FindBin(3pm) Perl Programmers Reference Guide FindBin(3pm)NAME
FindBin - Locate directory of original perl script
SYNOPSIS
use FindBin;
use lib "$FindBin::Bin/../lib";
or
use FindBin qw($Bin);
use lib "$Bin/../lib";
DESCRIPTION
Locates the full path to the script bin directory to allow the use of paths relative to the bin directory.
This allows a user to setup a directory tree for some software with directories <root>/bin and <root>/lib and then the above example will
allow the use of modules in the lib directory without knowing where the software tree is installed.
If perl is invoked using the -e option or the perl script is read from "STDIN" then FindBin sets both $Bin and $RealBin to the current
directory.
EXPORTABLE VARIABLES
$Bin - path to bin directory from where script was invoked
$Script - basename of script from which perl was invoked
$RealBin - $Bin with all links resolved
$RealScript - $Script with all links resolved
KNOWN ISSUES
If there are two modules using "FindBin" from different directories under the same interpreter, this won't work. Since "FindBin" uses
"BEGIN" block, it'll be executed only once, and only the first caller will get it right. This is a problem under mod_perl and other persis-
tent Perl environments, where you shouldn't use this module. Which also means that you should avoid using "FindBin" in modules that you
plan to put on CPAN. The only way to make sure that "FindBin" will work is to force the "BEGIN" block to be executed again:
delete $INC{'FindBin.pm'};
require FindBin;
KNOWN BUGS
If perl is invoked as
perl filename
and filename does not have executable rights and a program called filename exists in the users $ENV{PATH} which satisfies both -x and -T
then FindBin assumes that it was invoked via the $ENV{PATH}.
Workaround is to invoke perl as
perl ./filename
AUTHORS
FindBin is supported as part of the core perl distribution. Please send bug reports to <perlbug@perl.org> using the perlbug program
included with perl.
Graham Barr <gbarr@pobox.com> Nick Ing-Simmons <nik@tiuk.ti.com>
COPYRIGHT
Copyright (c) 1995 Graham Barr & Nick Ing-Simmons. All rights reserved. This program is free software; you can redistribute it and/or mod-
ify it under the same terms as Perl itself.
perl v5.8.0 2002-06-01 FindBin(3pm)
Check Out this Related Man Page
Find::Lib(3pm) User Contributed Perl Documentation Find::Lib(3pm)NAME
Find::Lib - Helper to smartly find libs to use in the filesystem tree
VERSION
Version 1.01
SYNOPSIS
#!/usr/bin/perl -w;
use strict;
## simple usage
use Find::Lib '../mylib';
## more libraries
use Find::Lib '../mylib', 'local-lib';
## More verbose and backward compatible with Find::Lib < 1.0
use Find::Lib libs => [ 'lib', '../lib', 'devlib' ];
## resolve some path with minimum typing
$dir = Find::Lib->catdir("..", "data");
$path = Find::Lib->catfile("..", "data", "test.yaml");
$base = Find::Lib->base;
# or
$base = Find::Lib::Base;
DESCRIPTION
The purpose of this module is to replace
use FindBin;
use lib "$FindBin::Bin/../bootstrap/lib";
with something shorter. This is specially useful if your project has a lot of scripts (For instance tests scripts).
use Find::Lib '../bootstrap/lib';
The important differences between FindBin and Find::Lib are:
o symlinks and '..'
If you have symlinks in your path it respects them, so basically you can forget you have symlinks, because Find::Lib will do the
natural thing (NOT ignore them), and resolve '..' correctly. FindBin breaks if you do:
use lib "$Bin/../lib";
and you currently are in a symlinked directory, because $Bin resolved to the filesystem path (without the symlink) and not the shell
path.
o convenience
it's faster too type, and more intuitive (Exporting $Bin always felt weird to me).
DISCUSSION
Installation and availability of this module
The usefulness of this module is seriously reduced if Find::Lib is not already in your @INC / $ENV{PERL5LIB} -- Chicken and egg problem.
This is the big disavantage of FindBin over Find::Lib: FindBin is distributed with Perl. To mitigate that, you need to be sure of global
availability of the module in the system (You could install it via your favorite package managment system for instance).
modification of $0 and chdir (BEGIN blocks, other 'use')
As soon as Find::Lib is compiled it saves the location of the script and the initial cwd (current working directory), which are the two
pieces of information the module relies on to interpret the relative path given by the calling program.
If one of cwd, $ENV{PWD} or $0 is changed before Find::Lib has a chance to do its job, then Find::Lib will most probably die, saying "The
script cannot be found". I don't know a workaround that. So be sure to load Find::Lib as soon as possible in your script to minimize
problems (you are in control!).
(some programs alter $0 to customize the display line of the process in the system process-list ("ps" on unix).
(Note, see perlvar for explanation of $0)
USAGE
import
All the work is done in import. So you need to 'use Find::Lib' and pass a list of paths to add to @INC. See "BACKWARD COMPATIBILITY"
section for more retails on this topic.
The paths given are (should) be relative to the location of the current script. The paths won't be added unless the path actually exists
on disk
base
Returns the detected base (the directory where the script lives in). It's a string, and is the same as $Find::Lib::Base.
catfile
A shorcut to File::Spec::catfile using Find::Lib's base.
catdir
A shorcut to File::Spec::catdir using Find::Lib's base.
BACKWARD COMPATIBILITY
in versions <1.0 of Find::Lib, the import arguments allowed you to specify a Bootstrap package. This option is now removed breaking
backward compatibility. I'm sorry about that, but that was a dumb idea of mine to save more typing. But it saves, like, 3 characters at the
expense of readability. So, I'm sure I didn't break anybody, because probabaly no one was relying on a stupid behaviour.
However, the multiple libs argument passing is kept intact: you can still use:
use Find::Lib libs => [ 'a', 'b', 'c' ];
where "libs" is a reference to a list of path to add to @INC.
The short forms implies that the first argument passed to import is not "libs" or "pkgs". An example of usage is given in the SYNOPSIS
section.
SEE ALSO
FindBin, FindBin::libs, lib, rlib, local::lib http://blog.cyberion.net/2009/10/ive-done-something-bad-i-broke-backward-compatibility.html
<http://blog.cyberion.net/2009/10/ive-done-something-bad-i-broke-backward-compatibility.html>
AUTHOR
Yann Kerherve, "<yann.kerherve at gmail.com>"
BUGS
Please report any bugs or feature requests to "bug-find-lib at rt.cpan.org", or through the web interface at
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Find-Lib <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Find-Lib>. I will be notified, and
then you'll automatically be notified of progress on your bug as I make changes.
ACKNOWLEDGEMENT
Six Apart hackers nourrished the discussion that led to this module creation.
Jonathan Steinert (hachi) for doing all the conception of 0.03 shell expansion mode with me.
SUPPORT &; CRITICS
I welcome feedback about this module, don't hesitate to contact me regarding this module, usage or code.
You can find documentation for this module with the perldoc command.
perldoc Find::Lib
You can also look for information at:
o AnnoCPAN: Annotated CPAN documentation
http://annocpan.org/dist/Find-Lib <http://annocpan.org/dist/Find-Lib>
o CPAN Ratings
http://cpanratings.perl.org/d/Find-Lib <http://cpanratings.perl.org/d/Find-Lib>
o RT: CPAN's request tracker
http://rt.cpan.org/NoAuth/Bugs.html?Find-Lib <http://rt.cpan.org/NoAuth/Bugs.html?Find-Lib>
o Search CPAN
http://search.cpan.org/dist/Find-Lib <http://search.cpan.org/dist/Find-Lib>
COPYRIGHT &; LICENSE
Copyright 2007, 2009 Yann Kerherve, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl v5.12.4 2011-09-17 Find::Lib(3pm)