freebsd-dev/contrib/perl5/lib/FindBin.pm
2000-06-25 11:04:01 +00:00

170 lines
4.2 KiB
Perl

# FindBin.pm
#
# 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.
=head1 NAME
FindBin - Locate directory of original perl script
=head1 SYNOPSIS
use FindBin;
use lib "$FindBin::Bin/../lib";
or
use FindBin qw($Bin);
use lib "$Bin/../lib";
=head1 DESCRIPTION
Locates the full path to the script bin directory to allow the use
of paths relative to the bin directory.
This allows a user to setup a directory tree for some software with
directories E<lt>rootE<gt>/bin and E<lt>rootE<gt>/lib and then the above example will allow
the use of modules in the lib directory without knowing where the software
tree is installed.
If perl is invoked using the B<-e> option or the perl script is read from
C<STDIN> then FindBin sets both C<$Bin> and C<$RealBin> to the current
directory.
=head1 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 - $Script with all links resolved
=head1 KNOWN BUGS
if perl is invoked as
perl filename
and I<filename> does not have executable rights and a program called I<filename>
exists in the users C<$ENV{PATH}> which satisfies both B<-x> and B<-T> then FindBin
assumes that it was invoked via the C<$ENV{PATH}>.
Workaround is to invoke perl as
perl ./filename
=head1 AUTHORS
FindBin is supported as part of the core perl distribution. Please send bug
reports to E<lt>F<perlbug@perl.org>E<gt> using the perlbug program included with perl.
Graham Barr E<lt>F<gbarr@pobox.com>E<gt>
Nick Ing-Simmons E<lt>F<nik@tiuk.ti.com>E<gt>
=head1 COPYRIGHT
Copyright (c) 1995 Graham Barr & Nick Ing-Simmons. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=cut
package FindBin;
use Carp;
require 5.000;
require Exporter;
use Cwd qw(getcwd abs_path);
use Config;
use File::Basename;
use File::Spec;
@EXPORT_OK = qw($Bin $Script $RealBin $RealScript $Dir $RealDir);
%EXPORT_TAGS = (ALL => [qw($Bin $Script $RealBin $RealScript $Dir $RealDir)]);
@ISA = qw(Exporter);
$VERSION = "1.42";
BEGIN
{
*Dir = \$Bin;
*RealDir = \$RealBin;
if($0 eq '-e' || $0 eq '-')
{
# perl invoked with -e or script is on C<STDIN>
$Script = $RealScript = $0;
$Bin = $RealBin = getcwd();
}
else
{
my $script = $0;
if ($^O eq 'VMS')
{
($Bin,$Script) = VMS::Filespec::rmsexpand($0) =~ /(.*\])(.*)/s;
($RealBin,$RealScript) = ($Bin,$Script);
}
else
{
my $IsWin32 = $^O eq 'MSWin32';
unless(($script =~ m#/# || ($IsWin32 && $script =~ m#\\#))
&& -f $script)
{
my $dir;
foreach $dir (File::Spec->path)
{
my $scr = File::Spec->catfile($dir, $script);
if(-r $scr && (!$IsWin32 || -x _))
{
$script = $scr;
if (-f $0)
{
# $script has been found via PATH but perl could have
# been invoked as 'perl file'. Do a dumb check to see
# if $script is a perl program, if not then $script = $0
#
# well we actually only check that it is an ASCII file
# we know its executable so it is probably a script
# of some sort.
$script = $0 unless(-T $script);
}
last;
}
}
}
croak("Cannot find current script '$0'") unless(-f $script);
# Ensure $script contains the complete path incase we C<chdir>
$script = File::Spec->catfile(getcwd(), $script)
unless File::Spec->file_name_is_absolute($script);
($Script,$Bin) = fileparse($script);
# Resolve $script if it is a link
while(1)
{
my $linktext = readlink($script);
($RealScript,$RealBin) = fileparse($script);
last unless defined $linktext;
$script = (File::Spec->file_name_is_absolute($linktext))
? $linktext
: File::Spec->catfile($RealBin, $linktext);
}
# Get absolute paths to directories
$Bin = abs_path($Bin) if($Bin);
$RealBin = abs_path($RealBin) if($RealBin);
}
}
}
1; # Keep require happy