


B::Lint(3p)      Perl Programmers Reference Guide     B::Lint(3p)


NAME
       B::Lint - Perl lint

SYNOPSIS
       perl -MO=Lint[,OPTIONS] foo.pl

DESCRIPTION
       The B::Lint module is equivalent to an extended version of
       the -w option of perl. It is named after the program lint
       which carries out a similar process for C programs.

OPTIONS AND LINT CHECKS
       Option words are separated by commas (not whitespace) and
       follow the usual conventions of compiler backend options.
       Following any options (indicated by a leading -) come lint
       check arguments. Each such argument (apart from the spe-
       cial all and none options) is a word representing one pos-
       sible lint check (turning on that check) or is no-foo
       (turning off that check). Before processing the check
       arguments, a standard list of checks is turned on. Later
       options override earlier ones. Available options are:

       context Produces a warning whenever an array is used in an
               implicit scalar context. For example, both of the
               lines

                   $foo = length(@bar);
                   $foo = @bar;
               will elicit a warning. Using an explicit B<scalar()> silences the
               warning. For example,

                   $foo = scalar(@bar);


       implicit-read and implicit-write
               These options produce a warning whenever an opera-
               tion implicitly reads or (respectively) writes to
               one of Perl's special variables.  For example,
               implicit-read will warn about these:

                   /foo/;

               and implicit-write will warn about these:

                   s/foo/bar/;

               Both implicit-read and implicit-write warn about
               this:

                   for (@a) { ... }


       dollar-underscore
               This option warns whenever $_ is used either



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B::Lint(3p)      Perl Programmers Reference Guide     B::Lint(3p)


               explicitly anywhere or as the implicit argument of
               a print statement.

       private-names
               This option warns on each use of any variable,
               subroutine or method name that lives in a non-cur-
               rent package but begins with an underscore ("_").
               Warnings aren't issued for the special case of the
               single character name "_" by itself (e.g. $_ and
               @_).

       undefined-subs
               This option warns whenever an undefined subroutine
               is invoked.  This option will only catch explic-
               itly invoked subroutines such as "foo()" and not
               indirect invocations such as "&$subref()" or
               "$obj->meth()". Note that some programs or modules
               delay definition of subs until runtime by means of
               the AUTOLOAD mechanism.

       regexp-variables
               This option warns whenever one of the regexp vari-
               ables $', $& or $' is used. Any occurrence of any
               of these variables in your program can slow your
               whole program down. See the perlre manpage for
               details.

       all     Turn all warnings on.

       none    Turn all warnings off.

NON LINT-CHECK OPTIONS
       -u Package
               Normally, Lint only checks the main code of the
               program together with all subs defined in package
               main. The -u option lets you include other package
               names whose subs are then checked by Lint.

BUGS
       This is only a very preliminary version.

AUTHOR
       Malcolm Beattie, mbeattie@sable.ox.ac.uk.














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