MirBSD manpage: lib(3p)
lib(3p) Perl Programmers Reference Guide lib(3p)
lib - manipulate @INC at compile time
use lib LIST;
no lib LIST;
This is a small simple module which simplifies the manipula-
tion 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.
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 cer-
tain 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
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lib(3p) Perl Programmers Reference Guide lib(3p)
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;
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';
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 con-
verted properly to Mac-style paths before being added to
@INC).
FindBin - optional module which deals with paths relative to
the source file.
Tim Bunce, 2nd June 1995.
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