NAME

lib::relative - Add paths relative to the current file to @INC

SYNOPSIS

# Path is relative to this file, not current working directory
use lib::relative 'path/to/lib';
use lib::relative '../../lib';

# Add two lib paths, as in lib.pm
use lib::relative 'foo', 'bar';

# Absolute paths are passed through unchanged
use lib::relative 'foo/baz', '/path/to/lib';

# Equivalent code using core modules
use Cwd ();
use File::Basename ();
use File::Spec ();
use lib File::Spec->catdir(File::Basename::dirname(Cwd::abs_path __FILE__), 'path/to/lib');

DESCRIPTION

Adding a path to @INC to load modules from a local directory may seem
simple, but has a few common pitfalls to be aware of. Directly adding a
relative path to @INC means that any later code that changes the
current working directory will change where modules are loaded from.
This applies to the . path that used to be in @INC by default until
perl 5.26.0, or a relative path added in code like use lib
'path/to/lib', and may be a vulnerability if such a location is not
supposed to be writable. Additionally, the commonly used FindBin module
relies on interpreter state and the path to the original script invoked
by the perl interpreter, sometimes requiring workarounds in uncommon
cases like generated or embedded code. This module proposes a more
straightforward method: take a path relative to the current file,
absolutize it, and add it to @INC.

If this module is already available to be loaded, it can be used as
with lib.pm, passing relative paths, which will be absolutized relative
to the current file then passed on to lib. Multiple arguments will be
separately absolutized, and absolute paths will be passed on unchanged.

For cases where this module cannot be loaded beforehand, the last
section of the "SYNOPSIS" can be copy-pasted into a file to perform the

CAVEATS

Due to __FILE__ possibly being a path relative to the current working
directory, be sure to use lib::relative or the equivalent code from
"SYNOPSIS" as early as possible in the file. If a chdir occurs before
this code, it will add the incorrect directory path.

All file paths are expected to be in a format appropriate to the
current operating system, e.g. ..\\foo\\bar on Windows. "catdir" in
File::Spec can be used to form directory paths portably.

BUGS

Report any issues on the public bugtracker.

AUTHOR

Dan Book <dbook@cpan.org>