lib(3)
NAME
lib - manipulate @INC at compile time
SYNOPSIS
use lib LIST; no lib LIST;
DESCRIPTION
This is a small simple module which simplifies the manipu
lation 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 mod
ule also checks to see if a directory called $dir/$arch
name/auto exists. If so the $dir/$archname directory is
assumed to be a corresponding architecture specific direc
tory 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
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 mod
ule also checks to see if a directory called $dir/$arch
name/auto exists. If so the $dir/$archname directory is
assumed to be a corresponding architecture specific direc
tory 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 Unixstyle or Mac-style paths work, and Unix-style paths are
converted properly to Mac-style paths before being added
to @INC).
SEE ALSO
FindBin - optional module which deals with paths relative
to the source file.
AUTHOR
- Tim Bunce, 2nd June 1995.