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FindBin

Section: Perl Programmers Reference Guide (3)
Updated: 2001-09-21
Index Return to Main Contents
 

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 a "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 persistent 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. To make sure that "FindBin" will work is to call the "again" function:

  use FindBin;
  FindBin::again(); # or FindBin->again;

In former versions of FindBin there was no "again" function. The workaround was 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 modify it under the same terms as Perl itself.


 

Index

NAME
SYNOPSIS
DESCRIPTION
EXPORTABLE VARIABLES
KNOWN ISSUES
KNOWN BUGS
AUTHORS
COPYRIGHT




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