


term(5)                                                   term(5)


NAME
       term - format of compiled term file.

SYNOPSIS
       term

DESCRIPTION
   STORAGE LOCATION
       Compiled terminfo descriptions are placed under the direc-
       tory  /usr/share/misc/terminfo.   Two  configurations  are
       supported (when building the ncurses libraries):

       directory tree
            A  two-level  scheme is used to avoid a linear search
            of a huge UNIX system directory: /usr/share/misc/ter-
            minfo/c/name  where name is the name of the terminal,
            and c is the first character of name.  Thus, act4 can
            be found in the file /usr/share/misc/terminfo/a/act4.
            Synonyms for the same  terminal  are  implemented  by
            multiple links to the same compiled file.

       hashed database
            Using  Berkeley  database,  two  types of records are
            stored: the terminfo  data  in  the  same  format  as
            stored  in  a directory tree with the terminfo's pri-
            mary name as  a  key,  and  records  containing  only
            aliases pointing to the primary name.

            If built to write hashed databases, ncurses can still
            read terminfo  databases  organized  as  a  directory
            tree,  but  cannot  write  entries into the directory
            tree.  It can  write  (or  rewrite)  entries  in  the
            hashed database.

            ncurses  distinguishes  the two cases in the TERMINFO
            and TERMINFO_DIRS environment variable by assuming  a
            directory  tree  for  entries  that  correspond to an
            existing directory, and hashed database otherwise.

   STORAGE FORMAT
       The format has been chosen so that it will be the same  on
       all  hardware.   An  8 or more bit byte is assumed, but no
       assumptions about byte  ordering  or  sign  extension  are
       made.

       The  compiled  file  is  created with the tic program, and
       read by the routine setupterm.  The file is  divided  into
       six parts: the header, terminal names, boolean flags, num-
       bers, strings, and string table.

       The header section begins the file.  This section contains
       six  short  integers in the format described below.  These
       integers are




                                                                1





term(5)                                                   term(5)


            (1) the magic number (octal 0432);

            (2) the size, in bytes, of the names section;

            (3) the number of bytes in the boolean section;

            (4) the number of short integers in the numbers sec-
            tion;

            (5)  the  number  of offsets (short integers) in the
            strings sec- tion;

            (6) the size, in bytes, of the string table.

       Short  integers  are stored in two 8-bit bytes.  The first
       byte contains the least significant 8 bits of  the  value,
       and  the second byte contains the most significant 8 bits.
       (Thus, the value represented  is  256*second+first.)   The
       value -1 is represented by the two bytes 0377, 0377; other
       negative values are illegal. This  value  generally  means
       that  the  corresponding  capability  is missing from this
       terminal.  Note that this format corresponds to the  hard-
       ware  of  the  VAX  and  PDP-11  (that  is,  little-endian
       machines).  Machines where this does not correspond to the
       hardware  must  read the integers as two bytes and compute
       the little-endian value.

       The terminal names section comes next.   It  contains  the
       first  line of the terminfo description, listing the vari-
       ous names for the terminal, separated by the  `|'  charac-
       ter.   The section is terminated with an ASCII NUL charac-
       ter.

       The boolean flags have one byte for each flag.  This  byte
       is  either  0  or 1 if the flag is present or absent.  The
       capabilities are in the same order as the file <term.h>.

       Between the boolean section and the number section, a null
       byte  will  be  inserted, if necessary, to ensure that the
       number section begins on an even byte (this is a relic  of
       the   PDP-11's   word-addressed  architecture,  originally
       designed in to avoid IOT traps  induced  by  addressing  a
       word  on  an  odd  byte boundary).  All short integers are
       aligned on a short word boundary.

       The numbers section is similar to the flags section.  Each
       capability  takes up two bytes, and is stored as a little-
       endian short integer.  If the value represented is -1, the
       capability is taken to be missing.

       The  strings  section is also similar.  Each capability is
       stored as a short integer, in the format above.   A  value
       of  -1  means  the  capability is missing.  Otherwise, the
       value is taken as an offset  from  the  beginning  of  the



                                                                2





term(5)                                                   term(5)


       string table.  Special characters in ^X or \c notation are
       stored in their interpreted form, not the printing  repre-
       sentation.  Padding information $<nn> and parameter infor-
       mation %x are stored intact in uninterpreted form.

       The final section is the string table.   It  contains  all
       the values of string capabilities referenced in the string
       section.  Each string is null terminated.

   EXTENDED STORAGE FORMAT
       The previous section describes the  conventional  terminfo
       binary  format.  With some minor variations of the offsets
       (see PORTABILITY), the same binary format is used  in  all
       modern UNIX systems.  Each system uses a predefined set of
       boolean, number or string capabilities.

       The ncurses libraries and  applications  support  extended
       terminfo binary format, allowing users to define capabili-
       ties which are loaded at runtime.  This extension is  made
       possible  by using the fact that the other implementations
       stop reading the terminfo data when they have reached  the
       end  of  the size given in the header.  ncurses checks the
       size, and if it exceeds that due to the  predefined  data,
       continues to parse according to its own scheme.

       First, it reads the extended header (5 short integers):

            (1)  count of extended boolean capabilities

            (2)  count of extended numeric capabilities

            (3)  count of extended string capabilities

            (4)  size of the extended string table in bytes.

            (5)  last  offset  of  the  extended  string table in
                 bytes.

       Using the counts and sizes, ncurses allocates  arrays  and
       reads  data for the extended capabilties in the same order
       as the header information.

       The extended string table contains values for string capa-
       bilities.   After the end of these values, it contains the
       names for each of  the  extended  capabilities  in  order,
       e.g., booleans, then numbers and finally strings.

PORTABILITY
       Note that it is possible for setupterm to expect a differ-
       ent set of capabilities than are actually present  in  the
       file.   Either  the  database  may have been updated since
       setupterm was recompiled (resulting in extra  unrecognized
       entries  in  the file) or the program may have been recom-
       piled  more  recently  than  the  database   was   updated



                                                                3





term(5)                                                   term(5)


       (resulting  in  missing  entries).   The routine setupterm
       must be prepared for both possibilities - this is why  the
       numbers  and  sizes  are included.  Also, new capabilities
       must always be added at the end of the lists  of  boolean,
       number, and string capabilities.

       Despite  the  consistent  use of little-endian for numbers
       and the otherwise self-describing format, it is  not  wise
       to count on portability of binary terminfo entries between
       commercial UNIX versions.  The problem is that  there  are
       at least three versions of terminfo (under HP-UX, AIX, and
       OSF/1) which diverged from System V terminfo  after  SVr1,
       and  have added extension capabilities to the string table
       that (in the binary format) collide with System V and  XSI
       Curses  extensions.   See terminfo(5) for detailed discus-
       sion of terminfo source compatibility issues.

EXAMPLE
       As an example, here is a hex dump of the  description  for
       the  Lear-Siegler  ADM-3,  a  popular though rather stupid
       early terminal:

       adm3a|lsi adm3a,
               am,
               cols#80, lines#24,
               bel=^G, clear= 32$<1>, cr=^M, cub1=^H, cud1=^J,
               cuf1=^L, cup=\E=%p1%{32}%+%c%p2%{32}%+%c, cuu1=^K,
               home=^^, ind=^J,

       0000  1a 01 10 00 02 00 03 00  82 00 31 00 61 64 6d 33  ........ ..1.adm3
       0010  61 7c 6c 73 69 20 61 64  6d 33 61 00 00 01 50 00  a|lsi ad m3a...P.
       0020  ff ff 18 00 ff ff 00 00  02 00 ff ff ff ff 04 00  ........ ........
       0030  ff ff ff ff ff ff ff ff  0a 00 25 00 27 00 ff ff  ........ ..%.'...
       0040  29 00 ff ff ff ff 2b 00  ff ff 2d 00 ff ff ff ff  ).....+. ..-.....
       0050  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0060  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0070  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0080  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0090  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       00a0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       00b0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       00c0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       00d0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       00e0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       00f0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0100  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0110  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ........ ........
       0120  ff ff ff ff ff ff 2f 00  07 00 0d 00 1a 24 3c 31  ....../. .....$<1
       0130  3e 00 1b 3d 25 70 31 25  7b 33 32 7d 25 2b 25 63  >..=%p1% {32}%+%c
       0140  25 70 32 25 7b 33 32 7d  25 2b 25 63 00 0a 00 1e  %p2%{32} %+%c....
       0150  00 08 00 0c 00 0b 00 0a  00                       ........ .






                                                                4





term(5)                                                   term(5)


LIMITS
       Some limitations: total  compiled  entries  cannot  exceed
       4096 bytes.  The name field cannot exceed 128 bytes.

FILES
       /usr/share/misc/terminfo/?/*  compiled terminal capability
       database

SEE ALSO
       curses(3), terminfo(5).

AUTHORS
       Thomas E. Dickey
       extended terminfo format for ncurses 5.0
       hashed database support for ncurses 5.6

       Eric S. Raymond








































                                                                5


