ylib - Add paths to @INC from a config file


version 0.003


  # in .mylib file
  # from the command line
  $ perl -Mylib -E 'say for @INC'


The ylib module adds paths to @INC from a configuration file named .mylib in which each line represents a library path. The .mylib file can be either in the current directory and/or in the user's home directory. It is equivalent to calling 'use lib' on each path.

Note: ylib will issue a warning if a path in .mylib can't be found.


Occasionally, it's useful to customize @INC on a per-directory basis without changing the global PERL5LIB environment variable. For example, when developing or testing code that requires uninstalled code in an adjacent directory, one could create a .mylib file that adds the necessary path.

For example, consider this directory tree with two Perl distributions, Foo-Bar and Baz-Bam:


The code in Foo-Bar depends on code in Baz-Bam. So in Foo-Bar, create a .mylib file with the appropriate path:

  $ cd Foo-Bar
  $ echo '../Baz-Bam/lib' > .mylib
  $ perl -Mylib Build.PL
  $ Build && Build test

That's easier and shorter than using PERL5LIB on the command line, and it scales better as the number of libraries increases.

In the example above, the Build script preserve @INC including the effect of -Mylib when it was created. This is not the case with Makefile.PL or prove, in which case, PERL5OPT might be an alternative approach for using -Mylib:

  $ export PERL5OPT=-Mylib
  $ prove


Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker at You will be notified automatically of any progress on your issue.

Source Code

This is open source software. The code repository is available for public review and contribution under the terms of the license.

  git clone


David Golden <>


This software is Copyright (c) 2014 by David Golden.

This is free software, licensed under:

  The Apache License, Version 2.0, January 2004