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lib(3pm)                              Perl Programmers Reference Guide                              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.

   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 Macstyle
       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@perl.org>

       Maintainer of the CPAN release: Steffen Mueller <smueller@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.



perl v5.16.2                                     2013-08-25                                         lib(3pm)