN len)

       SvPV_nolen
               Returns a pointer to the string in the SV, or a
               stringified form of the SV if the SV does not
               contain a string.  The SV may cache the
               stringified form becoming "SvPOK".  Handles 'get'
               magic.

                       char*   SvPV_nolen(SV* sv)

       SvPV_nomg
               Like "SvPV" but doesn't process magic.

                       char*   SvPV_nomg(SV* sv, STRLEN len)

       SvPV_set
               Set the value of the PV pointer in sv to val.  See
               "SvIV_set".

                       void    SvPV_set(SV* sv, char* val)

       SvREFCNT
               Returns the value of the object's reference count.

                       U32     SvREFCNT(SV* sv)

       SvREFCNT_dec
               Decrements the reference count of the given SV.

                       void    SvREFCNT_dec(SV* sv)

       SvREFCNT_inc
               Increments the reference count of the given SV.

               All of the following SvREFCNT_inc* macros are
               optimized versions of SvREFCNT_inc, and can be
               replaced with SvREFCNT_inc.

                       SV*     SvREFCNT_inc(SV* sv)

       SvREFCNT_inc_NN
               Same as SvREFCNT_inc, but can only be used if you
               know sv is not NULL.  Since we don't have to check
               the NULLness, it's faster and smaller.

                       SV*     SvREFCNT_inc_NN(SV* sv)

       SvREFCNT_inc_simple
               Same as SvREFCNT_inc, but can only be used with
               expressions without side effects.  Since we don't
               have to store a temporary value, it's faster.

                       SV*     SvREFCNT_inc_simple(SV* sv)



perl v5.10.1                2010-03-17                         55





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       SvREFCNT_inc_simple_NN
               Same as SvREFCNT_inc_simple, but can only be used
               if you know sv is not NULL.  Since we don't have
               to check the NULLness, it's faster and smaller.

                       SV*     SvREFCNT_inc_simple_NN(SV* sv)

       SvREFCNT_inc_simple_void
               Same as SvREFCNT_inc_simple, but can only be used
               if you don't need the return value.  The macro
               doesn't need to return a meaningful value.

                       void    SvREFCNT_inc_simple_void(SV* sv)

       SvREFCNT_inc_simple_void_NN
               Same as SvREFCNT_inc, but can only be used if you
               don't need the return value, and you know that sv
               is not NULL.  The macro doesn't need to return a
               meaningful value, or check for NULLness, so it's
               smaller and faster.

                       void    SvREFCNT_inc_simple_void_NN(SV* sv)

       SvREFCNT_inc_void
               Same as SvREFCNT_inc, but can only be used if you
               don't need the return value.  The macro doesn't
               need to return a meaningful value.

                       void    SvREFCNT_inc_void(SV* sv)

       SvREFCNT_inc_void_NN
               Same as SvREFCNT_inc, but can only be used if you
               don't need the return value, and you know that sv
               is not NULL.  The macro doesn't need to return a
               meaningful value, or check for NULLness, so it's
               smaller and faster.

                       void    SvREFCNT_inc_void_NN(SV* sv)

       SvROK   Tests if the SV is an RV.

                       U32     SvROK(SV* sv)

       SvROK_off
               Unsets the RV status of an SV.

                       void    SvROK_off(SV* sv)

       SvROK_on
               Tells an SV that it is an RV.

                       void    SvROK_on(SV* sv)

       SvRV    Dereferences an RV to return the SV.



perl v5.10.1                2010-03-17                         56





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       SV*     SvRV(SV* sv)

       SvRV_set
               Set the value of the RV pointer in sv to val.  See
               "SvIV_set".

                       void    SvRV_set(SV* sv, SV* val)

       SvSTASH Returns the stash of the SV.

                       HV*     SvSTASH(SV* sv)

       SvSTASH_set
               Set the value of the STASH pointer in sv to val.
               See "SvIV_set".

                       void    SvSTASH_set(SV* sv, HV* val)

       SvTAINT Taints an SV if tainting is enabled.

                       void    SvTAINT(SV* sv)

       SvTAINTED
               Checks to see if an SV is tainted. Returns TRUE if
               it is, FALSE if not.

                       bool    SvTAINTED(SV* sv)

       SvTAINTED_off
               Untaints an SV. Be very careful with this routine,
               as it short-circuits some of Perl's fundamental
               security features. XS module authors should not
               use this function unless they fully understand all
               the implications of unconditionally untainting the
               value. Untainting should be done in the standard
               perl fashion, via a carefully crafted regexp,
               rather than directly untainting variables.

                       void    SvTAINTED_off(SV* sv)

       SvTAINTED_on
               Marks an SV as tainted if tainting is enabled.

                       void    SvTAINTED_on(SV* sv)

       SvTRUE  Returns a boolean indicating whether Perl would
               evaluate the SV as true or false.  See SvOK() for
               a defined/undefined test.  Does not handle 'get'
               magic.

                       bool    SvTRUE(SV* sv)

       SvTYPE  Returns the type of the SV.  See "svtype".




perl v5.10.1                2010-03-17                         57





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       svtype  SvTYPE(SV* sv)

       SvUOK   Returns a boolean indicating whether the SV
               contains an unsigned integer.

                       bool    SvUOK(SV* sv)

       SvUPGRADE
               Used to upgrade an SV to a more complex form.
               Uses "sv_upgrade" to perform the upgrade if
               necessary.  See "svtype".

                       void    SvUPGRADE(SV* sv, svtype type)

       SvUTF8  Returns a U32 value indicating whether the SV
               contains UTF-8 encoded data.  Call this after
               SvPV() in case any call to string overloading
               updates the internal flag.

                       U32     SvUTF8(SV* sv)

       SvUTF8_off
               Unsets the UTF-8 status of an SV.

                       void    SvUTF8_off(SV *sv)

       SvUTF8_on
               Turn on the UTF-8 status of an SV (the data is not
               changed, just the flag).  Do not use frivolously.

                       void    SvUTF8_on(SV *sv)

       SvUV    Coerces the given SV to an unsigned integer and
               returns it.  See "SvUVx" for a version which
               guarantees to evaluate sv only once.

                       UV      SvUV(SV* sv)

       SvUVX   Returns the raw value in the SV's UV slot, without
               checks or conversions.  Only use when you are sure
               SvIOK is true. See also "SvUV()".

                       UV      SvUVX(SV* sv)

       SvUVx   Coerces the given SV to an unsigned integer and
               returns it. Guarantees to "sv" only once. Only use
               this if "sv" is an expression with side effects,
               otherwise use the more efficient "SvUV".

                       UV      SvUVx(SV* sv)

       SvUV_nomg
               Like "SvUV" but doesn't process magic.




perl v5.10.1                2010-03-17                         58





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       UV      SvUV_nomg(SV* sv)

       SvUV_set
               Set the value of the UV pointer in sv to val.  See
               "SvIV_set".

                       void    SvUV_set(SV* sv, UV val)

       SvVOK   Returns a boolean indicating whether the SV
               contains a v-string.

                       bool    SvVOK(SV* sv)

       sv_catpvn_nomg
               Like "sv_catpvn" but doesn't process magic.

                       void    sv_catpvn_nomg(SV* sv, const char* ptr, STRLEN len)

       sv_catsv_nomg
               Like "sv_catsv" but doesn't process magic.

                       void    sv_catsv_nomg(SV* dsv, SV* ssv)

       sv_derived_from
               Returns a boolean indicating whether the SV is
               derived from the specified class at the C level.
               To check derivation at the Perl level, call
               "isa()" as a normal Perl method.

                       bool    sv_derived_from(SV* sv, const char* name)

       sv_does Returns a boolean indicating whether the SV
               performs a specific, named role.  The SV can be a
               Perl object or the name of a Perl class.

                       bool    sv_does(SV* sv, const char* name)

       sv_report_used
               Dump the contents of all SVs not yet freed.
               (Debugging aid).

                       void    sv_report_used()

       sv_setsv_nomg
               Like "sv_setsv" but doesn't process magic.

                       void    sv_setsv_nomg(SV* dsv, SV* ssv)

       sv_utf8_upgrade_nomg
               Like sv_utf8_upgrade, but doesn't do magic on "sv"

                       STRLEN  sv_utf8_upgrade_nomg(NN SV *sv)





perl v5.10.1                2010-03-17                         59





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


SV-Body Allocation
       looks_like_number
               Test if the content of an SV looks like a number
               (or is a number).  "Inf" and "Infinity" are
               treated as numbers (so will not issue a non-
               numeric warning), even if your atof() doesn't grok
               them.

                       I32     looks_like_number(SV* sv)

       newRV_noinc
               Creates an RV wrapper for an SV.  The reference
               count for the original SV is not incremented.

                       SV*     newRV_noinc(SV* sv)

       newSV   Creates a new SV.  A non-zero "len" parameter
               indicates the number of bytes of preallocated
               string space the SV should have.  An extra byte
               for a trailing NUL is also reserved.  (SvPOK is
               not set for the SV even if string space is
               allocated.)  The reference count for the new SV is
               set to 1.

               In 5.9.3, newSV() replaces the older NEWSV() API,
               and drops the first parameter, x, a debug aid
               which allowed callers to identify themselves.
               This aid has been superseded by a new build
               option, PERL_MEM_LOG (see "PERL_MEM_LOG" in
               perlhack).  The older API is still there for use
               in XS modules supporting older perls.

                       SV*     newSV(STRLEN len)

       newSVhek
               Creates a new SV from the hash key structure.  It
               will generate scalars that point to the shared
               string table where possible. Returns a new
               (undefined) SV if the hek is NULL.

                       SV*     newSVhek(const HEK *hek)

       newSViv Creates a new SV and copies an integer into it.
               The reference count for the SV is set to 1.

                       SV*     newSViv(IV i)

       newSVnv Creates a new SV and copies a floating point value
               into it.  The reference count for the SV is set to
               1.

                       SV*     newSVnv(NV n)

       newSVpv Creates a new SV and copies a string into it.  The



perl v5.10.1                2010-03-17                         60





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               reference count for the SV is set to 1.  If "len"
               is zero, Perl will compute the length using
               strlen().  For efficiency, consider using
               "newSVpvn" instead.

                       SV*     newSVpv(const char* s, STRLEN len)

       newSVpvf
               Creates a new SV and initializes it with the
               string formatted like "sprintf".

                       SV*     newSVpvf(const char* pat, ...)

       newSVpvn
               Creates a new SV and copies a string into it.  The
               reference count for the SV is set to 1.  Note that
               if "len" is zero, Perl will create a zero length
               string.  You are responsible for ensuring that the
               source string is at least "len" bytes long.  If
               the "s" argument is NULL the new SV will be
               undefined.

                       SV*     newSVpvn(const char* s, STRLEN len)

       newSVpvn_flags
               Creates a new SV and copies a string into it.  The
               reference count for the SV is set to 1.  Note that
               if "len" is zero, Perl will create a zero length
               string.  You are responsible for ensuring that the
               source string is at least "len" bytes long.  If
               the "s" argument is NULL the new SV will be
               undefined.  Currently the only flag bits accepted
               are "SVf_UTF8" and "SVs_TEMP".  If "SVs_TEMP" is
               set, then "sv2mortal()" is called on the result
               before returning. If "SVf_UTF8" is set, then it
               will be set on the new SV.  "newSVpvn_utf8()" is a
               convenience wrapper for this function, defined as

                   #define newSVpvn_utf8(s, len, u)                    \
                       newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)

                       SV*     newSVpvn_flags(const char* s, STRLEN len, U32 flags)

       newSVpvn_share
               Creates a new SV with its SvPVX_const pointing to
               a shared string in the string table. If the string
               does not already exist in the table, it is created
               first.  Turns on READONLY and FAKE. If the "hash"
               parameter is non-zero, that value is used;
               otherwise the hash is computed. The string's hash
               can be later be retrieved from the SV with the
               "SvSHARED_HASH()" macro. The idea here is that as
               the string table is used for shared hash keys
               these strings will have SvPVX_const == HeKEY and



perl v5.10.1                2010-03-17                         61





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               hash lookup will avoid string compare.

                       SV*     newSVpvn_share(const char* s, I32 len, U32 hash)

       newSVpvs
               Like "newSVpvn", but takes a literal string
               instead of a string/length pair.

                       SV*     newSVpvs(const char* s)

       newSVpvs_flags
               Like "newSVpvn_flags", but takes a literal string
               instead of a string/length pair.

                       SV*     newSVpvs_flags(const char* s, U32 flags)

       newSVpvs_share
               Like "newSVpvn_share", but takes a literal string
               instead of a string/length pair and omits the hash
               parameter.

                       SV*     newSVpvs_share(const char* s)

       newSVrv Creates a new SV for the RV, "rv", to point to.
               If "rv" is not an RV then it will be upgraded to
               one.  If "classname" is non-null then the new SV
               will be blessed in the specified package.  The new
               SV is returned and its reference count is 1.

                       SV*     newSVrv(SV* rv, const char* classname)

       newSVsv Creates a new SV which is an exact duplicate of
               the original SV.  (Uses "sv_setsv").

                       SV*     newSVsv(SV* old)

       newSVuv Creates a new SV and copies an unsigned integer
               into it.  The reference count for the SV is set to
               1.

                       SV*     newSVuv(UV u)

       newSV_type
               Creates a new SV, of the type specified.  The
               reference count for the new SV is set to 1.

                       SV*     newSV_type(svtype type)

       sv_2bool
               This function is only called on magical items, and
               is only used by sv_true() or its macro equivalent.

                       bool    sv_2bool(SV* sv)




perl v5.10.1                2010-03-17                         62





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_2cv  Using various gambits, try to get a CV from an SV;
               in addition, try if possible to set *st and *gvp
               to the stash and GV associated with it.  The flags
               in "lref" are passed to sv_fetchsv.

                       CV*     sv_2cv(SV* sv, HV** st, GV** gvp, I32 lref)

       sv_2io  Using various gambits, try to get an IO from an
               SV: the IO slot if its a GV; or the recursive
               result if we're an RV; or the IO slot of the
               symbol named after the PV if we're a string.

                       IO*     sv_2io(SV* sv)

       sv_2iv_flags
               Return the integer value of an SV, doing any
               necessary string conversion.  If flags includes
               SV_GMAGIC, does an mg_get() first.  Normally used
               via the "SvIV(sv)" and "SvIVx(sv)" macros.

                       IV      sv_2iv_flags(SV* sv, I32 flags)

       sv_2mortal
               Marks an existing SV as mortal.  The SV will be
               destroyed "soon", either by an explicit call to
               FREETMPS, or by an implicit call at places such as
               statement boundaries.  SvTEMP() is turned on which
               means that the SV's string buffer can be "stolen"
               if this SV is copied. See also "sv_newmortal" and
               "sv_mortalcopy".

                       SV*     sv_2mortal(SV* sv)

       sv_2nv  Return the num value of an SV, doing any necessary
               string or integer conversion, magic etc. Normally
               used via the "SvNV(sv)" and "SvNVx(sv)" macros.

                       NV      sv_2nv(SV* sv)

       sv_2pvbyte
               Return a pointer to the byte-encoded
               representation of the SV, and set *lp to its
               length.  May cause the SV to be downgraded from
               UTF-8 as a side-effect.

               Usually accessed via the "SvPVbyte" macro.

                       char*   sv_2pvbyte(SV* sv, STRLEN* lp)

       sv_2pvutf8
               Return a pointer to the UTF-8-encoded
               representation of the SV, and set *lp to its
               length.  May cause the SV to be upgraded to UTF-8
               as a side-effect.



perl v5.10.1                2010-03-17                         63





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               Usually accessed via the "SvPVutf8" macro.

                       char*   sv_2pvutf8(SV* sv, STRLEN* lp)

       sv_2pv_flags
               Returns a pointer to the string value of an SV,
               and sets *lp to its length.  If flags includes
               SV_GMAGIC, does an mg_get() first. Coerces sv to a
               string if necessary.  Normally invoked via the
               "SvPV_flags" macro. "sv_2pv()" and "sv_2pv_nomg"
               usually end up here too.

                       char*   sv_2pv_flags(SV* sv, STRLEN* lp, I32 flags)

       sv_2uv_flags
               Return the unsigned integer value of an SV, doing
               any necessary string conversion.  If flags
               includes SV_GMAGIC, does an mg_get() first.
               Normally used via the "SvUV(sv)" and "SvUVx(sv)"
               macros.

                       UV      sv_2uv_flags(SV* sv, I32 flags)

       sv_backoff
               Remove any string offset. You should normally use
               the "SvOOK_off" macro wrapper instead.

                       int     sv_backoff(SV* sv)

       sv_bless
               Blesses an SV into a specified package.  The SV
               must be an RV.  The package must be designated by
               its stash (see "gv_stashpv()").  The reference
               count of the SV is unaffected.

                       SV*     sv_bless(SV* sv, HV* stash)

       sv_catpv
               Concatenates the string onto the end of the string
               which is in the SV.  If the SV has the UTF-8
               status set, then the bytes appended should be
               valid UTF-8.  Handles 'get' magic, but not 'set'
               magic.  See "sv_catpv_mg".

                       void    sv_catpv(SV* sv, const char* ptr)

       sv_catpvf
               Processes its arguments like "sprintf" and appends
               the formatted output to an SV.  If the appended
               data contains "wide" characters (including, but
               not limited to, SVs with a UTF-8 PV formatted with
               %s, and characters >255 formatted with %c), the
               original SV might get upgraded to UTF-8.  Handles
               'get' magic, but not 'set' magic.  See



perl v5.10.1                2010-03-17                         64





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "sv_catpvf_mg". If the original SV was UTF-8, the
               pattern should be valid UTF-8; if the original SV
               was bytes, the pattern should be too.

                       void    sv_catpvf(SV* sv, const char* pat, ...)

       sv_catpvf_mg
               Like "sv_catpvf", but also handles 'set' magic.

                       void    sv_catpvf_mg(SV *sv, const char* pat, ...)

       sv_catpvn
               Concatenates the string onto the end of the string
               which is in the SV.  The "len" indicates number of
               bytes to copy.  If the SV has the UTF-8 status
               set, then the bytes appended should be valid
               UTF-8.  Handles 'get' magic, but not 'set' magic.
               See "sv_catpvn_mg".

                       void    sv_catpvn(SV *dsv, const char *sstr, STRLEN len)

       sv_catpvn_flags
               Concatenates the string onto the end of the string
               which is in the SV.  The "len" indicates number of
               bytes to copy.  If the SV has the UTF-8 status
               set, then the bytes appended should be valid
               UTF-8.  If "flags" has "SV_GMAGIC" bit set, will
               "mg_get" on "dsv" if appropriate, else not.
               "sv_catpvn" and "sv_catpvn_nomg" are implemented
               in terms of this function.

                       void    sv_catpvn_flags(SV *dstr, const char *sstr, STRLEN len, I32 flags)

       sv_catpvs
               Like "sv_catpvn", but takes a literal string
               instead of a string/length pair.

                       void    sv_catpvs(SV* sv, const char* s)

       sv_catpv_mg
               Like "sv_catpv", but also handles 'set' magic.

                       void    sv_catpv_mg(SV *sv, const char *ptr)

       sv_catsv
               Concatenates the string from SV "ssv" onto the end
               of the string in SV "dsv".  Modifies "dsv" but not
               "ssv".  Handles 'get' magic, but not 'set' magic.
               See "sv_catsv_mg".

                       void    sv_catsv(SV *dstr, SV *sstr)

       sv_catsv_flags
               Concatenates the string from SV "ssv" onto the end



perl v5.10.1                2010-03-17                         65





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               of the string in SV "dsv".  Modifies "dsv" but not
               "ssv".  If "flags" has "SV_GMAGIC" bit set, will
               "mg_get" on the SVs if appropriate, else not.
               "sv_catsv" and "sv_catsv_nomg" are implemented in
               terms of this function.

                       void    sv_catsv_flags(SV* dsv, SV* ssv, I32 flags)

       sv_chop Efficient removal of characters from the beginning
               of the string buffer.  SvPOK(sv) must be true and
               the "ptr" must be a pointer to somewhere inside
               the string buffer.  The "ptr" becomes the first
               character of the adjusted string. Uses the "OOK
               hack".  Beware: after this function returns, "ptr"
               and SvPVX_const(sv) may no longer refer to the
               same chunk of data.

                       void    sv_chop(SV* sv, const char* ptr)

       sv_clear
               Clear an SV: call any destructors, free up any
               memory used by the body, and free the body itself.
               The SV's head is not freed, although its type is
               set to all 1's so that it won't inadvertently be
               assumed to be live during global destruction etc.
               This function should only be called when REFCNT is
               zero. Most of the time you'll want to call
               "sv_free()" (or its macro wrapper "SvREFCNT_dec")
               instead.

                       void    sv_clear(SV* sv)

       sv_cmp  Compares the strings in two SVs.  Returns -1, 0,
               or 1 indicating whether the string in "sv1" is
               less than, equal to, or greater than the string in
               "sv2". Is UTF-8 and 'use bytes' aware, handles get
               magic, and will coerce its args to strings if
               necessary.  See also "sv_cmp_locale".

                       I32     sv_cmp(SV* sv1, SV* sv2)

       sv_cmp_locale
               Compares the strings in two SVs in a locale-aware
               manner. Is UTF-8 and 'use bytes' aware, handles
               get magic, and will coerce its args to strings if
               necessary.  See also "sv_cmp".

                       I32     sv_cmp_locale(SV* sv1, SV* sv2)

       sv_collxfrm
               Add Collate Transform magic to an SV if it doesn't
               already have it.

               Any scalar variable may carry PERL_MAGIC_collxfrm



perl v5.10.1                2010-03-17                         66





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               magic that contains the scalar data of the
               variable, but transformed to such a format that a
               normal memory comparison can be used to compare
               the data according to the locale settings.

                       char*   sv_collxfrm(SV* sv, STRLEN* nxp)

       sv_copypv
               Copies a stringified representation of the source
               SV into the destination SV.  Automatically
               performs any necessary mg_get and coercion of
               numeric values into strings.  Guaranteed to
               preserve UTF8 flag even from overloaded objects.
               Similar in nature to sv_2pv[_flags] but operates
               directly on an SV instead of just the string.
               Mostly uses sv_2pv_flags to do its work, except
               when that would lose the UTF-8'ness of the PV.

                       void    sv_copypv(SV* dsv, SV* ssv)

       sv_dec  Auto-decrement of the value in the SV, doing
               string to numeric conversion if necessary. Handles
               'get' magic.

                       void    sv_dec(SV* sv)

       sv_eq   Returns a boolean indicating whether the strings
               in the two SVs are identical. Is UTF-8 and 'use
               bytes' aware, handles get magic, and will coerce
               its args to strings if necessary.

                       I32     sv_eq(SV* sv1, SV* sv2)

       sv_force_normal_flags
               Undo various types of fakery on an SV: if the PV
               is a shared string, make a private copy; if we're
               a ref, stop refing; if we're a glob, downgrade to
               an xpvmg; if we're a copy-on-write scalar, this is
               the on-write time when we do the copy, and is also
               used locally. If "SV_COW_DROP_PV" is set then a
               copy-on-write scalar drops its PV buffer (if any)
               and becomes SvPOK_off rather than making a copy.
               (Used where this scalar is about to be set to some
               other value.) In addition, the "flags" parameter
               gets passed to "sv_unref_flags()" when unrefing.
               "sv_force_normal" calls this function with flags
               set to 0.

                       void    sv_force_normal_flags(SV *sv, U32 flags)

       sv_free Decrement an SV's reference count, and if it drops
               to zero, call "sv_clear" to invoke destructors and
               free up any memory used by the body; finally,
               deallocate the SV's head itself.  Normally called



perl v5.10.1                2010-03-17                         67





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               via a wrapper macro "SvREFCNT_dec".

                       void    sv_free(SV* sv)

       sv_gets Get a line from the filehandle and store it into
               the SV, optionally appending to the currently-
               stored string.

                       char*   sv_gets(SV* sv, PerlIO* fp, I32 append)

       sv_grow Expands the character buffer in the SV.  If
               necessary, uses "sv_unref" and upgrades the SV to
               "SVt_PV".  Returns a pointer to the character
               buffer.  Use the "SvGROW" wrapper instead.

                       char*   sv_grow(SV* sv, STRLEN newlen)

       sv_inc  Auto-increment of the value in the SV, doing
               string to numeric conversion if necessary. Handles
               'get' magic.

                       void    sv_inc(SV* sv)

       sv_insert
               Inserts a string at the specified offset/length
               within the SV. Similar to the Perl substr()
               function. Handles get magic.

                       void    sv_insert(SV *bigstr, STRLEN offset, STRLEN len, const char *little, STRLEN littlelen)

       sv_insert_flags
               Same as "sv_insert", but the extra "flags" are
               passed the "SvPV_force_flags" that applies to
               "bigstr".

                       void    sv_insert_flags(SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen, const U32 flags)

       sv_isa  Returns a boolean indicating whether the SV is
               blessed into the specified class.  This does not
               check for subtypes; use "sv_derived_from" to
               verify an inheritance relationship.

                       int     sv_isa(SV* sv, const char* name)

       sv_isobject
               Returns a boolean indicating whether the SV is an
               RV pointing to a blessed object.  If the SV is not
               an RV, or if the object is not blessed, then this
               will return false.

                       int     sv_isobject(SV* sv)

       sv_len  Returns the length of the string in the SV.
               Handles magic and type coercion.  See also



perl v5.10.1                2010-03-17                         68





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "SvCUR", which gives raw access to the xpv_cur
               slot.

                       STRLEN  sv_len(SV* sv)

       sv_len_utf8
               Returns the number of characters in the string in
               an SV, counting wide UTF-8 bytes as a single
               character. Handles magic and type coercion.

                       STRLEN  sv_len_utf8(SV* sv)

       sv_magic
               Adds magic to an SV. First upgrades "sv" to type
               "SVt_PVMG" if necessary, then adds a new magic
               item of type "how" to the head of the magic list.

               See "sv_magicext" (which "sv_magic" now calls) for
               a description of the handling of the "name" and
               "namlen" arguments.

               You need to use "sv_magicext" to add magic to
               SvREADONLY SVs and also to add more than one
               instance of the same 'how'.

                       void    sv_magic(SV* sv, SV* obj, int how, const char* name, I32 namlen)

       sv_magicext
               Adds magic to an SV, upgrading it if necessary.
               Applies the supplied vtable and returns a pointer
               to the magic added.

               Note that "sv_magicext" will allow things that
               "sv_magic" will not.  In particular, you can add
               magic to SvREADONLY SVs, and add more than one
               instance of the same 'how'.

               If "namlen" is greater than zero then a "savepvn"
               copy of "name" is stored, if "namlen" is zero then
               "name" is stored as-is and - as another special
               case - if "(name && namlen == HEf_SVKEY)" then
               "name" is assumed to contain an "SV*" and is
               stored as-is with its REFCNT incremented.

               (This is now used as a subroutine by "sv_magic".)

                       MAGIC * sv_magicext(SV* sv, SV* obj, int how, const MGVTBL *vtbl, const char* name, I32 namlen)

       sv_mortalcopy
               Creates a new SV which is a copy of the original
               SV (using "sv_setsv").  The new SV is marked as
               mortal. It will be destroyed "soon", either by an
               explicit call to FREETMPS, or by an implicit call
               at places such as statement boundaries.  See also



perl v5.10.1                2010-03-17                         69





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "sv_newmortal" and "sv_2mortal".

                       SV*     sv_mortalcopy(SV* oldsv)

       sv_newmortal
               Creates a new null SV which is mortal.  The
               reference count of the SV is set to 1. It will be
               destroyed "soon", either by an explicit call to
               FREETMPS, or by an implicit call at places such as
               statement boundaries.  See also "sv_mortalcopy"
               and "sv_2mortal".

                       SV*     sv_newmortal()

       sv_newref
               Increment an SV's reference count. Use the
               "SvREFCNT_inc()" wrapper instead.

                       SV*     sv_newref(SV* sv)

       sv_pos_b2u
               Converts the value pointed to by offsetp from a
               count of bytes from the start of the string, to a
               count of the equivalent number of UTF-8 chars.
               Handles magic and type coercion.

                       void    sv_pos_b2u(SV* sv, I32* offsetp)

       sv_pos_u2b
               Converts the value pointed to by offsetp from a
               count of UTF-8 chars from the start of the string,
               to a count of the equivalent number of bytes; if
               lenp is non-zero, it does the same to lenp, but
               this time starting from the offset, rather than
               from the start of the string. Handles magic and
               type coercion.

                       void    sv_pos_u2b(SV* sv, I32* offsetp, I32* lenp)

       sv_pvbyten_force
               The backend for the "SvPVbytex_force" macro.
               Always use the macro instead.

                       char*   sv_pvbyten_force(SV* sv, STRLEN* lp)

       sv_pvn_force
               Get a sensible string out of the SV somehow.  A
               private implementation of the "SvPV_force" macro
               for compilers which can't cope with complex macro
               expressions. Always use the macro instead.

                       char*   sv_pvn_force(SV* sv, STRLEN* lp)





perl v5.10.1                2010-03-17                         70





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_pvn_force_flags
               Get a sensible string out of the SV somehow.  If
               "flags" has "SV_GMAGIC" bit set, will "mg_get" on
               "sv" if appropriate, else not. "sv_pvn_force" and
               "sv_pvn_force_nomg" are implemented in terms of
               this function.  You normally want to use the
               various wrapper macros instead: see "SvPV_force"
               and "SvPV_force_nomg"

                       char*   sv_pvn_force_flags(SV* sv, STRLEN* lp, I32 flags)

       sv_pvutf8n_force
               The backend for the "SvPVutf8x_force" macro.
               Always use the macro instead.

                       char*   sv_pvutf8n_force(SV* sv, STRLEN* lp)

       sv_reftype
               Returns a string describing what the SV is a
               reference to.

                       const char*     sv_reftype(const SV* sv, int ob)

       sv_replace
               Make the first argument a copy of the second, then
               delete the original.  The target SV physically
               takes over ownership of the body of the source SV
               and inherits its flags; however, the target keeps
               any magic it owns, and any magic in the source is
               discarded.  Note that this is a rather specialist
               SV copying operation; most of the time you'll want
               to use "sv_setsv" or one of its many macro front-
               ends.

                       void    sv_replace(SV* sv, SV* nsv)

       sv_reset
               Underlying implementation for the "reset" Perl
               function.  Note that the perl-level function is
               vaguely deprecated.

                       void    sv_reset(const char* s, HV* stash)

       sv_rvweaken
               Weaken a reference: set the "SvWEAKREF" flag on
               this RV; give the referred-to SV
               "PERL_MAGIC_backref" magic if it hasn't already;
               and push a back-reference to this RV onto the
               array of backreferences associated with that
               magic. If the RV is magical, set magic will be
               called after the RV is cleared.

                       SV*     sv_rvweaken(SV *sv)




perl v5.10.1                2010-03-17                         71





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_setiv
               Copies an integer into the given SV, upgrading
               first if necessary.  Does not handle 'set' magic.
               See also "sv_setiv_mg".

                       void    sv_setiv(SV* sv, IV num)

       sv_setiv_mg
               Like "sv_setiv", but also handles 'set' magic.

                       void    sv_setiv_mg(SV *sv, IV i)

       sv_setnv
               Copies a double into the given SV, upgrading first
               if necessary.  Does not handle 'set' magic.  See
               also "sv_setnv_mg".

                       void    sv_setnv(SV* sv, NV num)

       sv_setnv_mg
               Like "sv_setnv", but also handles 'set' magic.

                       void    sv_setnv_mg(SV *sv, NV num)

       sv_setpv
               Copies a string into an SV.  The string must be
               null-terminated.  Does not handle 'set' magic.
               See "sv_setpv_mg".

                       void    sv_setpv(SV* sv, const char* ptr)

       sv_setpvf
               Works like "sv_catpvf" but copies the text into
               the SV instead of appending it.  Does not handle
               'set' magic.  See "sv_setpvf_mg".

                       void    sv_setpvf(SV* sv, const char* pat, ...)

       sv_setpvf_mg
               Like "sv_setpvf", but also handles 'set' magic.

                       void    sv_setpvf_mg(SV *sv, const char* pat, ...)

       sv_setpviv
               Copies an integer into the given SV, also updating
               its string value.  Does not handle 'set' magic.
               See "sv_setpviv_mg".

                       void    sv_setpviv(SV* sv, IV num)

       sv_setpviv_mg
               Like "sv_setpviv", but also handles 'set' magic.

                       void    sv_setpviv_mg(SV *sv, IV iv)



perl v5.10.1                2010-03-17                         72





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_setpvn
               Copies a string into an SV.  The "len" parameter
               indicates the number of bytes to be copied.  If
               the "ptr" argument is NULL the SV will become
               undefined.  Does not handle 'set' magic.  See
               "sv_setpvn_mg".

                       void    sv_setpvn(SV* sv, const char* ptr, STRLEN len)

       sv_setpvn_mg
               Like "sv_setpvn", but also handles 'set' magic.

                       void    sv_setpvn_mg(SV *sv, const char *ptr, STRLEN len)

       sv_setpvs
               Like "sv_setpvn", but takes a literal string
               instead of a string/length pair.

                       void    sv_setpvs(SV* sv, const char* s)

       sv_setpv_mg
               Like "sv_setpv", but also handles 'set' magic.

                       void    sv_setpv_mg(SV *sv, const char *ptr)

       sv_setref_iv
               Copies an integer into a new SV, optionally
               blessing the SV.  The "rv" argument will be
               upgraded to an RV.  That RV will be modified to
               point to the new SV.  The "classname" argument
               indicates the package for the blessing.  Set
               "classname" to "NULL" to avoid the blessing.  The
               new SV will have a reference count of 1, and the
               RV will be returned.

                       SV*     sv_setref_iv(SV* rv, const char* classname, IV iv)

       sv_setref_nv
               Copies a double into a new SV, optionally blessing
               the SV.  The "rv" argument will be upgraded to an
               RV.  That RV will be modified to point to the new
               SV.  The "classname" argument indicates the
               package for the blessing.  Set "classname" to
               "NULL" to avoid the blessing.  The new SV will
               have a reference count of 1, and the RV will be
               returned.

                       SV*     sv_setref_nv(SV* rv, const char* classname, NV nv)

       sv_setref_pv
               Copies a pointer into a new SV, optionally
               blessing the SV.  The "rv" argument will be
               upgraded to an RV.  That RV will be modified to
               point to the new SV.  If the "pv" argument is NULL



perl v5.10.1                2010-03-17                         73





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               then "PL_sv_undef" will be placed into the SV.
               The "classname" argument indicates the package for
               the blessing.  Set "classname" to "NULL" to avoid
               the blessing.  The new SV will have a reference
               count of 1, and the RV will be returned.

               Do not use with other Perl types such as HV, AV,
               SV, CV, because those objects will become
               corrupted by the pointer copy process.

               Note that "sv_setref_pvn" copies the string while
               this copies the pointer.

                       SV*     sv_setref_pv(SV* rv, const char* classname, void* pv)

       sv_setref_pvn
               Copies a string into a new SV, optionally blessing
               the SV.  The length of the string must be
               specified with "n".  The "rv" argument will be
               upgraded to an RV.  That RV will be modified to
               point to the new SV.  The "classname" argument
               indicates the package for the blessing.  Set
               "classname" to "NULL" to avoid the blessing.  The
               new SV will have a reference count of 1, and the
               RV will be returned.

               Note that "sv_setref_pv" copies the pointer while
               this copies the string.

                       SV*     sv_setref_pvn(SV* rv, const char* classname, const char* pv, STRLEN n)

       sv_setref_uv
               Copies an unsigned integer into a new SV,
               optionally blessing the SV.  The "rv" argument
               will be upgraded to an RV.  That RV will be
               modified to point to the new SV.  The "classname"
               argument indicates the package for the blessing.
               Set "classname" to "NULL" to avoid the blessing.
               The new SV will have a reference count of 1, and
               the RV will be returned.

                       SV*     sv_setref_uv(SV* rv, const char* classname, UV uv)

       sv_setsv
               Copies the contents of the source SV "ssv" into
               the destination SV "dsv".  The source SV may be
               destroyed if it is mortal, so don't use this
               function if the source SV needs to be reused. Does
               not handle 'set' magic.  Loosely speaking, it
               performs a copy-by-value, obliterating any
               previous content of the destination.

               You probably want to use one of the assortment of
               wrappers, such as "SvSetSV", "SvSetSV_nosteal",



perl v5.10.1                2010-03-17                         74





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               "SvSetMagicSV" and "SvSetMagicSV_nosteal".

                       void    sv_setsv(SV *dstr, SV *sstr)

       sv_setsv_flags
               Copies the contents of the source SV "ssv" into
               the destination SV "dsv".  The source SV may be
               destroyed if it is mortal, so don't use this
               function if the source SV needs to be reused. Does
               not handle 'set' magic.  Loosely speaking, it
               performs a copy-by-value, obliterating any
               previous content of the destination.  If the
               "flags" parameter has the "SV_GMAGIC" bit set,
               will "mg_get" on "ssv" if appropriate, else not.
               If the "flags" parameter has the "NOSTEAL" bit set
               then the buffers of temps will not be stolen.
               <sv_setsv> and "sv_setsv_nomg" are implemented in
               terms of this function.

               You probably want to use one of the assortment of
               wrappers, such as "SvSetSV", "SvSetSV_nosteal",
               "SvSetMagicSV" and "SvSetMagicSV_nosteal".

               This is the primary function for copying scalars,
               and most other copy-ish functions and macros use
               this underneath.

                       void    sv_setsv_flags(SV *dstr, SV *sstr, I32 flags)

       sv_setsv_mg
               Like "sv_setsv", but also handles 'set' magic.

                       void    sv_setsv_mg(SV *dstr, SV *sstr)

       sv_setuv
               Copies an unsigned integer into the given SV,
               upgrading first if necessary.  Does not handle
               'set' magic.  See also "sv_setuv_mg".

                       void    sv_setuv(SV* sv, UV num)

       sv_setuv_mg
               Like "sv_setuv", but also handles 'set' magic.

                       void    sv_setuv_mg(SV *sv, UV u)

       sv_tainted
               Test an SV for taintedness. Use "SvTAINTED"
               instead.       bool sv_tainted(SV* sv)

       sv_true Returns true if the SV has a true value by Perl's
               rules.  Use the "SvTRUE" macro instead, which may
               call "sv_true()" or may instead use an in-line
               version.



perl v5.10.1                2010-03-17                         75





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       I32     sv_true(SV *sv)

       sv_unmagic
               Removes all magic of type "type" from an SV.

                       int     sv_unmagic(SV* sv, int type)

       sv_unref_flags
               Unsets the RV status of the SV, and decrements the
               reference count of whatever was being referenced
               by the RV.  This can almost be thought of as a
               reversal of "newSVrv".  The "cflags" argument can
               contain "SV_IMMEDIATE_UNREF" to force the
               reference count to be decremented (otherwise the
               decrementing is conditional on the reference count
               being different from one or the reference being a
               readonly SV).  See "SvROK_off".

                       void    sv_unref_flags(SV *ref, U32 flags)

       sv_untaint
               Untaint an SV. Use "SvTAINTED_off" instead.
                    void sv_untaint(SV* sv)

       sv_upgrade
               Upgrade an SV to a more complex form.  Generally
               adds a new body type to the SV, then copies across
               as much information as possible from the old body.
               You generally want to use the "SvUPGRADE" macro
               wrapper. See also "svtype".

                       void    sv_upgrade(SV* sv, svtype new_type)

       sv_usepvn_flags
               Tells an SV to use "ptr" to find its string value.
               Normally the string is stored inside the SV but
               sv_usepvn allows the SV to use an outside string.
               The "ptr" should point to memory that was
               allocated by "malloc".  The string length, "len",
               must be supplied.  By default this function will
               realloc (i.e. move) the memory pointed to by
               "ptr", so that pointer should not be freed or used
               by the programmer after giving it to sv_usepvn,
               and neither should any pointers from "behind" that
               pointer (e.g. ptr + 1) be used.

               If "flags" & SV_SMAGIC is true, will call
               SvSETMAGIC. If "flags" & SV_HAS_TRAILING_NUL is
               true, then "ptr[len]" must be NUL, and the realloc
               will be skipped. (i.e. the buffer is actually at
               least 1 byte longer than "len", and already meets
               the requirements for storing in "SvPVX")

                       void    sv_usepvn_flags(SV* sv, char* ptr, STRLEN len, U32 flags)



perl v5.10.1                2010-03-17                         76





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       sv_utf8_decode
               If the PV of the SV is an octet sequence in UTF-8
               and contains a multiple-byte character, the
               "SvUTF8" flag is turned on so that it looks like a
               character. If the PV contains only single-byte
               characters, the "SvUTF8" flag stays being off.
               Scans PV for validity and returns false if the PV
               is invalid UTF-8.

               NOTE: this function is experimental and may change
               or be removed without notice.

                       bool    sv_utf8_decode(SV *sv)

       sv_utf8_downgrade
               Attempts to convert the PV of an SV from
               characters to bytes.  If the PV contains a
               character that cannot fit in a byte, this
               conversion will fail; in this case, either returns
               false or, if "fail_ok" is not true, croaks.

               This is not as a general purpose Unicode to byte
               encoding interface: use the Encode extension for
               that.

               NOTE: this function is experimental and may change
               or be removed without notice.

                       bool    sv_utf8_downgrade(SV *sv, bool fail_ok)

       sv_utf8_encode
               Converts the PV of an SV to UTF-8, but then turns
               the "SvUTF8" flag off so that it looks like octets
               again.

                       void    sv_utf8_encode(SV *sv)

       sv_utf8_upgrade
               Converts the PV of an SV to its UTF-8-encoded
               form.  Forces the SV to string form if it is not
               already.  Will "mg_get" on "sv" if appropriate.
               Always sets the SvUTF8 flag to avoid future
               validity checks even if the whole string is the
               same in UTF-8 as not.  Returns the number of bytes
               in the converted string

               This is not as a general purpose byte encoding to
               Unicode interface: use the Encode extension for
               that.

                       STRLEN  sv_utf8_upgrade(SV *sv)

       sv_utf8_upgrade_flags
               Converts the PV of an SV to its UTF-8-encoded



perl v5.10.1                2010-03-17                         77





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               form.  Forces the SV to string form if it is not
               already.  Always sets the SvUTF8 flag to avoid
               future validity checks even if all the bytes are
               invariant in UTF-8. If "flags" has "SV_GMAGIC" bit
               set, will "mg_get" on "sv" if appropriate, else
               not.  Returns the number of bytes in the converted
               string "sv_utf8_upgrade" and
               "sv_utf8_upgrade_nomg" are implemented in terms of
               this function.

               This is not as a general purpose byte encoding to
               Unicode interface: use the Encode extension for
               that.

                       STRLEN  sv_utf8_upgrade_flags(SV *sv, I32 flags)

       sv_utf8_upgrade_nomg
               Like sv_utf8_upgrade, but doesn't do magic on "sv"

                       STRLEN  sv_utf8_upgrade_nomg(SV *sv)

       sv_vcatpvf
               Processes its arguments like "vsprintf" and
               appends the formatted output to an SV.  Does not
               handle 'set' magic.  See "sv_vcatpvf_mg".

               Usually used via its frontend "sv_catpvf".

                       void    sv_vcatpvf(SV* sv, const char* pat, va_list* args)

       sv_vcatpvfn
               Processes its arguments like "vsprintf" and
               appends the formatted output to an SV.  Uses an
               array of SVs if the C style variable argument list
               is missing (NULL).  When running with taint checks
               enabled, indicates via "maybe_tainted" if results
               are untrustworthy (often due to the use of
               locales).

               Usually used via one of its frontends "sv_vcatpvf"
               and "sv_vcatpvf_mg".

                       void    sv_vcatpvfn(SV* sv, const char* pat, STRLEN patlen, va_list* args, SV** svargs, I32 svmax, bool *maybe_tainted)

       sv_vcatpvf_mg
               Like "sv_vcatpvf", but also handles 'set' magic.

               Usually used via its frontend "sv_catpvf_mg".

                       void    sv_vcatpvf_mg(SV* sv, const char* pat, va_list* args)

       sv_vsetpvf
               Works like "sv_vcatpvf" but copies the text into
               the SV instead of appending it.  Does not handle



perl v5.10.1                2010-03-17                         78





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               'set' magic.  See "sv_vsetpvf_mg".

               Usually used via its frontend "sv_setpvf".

                       void    sv_vsetpvf(SV* sv, const char* pat, va_list* args)

       sv_vsetpvfn
               Works like "sv_vcatpvfn" but copies the text into
               the SV instead of appending it.

               Usually used via one of its frontends "sv_vsetpvf"
               and "sv_vsetpvf_mg".

                       void    sv_vsetpvfn(SV* sv, const char* pat, STRLEN patlen, va_list* args, SV** svargs, I32 svmax, bool *maybe_tainted)

       sv_vsetpvf_mg
               Like "sv_vsetpvf", but also handles 'set' magic.

               Usually used via its frontend "sv_setpvf_mg".

                       void    sv_vsetpvf_mg(SV* sv, const char* pat, va_list* args)

Unicode Support
       bytes_from_utf8
               Converts a string "s" of length "len" from UTF-8
               into native byte encoding.  Unlike "utf8_to_bytes"
               but like "bytes_to_utf8", returns a pointer to the
               newly-created string, and updates "len" to contain
               the new length.  Returns the original string if no
               conversion occurs, "len" is unchanged. Do nothing
               if "is_utf8" points to 0. Sets "is_utf8" to 0 if
               "s" is converted or consisted entirely of
               characters that are invariant in utf8 (i.e., US-
               ASCII on non-EBCDIC machines).

               NOTE: this function is experimental and may change
               or be removed without notice.

                       U8*     bytes_from_utf8(const U8 *s, STRLEN *len, bool *is_utf8)

       bytes_to_utf8
               Converts a string "s" of length "len" from the
               native encoding into UTF-8.  Returns a pointer to
               the newly-created string, and sets "len" to
               reflect the new length.

               A NUL character will be written after the end of
               the string.

               If you want to convert to UTF-8 from encodings
               other than the native (Latin1 or EBCDIC), see
               sv_recode_to_utf8().

               NOTE: this function is experimental and may change



perl v5.10.1                2010-03-17                         79





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               or be removed without notice.

                       U8*     bytes_to_utf8(const U8 *s, STRLEN *len)

       ibcmp_utf8
               Return true if the strings s1 and s2 differ case-
               insensitively, false if not (if they are equal
               case-insensitively).  If u1 is true, the string s1
               is assumed to be in UTF-8-encoded Unicode.  If u2
               is true, the string s2 is assumed to be in
               UTF-8-encoded Unicode.  If u1 or u2 are false, the
               respective string is assumed to be in native 8-bit
               encoding.

               If the pe1 and pe2 are non-NULL, the scanning
               pointers will be copied in there (they will point
               at the beginning of the next character).  If the
               pointers behind pe1 or pe2 are non-NULL, they are
               the end pointers beyond which scanning will not
               continue under any circumstances.  If the byte
               lengths l1 and l2 are non-zero, s1+l1 and s2+l2
               will be used as goal end pointers that will also
               stop the scan, and which qualify towards defining
               a successful match: all the scans that define an
               explicit length must reach their goal pointers for
               a match to succeed).

               For case-insensitiveness, the "casefolding" of
               Unicode is used instead of upper/lowercasing both
               the characters, see
               http://www.unicode.org/unicode/reports/tr21/ (Case
               Mappings).

                       I32     ibcmp_utf8(const char *s1, char **pe1, UV l1, bool u1, const char *s2, char **pe2, UV l2, bool u2)

       is_utf8_char
               Tests if some arbitrary number of bytes begins in
               a valid UTF-8 character.  Note that an INVARIANT
               (i.e. ASCII on non-EBCDIC machines) character is a
               valid UTF-8 character.  The actual number of bytes
               in the UTF-8 character will be returned if it is
               valid, otherwise 0.

                       STRLEN  is_utf8_char(const U8 *s)

       is_utf8_string
               Returns true if first "len" bytes of the given
               string form a valid UTF-8 string, false otherwise.
               Note that 'a valid UTF-8 string' does not mean 'a
               string that contains code points above 0x7F
               encoded in UTF-8' because a valid ASCII string is
               a valid UTF-8 string.

               See also is_utf8_string_loclen() and



perl v5.10.1                2010-03-17                         80





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               is_utf8_string_loc().

                       bool    is_utf8_string(const U8 *s, STRLEN len)

       is_utf8_string_loc
               Like is_utf8_string() but stores the location of
               the failure (in the case of "utf8ness failure") or
               the location s+len (in the case of "utf8ness
               success") in the "ep".

               See also is_utf8_string_loclen() and
               is_utf8_string().

                       bool    is_utf8_string_loc(const U8 *s, STRLEN len, const U8 **p)

       is_utf8_string_loclen
               Like is_utf8_string() but stores the location of
               the failure (in the case of "utf8ness failure") or
               the location s+len (in the case of "utf8ness
               success") in the "ep", and the number of UTF-8
               encoded characters in the "el".

               See also is_utf8_string_loc() and
               is_utf8_string().

                       bool    is_utf8_string_loclen(const U8 *s, STRLEN len, const U8 **ep, STRLEN *el)

       pv_uni_display
               Build to the scalar dsv a displayable version of
               the string spv, length len, the displayable
               version being at most pvlim bytes long (if longer,
               the rest is truncated and "..." will be appended).

               The flags argument can have UNI_DISPLAY_ISPRINT
               set to display isPRINT()able characters as
               themselves, UNI_DISPLAY_BACKSLASH to display the
               \\[nrfta\\] as the backslashed versions (like
               '\n') (UNI_DISPLAY_BACKSLASH is preferred over
               UNI_DISPLAY_ISPRINT for \\).  UNI_DISPLAY_QQ (and
               its alias UNI_DISPLAY_REGEX) have both
               UNI_DISPLAY_BACKSLASH and UNI_DISPLAY_ISPRINT
               turned on.

               The pointer to the PV of the dsv is returned.

                       char*   pv_uni_display(SV *dsv, const U8 *spv, STRLEN len, STRLEN pvlim, UV flags)

       sv_cat_decode
               The encoding is assumed to be an Encode object,
               the PV of the ssv is assumed to be octets in that
               encoding and decoding the input starts from the
               position which (PV + *offset) pointed to.  The dsv
               will be concatenated the decoded UTF-8 string from
               ssv.  Decoding will terminate when the string tstr



perl v5.10.1                2010-03-17                         81





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               appears in decoding output or the input ends on
               the PV of the ssv. The value which the offset
               points will be modified to the last input position
               on the ssv.

               Returns TRUE if the terminator was found, else
               returns FALSE.

                       bool    sv_cat_decode(SV* dsv, SV *encoding, SV *ssv, int *offset, char* tstr, int tlen)

       sv_recode_to_utf8
               The encoding is assumed to be an Encode object, on
               entry the PV of the sv is assumed to be octets in
               that encoding, and the sv will be converted into
               Unicode (and UTF-8).

               If the sv already is UTF-8 (or if it is not POK),
               or if the encoding is not a reference, nothing is
               done to the sv.  If the encoding is not an
               "Encode::XS" Encoding object, bad things will
               happen.  (See lib/encoding.pm and Encode).

               The PV of the sv is returned.

                       char*   sv_recode_to_utf8(SV* sv, SV *encoding)

       sv_uni_display
               Build to the scalar dsv a displayable version of
               the scalar sv, the displayable version being at
               most pvlim bytes long (if longer, the rest is
               truncated and "..." will be appended).

               The flags argument is as in pv_uni_display().

               The pointer to the PV of the dsv is returned.

                       char*   sv_uni_display(SV *dsv, SV *ssv, STRLEN pvlim, UV flags)

       to_utf8_case
               The "p" contains the pointer to the UTF-8 string
               encoding the character that is being converted.

               The "ustrp" is a pointer to the character buffer
               to put the conversion result to.  The "lenp" is a
               pointer to the length of the result.

               The "swashp" is a pointer to the swash to use.

               Both the special and normal mappings are stored
               lib/unicore/To/Foo.pl, and loaded by SWASHNEW,
               using lib/utf8_heavy.pl.  The special (usually,
               but not always, a multicharacter mapping), is
               tried first.




perl v5.10.1                2010-03-17                         82





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               The "special" is a string like
               "utf8::ToSpecLower", which means the hash
               %utf8::ToSpecLower.  The access to the hash is
               through Perl_to_utf8_case().

               The "normal" is a string like "ToLower" which
               means the swash %utf8::ToLower.

                       UV      to_utf8_case(const U8 *p, U8* ustrp, STRLEN *lenp, SV **swashp, const char *normal, const char *special)

       to_utf8_fold
               Convert the UTF-8 encoded character at p to its
               foldcase version and store that in UTF-8 in ustrp
               and its length in bytes in lenp.  Note that the
               ustrp needs to be at least UTF8_MAXBYTES_CASE+1
               bytes since the foldcase version may be longer
               than the original character (up to three
               characters).

               The first character of the foldcased version is
               returned (but note, as explained above, that there
               may be more.)

                       UV      to_utf8_fold(const U8 *p, U8* ustrp, STRLEN *lenp)

       to_utf8_lower
               Convert the UTF-8 encoded character at p to its
               lowercase version and store that in UTF-8 in ustrp
               and its length in bytes in lenp.  Note that the
               ustrp needs to be at least UTF8_MAXBYTES_CASE+1
               bytes since the lowercase version may be longer
               than the original character.

               The first character of the lowercased version is
               returned (but note, as explained above, that there
               may be more.)

                       UV      to_utf8_lower(const U8 *p, U8* ustrp, STRLEN *lenp)

       to_utf8_title
               Convert the UTF-8 encoded character at p to its
               titlecase version and store that in UTF-8 in ustrp
               and its length in bytes in lenp.  Note that the
               ustrp needs to be at least UTF8_MAXBYTES_CASE+1
               bytes since the titlecase version may be longer
               than the original character.

               The first character of the titlecased version is
               returned (but note, as explained above, that there
               may be more.)

                       UV      to_utf8_title(const U8 *p, U8* ustrp, STRLEN *lenp)





perl v5.10.1                2010-03-17                         83





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       to_utf8_upper
               Convert the UTF-8 encoded character at p to its
               uppercase version and store that in UTF-8 in ustrp
               and its length in bytes in lenp.  Note that the
               ustrp needs to be at least UTF8_MAXBYTES_CASE+1
               bytes since the uppercase version may be longer
               than the original character.

               The first character of the uppercased version is
               returned (but note, as explained above, that there
               may be more.)

                       UV      to_utf8_upper(const U8 *p, U8* ustrp, STRLEN *lenp)

       utf8n_to_uvchr
               flags

               Returns the native character value of the first
               character in the string "s" which is assumed to be
               in UTF-8 encoding; "retlen" will be set to the
               length, in bytes, of that character.

               Allows length and flags to be passed to low level
               routine.

                       UV      utf8n_to_uvchr(const U8 *s, STRLEN curlen, STRLEN *retlen, U32 flags)

       utf8n_to_uvuni
               Bottom level UTF-8 decode routine.  Returns the
               Unicode code point value of the first character in
               the string "s" which is assumed to be in UTF-8
               encoding and no longer than "curlen"; "retlen"
               will be set to the length, in bytes, of that
               character.

               If "s" does not point to a well-formed UTF-8
               character, the behaviour is dependent on the value
               of "flags": if it contains UTF8_CHECK_ONLY, it is
               assumed that the caller will raise a warning, and
               this function will silently just set "retlen" to
               "-1" and return zero.  If the "flags" does not
               contain UTF8_CHECK_ONLY, warnings about
               malformations will be given, "retlen" will be set
               to the expected length of the UTF-8 character in
               bytes, and zero will be returned.

               The "flags" can also contain various flags to
               allow deviations from the strict UTF-8 encoding
               (see utf8.h).

               Most code should use utf8_to_uvchr() rather than
               call this directly.

                       UV      utf8n_to_uvuni(const U8 *s, STRLEN curlen, STRLEN *retlen, U32 flags)



perl v5.10.1                2010-03-17                         84





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


       utf8_distance
               Returns the number of UTF-8 characters between the
               UTF-8 pointers "a" and "b".

               WARNING: use only if you *know* that the pointers
               point inside the same UTF-8 buffer.

                       IV      utf8_distance(const U8 *a, const U8 *b)

       utf8_hop
               Return the UTF-8 pointer "s" displaced by "off"
               characters, either forward or backward.

               WARNING: do not use the following unless you
               *know* "off" is within the UTF-8 data pointed to
               by "s" *and* that on entry "s" is aligned on the
               first byte of character or just after the last
               byte of a character.

                       U8*     utf8_hop(const U8 *s, I32 off)

       utf8_length
               Return the length of the UTF-8 char encoded string
               "s" in characters.  Stops at "e" (inclusive).  If
               "e < s" or if the scan would end up past "e",
               croaks.

                       STRLEN  utf8_length(const U8* s, const U8 *e)

       utf8_to_bytes
               Converts a string "s" of length "len" from UTF-8
               into native byte encoding.  Unlike
               "bytes_to_utf8", this over-writes the original
               string, and updates len to contain the new length.
               Returns zero on failure, setting "len" to -1.

               If you need a copy of the string, see
               "bytes_from_utf8".

               NOTE: this function is experimental and may change
               or be removed without notice.

                       U8*     utf8_to_bytes(U8 *s, STRLEN *len)

       utf8_to_uvchr
               Returns the native character value of the first
               character in the string "s" which is assumed to be
               in UTF-8 encoding; "retlen" will be set to the
               length, in bytes, of that character.

               If "s" does not point to a well-formed UTF-8
               character, zero is returned and retlen is set, if
               possible, to -1.




perl v5.10.1                2010-03-17                         85





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                       UV      utf8_to_uvchr(const U8 *s, STRLEN *retlen)

       utf8_to_uvuni
               Returns the Unicode code point of the first
               character in the string "s" which is assumed to be
               in UTF-8 encoding; "retlen" will be set to the
               length, in bytes, of that character.

               This function should only be used when the
               returned UV is considered an index into the
               Unicode semantic tables (e.g. swashes).

               If "s" does not point to a well-formed UTF-8
               character, zero is returned and retlen is set, if
               possible, to -1.

                       UV      utf8_to_uvuni(const U8 *s, STRLEN *retlen)

       uvchr_to_utf8
               Adds the UTF-8 representation of the Native
               codepoint "uv" to the end of the string "d"; "d"
               should be have at least "UTF8_MAXBYTES+1" free
               bytes available. The return value is the pointer
               to the byte after the end of the new character. In
               other words,

                   d = uvchr_to_utf8(d, uv);

               is the recommended wide native character-aware way
               of saying

                   *(d++) = uv;

                       U8*     uvchr_to_utf8(U8 *d, UV uv)

       uvuni_to_utf8_flags
               Adds the UTF-8 representation of the Unicode
               codepoint "uv" to the end of the string "d"; "d"
               should be have at least "UTF8_MAXBYTES+1" free
               bytes available. The return value is the pointer
               to the byte after the end of the new character. In
               other words,

                   d = uvuni_to_utf8_flags(d, uv, flags);

               or, in most cases,

                   d = uvuni_to_utf8(d, uv);

               (which is equivalent to)

                   d = uvuni_to_utf8_flags(d, uv, 0);

               is the recommended Unicode-aware way of saying



perl v5.10.1                2010-03-17                         86





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                   *(d++) = uv;

                       U8*     uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)

Variables created by "xsubpp" and "xsubpp" internal functions
       ax      Variable which is setup by "xsubpp" to indicate
               the stack base offset, used by the "ST",
               "XSprePUSH" and "XSRETURN" macros.  The "dMARK"
               macro must be called prior to setup the "MARK"
               variable.

                       I32     ax

       CLASS   Variable which is setup by "xsubpp" to indicate
               the class name for a C++ XS constructor.  This is
               always a "char*".  See "THIS".

                       char*   CLASS

       dAX     Sets up the "ax" variable.  This is usually
               handled automatically by "xsubpp" by calling
               "dXSARGS".

                               dAX;

       dAXMARK Sets up the "ax" variable and stack marker
               variable "mark".  This is usually handled
               automatically by "xsubpp" by calling "dXSARGS".

                               dAXMARK;

       dITEMS  Sets up the "items" variable.  This is usually
               handled automatically by "xsubpp" by calling
               "dXSARGS".

                               dITEMS;

       dUNDERBAR
               Sets up the "padoff_du" variable for an XSUB that
               wishes to use "UNDERBAR".

                               dUNDERBAR;

       dXSARGS Sets up stack and mark pointers for an XSUB,
               calling dSP and dMARK.  Sets up the "ax" and
               "items" variables by calling "dAX" and "dITEMS".
               This is usually handled automatically by "xsubpp".

                               dXSARGS;

       dXSI32  Sets up the "ix" variable for an XSUB which has
               aliases.  This is usually handled automatically by
               "xsubpp".




perl v5.10.1                2010-03-17                         87





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


                               dXSI32;

       items   Variable which is setup by "xsubpp" to indicate
               the number of items on the stack.  See "Variable-
               length Parameter Lists" in perlxs.

                       I32     items

       ix      Variable which is setup by "xsubpp" to indicate
               which of an XSUB's aliases was used to invoke it.
               See "The ALIAS: Keyword" in perlxs.

                       I32     ix

       newXSproto
               Used by "xsubpp" to hook up XSUBs as Perl subs.
               Adds Perl prototypes to the subs.

       RETVAL  Variable which is setup by "xsubpp" to hold the
               return value for an XSUB. This is always the
               proper type for the XSUB. See "The RETVAL
               Variable" in perlxs.

                       (whatever)      RETVAL

       ST      Used to access elements on the XSUB's stack.

                       SV*     ST(int ix)

       THIS    Variable which is setup by "xsubpp" to designate
               the object in a C++ XSUB.  This is always the
               proper type for the C++ object.  See "CLASS" and
               "Using XS With C++" in perlxs.

                       (whatever)      THIS

       UNDERBAR
               The SV* corresponding to the $_ variable. Works
               even if there is a lexical $_ in scope.

       XS      Macro to declare an XSUB and its C parameter list.
               This is handled by "xsubpp".

       XS_VERSION
               The version identifier for an XS module.  This is
               usually handled automatically by
               "ExtUtils::MakeMaker".  See
               "XS_VERSION_BOOTCHECK".

       XS_VERSION_BOOTCHECK
               Macro to verify that a PM module's $VERSION
               variable matches the XS module's "XS_VERSION"
               variable.  This is usually handled automatically
               by "xsubpp".  See "The VERSIONCHECK: Keyword" in



perl v5.10.1                2010-03-17                         88





PERLAPI(1)       Perl Programmers Reference Guide      PERLAPI(1)


               perlxs.

                               XS_VERSION_BOOTCHECK;

Warning and Dieing
       croak   This is the XSUB-writer's interface to Perl's
               "die" function.  Normally call this function the
               same way you call the C "printf" function.
               Calling "croak" returns control directly to Perl,
               sidestepping the normal C order of execution. See
               "warn".

               If you want to throw an exception object, assign
               the object to $@ and then pass "NULL" to croak():

                  errsv = get_sv("@", GV_ADD);
                  sv_setsv(errsv, exception_object);
                  croak(NULL);

                       void    croak(const char* pat, ...)

       warn    This is the XSUB-writer's interface to Perl's
               "warn" function.  Call this function the same way
               you call the C "printf" function.  See "croak".

                       void    warn(const char* pat, ...)

AUTHORS
       Until May 1997, this document was maintained by Jeff
       Okamoto <okamoto@corp.hp.com>.  It is now maintained as
       part of Perl itself.

       With lots of help and suggestions from Dean Roehrich,
       Malcolm Beattie, Andreas Koenig, Paul Hudson, Ilya
       Zakharevich, Paul Marquess, Neil Bowers, Matthew Green,
       Tim Bunce, Spider Boardman, Ulrich Pfeifer, Stephen
       McCamant, and Gurusamy Sarathy.

       API Listing originally by Dean Roehrich
       <roehrich@cray.com>.

       Updated to be autogenerated from comments in the source by
       Benjamin Stuhl.

SEE ALSO
       perlguts(1), perlxs(1), perlxstut(1), perlintern(1)











perl v5.10.1                2010-03-17                         89


