phpman > man > lib(3pm)

NAME
    lib - manipulate @INC at compile time

SYNOPSIS
        use lib LIST;

        no lib LIST;

DESCRIPTION
    This is a small simple module which simplifies the manipulation of @INC at compile time.

    It is typically used to add extra directories to perl's search path so that later "use" or
    "require" statements will find modules which are not located on perl's default search path.

  Adding directories to @INC
    The parameters to "use lib" are added to the start of the perl search path. Saying

        use lib LIST;

    is *almost* the same as saying

        BEGIN { unshift(@INC, LIST) }

    For each directory in LIST (called $dir here) the lib module also checks to see if a directory
    called $dir/$archname/auto exists. If so the $dir/$archname directory is assumed to be a
    corresponding architecture specific directory and is added to @INC in front of $dir. lib.pm also
    checks if directories called $dir/$version and $dir/$version/$archname exist and adds these
    directories to @INC.

    The current value of $archname can be found with this command:

        perl -V:archname

    The corresponding command to get the current value of $version is:

        perl -V:version

    To avoid memory leaks, all trailing duplicate entries in @INC are removed.

  Deleting directories from @INC
    You should normally only add directories to @INC. If you need to delete directories from @INC
    take care to only delete those which you added yourself or which you are certain are not needed
    by other modules in your script. Other modules may have added directories which they need for
    correct operation.

    The "no lib" statement deletes all instances of each named directory from @INC.

    For each directory in LIST (called $dir here) the lib module also checks to see if a directory
    called $dir/$archname/auto exists. If so the $dir/$archname directory is assumed to be a
    corresponding architecture specific directory and is also deleted from @INC. lib.pm also checks
    if directories called $dir/$version and $dir/$version/$archname exist and deletes these
    directories from @INC.

  Restoring original @INC
    When the lib module is first loaded it records the current value of @INC in an array
    @lib::ORIG_INC. To restore @INC to that value you can say

        @INC = @lib::ORIG_INC;

CAVEATS
    In order to keep lib.pm small and simple, it only works with Unix filepaths. This doesn't mean
    it only works on Unix, but non-Unix users must first translate their file paths to Unix
    conventions.

        # VMS users wanting to put [.stuff.moo] into
        # their @INC would write
        use lib 'stuff/moo';

NOTES
    In the future, this module will likely use File::Spec for determining paths, as it does now for
    Mac OS (where Unix-style or Mac-style paths work, and Unix-style paths are converted properly to
    Mac-style paths before being added to @INC).

    If you try to add a file to @INC as follows:

      use lib 'this_is_a_file.txt';

    "lib" will warn about this. The sole exceptions are files with the ".par" extension which are
    intended to be used as libraries.

SEE ALSO
    FindBin - optional module which deals with paths relative to the source file.

    PAR - optional module which can treat ".par" files as Perl libraries.

AUTHOR
    Tim Bunce, 2nd June 1995.

    "lib" is maintained by the perl5-porters. Please direct any questions to the canonical mailing
    list. Anything that is applicable to the CPAN release can be sent to its maintainer, though.

    Maintainer: The Perl5-Porters <perl5-porters AT perl.org>

    Maintainer of the CPAN release: Steffen Mueller <smueller AT cpan.org>

COPYRIGHT AND LICENSE
    This package has been part of the perl core since perl 5.001. It has been released separately to
    CPAN so older installations can benefit from bug fixes.

    This package has the same copyright and license as the perl core.