Programming Perl, 4th Edition

blib

From the command line:

% perl –Mblib program [args...]
% perl –Mblib=DIR program [args...]

From your Perl program:

use blib;
use blib DIR;

This pragma is primarily intended as a way to test arbitrary Perl programs against an uninstalled version of a package using Perl’s –M command-line switch. It assumes your directory structure was produced by the standard ExtUtils::MakeMaker or Module::Build modules.

The pragma looks for a blib directory structure starting in the directory named DIR (or current directory if none was specified), and if it doesn’t find a blib directory there, works its way back up through your .. directories, scanning up to five levels of parent directory.