From: Perl 5 Porters <perl5-porters@africa.nicoh.com>
Date: Fri, 21 Jun 1996 02:27:09 +0000 (+0000)
Subject: Add FindBin library module
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=a73990fdb7aa812be91abe65dea1c0c2af4eb8ed;p=p5sagit%2Fp5-mst-13.2.git

Add FindBin library module
---

diff --git a/lib/FindBin.pm b/lib/FindBin.pm
new file mode 100644
index 0000000..ecfa300
--- /dev/null
+++ b/lib/FindBin.pm
@@ -0,0 +1,232 @@
+# 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;
+ BEGIN { unshift(@INC,"$FindBin::Bin/../lib") }
+
+ or 
+
+ use FindBin qw($Bin);
+ BEGIN { unshift(@INC,"$Bin/../lib") }
+
+=head1 DESCRIPTION
+
+Locates the full path to the script bin directory to allow the use
+of paths relative to the bin directory.
+
+This allows a user to setup a directory tree for some software with
+directories <root>/bin and <root>/lib and then the above example will allow
+the use of modules in the lib directory without knowing where the software
+tree is installed.
+
+If perl is invoked using the -e option or the perl script is read from
+C<STDIN> then FindBin sets both C<$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 -x and -T then FindBin
+assumes that it was invoked via the C<$ENV{PATH}>.
+
+Workaround is to invoke perl as
+
+ perl ./filename
+
+=head1 AUTHORS
+
+Graham Barr <bodg@tiuk.ti.com>
+Nick Ing-Simmons <nik@tiuk.ti.com>
+
+=head1 COPYRIGHT
+
+Copyright (c) 1995 Graham Barr & Nick Ing-Simmons. All rights reserved.
+This program is free software; you can redistribute it and/or modify it
+under the same terms as Perl itself.
+
+=head1 REVISION
+
+$Revision: 1.4 $
+
+=cut
+
+package FindBin;
+use Carp;
+require 5.000;
+require Exporter;
+use Cwd qw(getcwd);
+
+@EXPORT_OK = qw($Bin $Script $RealBin $RealScript $Dir $RealDir);
+%EXPORT_TAGS = (ALL => [qw($Bin $Script $RealBin $RealScript $Dir $RealDir)]);
+@ISA = qw(Exporter);
+
+$VERSION = $VERSION = sprintf("%d.%02d", q$Revision: 1.4 $ =~ /(\d+)\.(\d+)/);
+
+# Taken from Cwd.pm It is really getcwd with an optional
+# parameter instead of '.'
+#
+# another way would be:
+#
+#sub abs_path
+#{
+# my $cwd = getcwd();
+# chdir(shift || '.');
+# my $realpath = getcwd();
+# chdir($cwd);
+# $realpath;
+#}
+
+sub abs_path
+{
+    my $start = shift || '.';
+    my($dotdots, $cwd, @pst, @cst, $dir, @tst);
+
+    unless (@cst = stat( $start ))
+    {
+	warn "stat($start): $!";
+	return '';
+    }
+    $cwd = '';
+    $dotdots = $start;
+    do
+    {
+	$dotdots .= '/..';
+	@pst = @cst;
+	unless (opendir(PARENT, $dotdots))
+	{
+	    warn "opendir($dotdots): $!";
+	    return '';
+	}
+	unless (@cst = stat($dotdots))
+	{
+	    warn "stat($dotdots): $!";
+	    closedir(PARENT);
+	    return '';
+	}
+	if ($pst[0] == $cst[0] && $pst[1] == $cst[1])
+	{
+	    $dir = '';
+	}
+	else
+	{
+	    do
+	    {
+		unless (defined ($dir = readdir(PARENT)))
+	        {
+		    warn "readdir($dotdots): $!";
+		    closedir(PARENT);
+		    return '';
+		}
+		$tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir"))
+	    }
+	    while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] ||
+		   $tst[1] != $pst[1]);
+	}
+	$cwd = "$dir/$cwd";
+	closedir(PARENT);
+    } while ($dir);
+    chop($cwd); # drop the trailing /
+    $cwd;
+}
+
+
+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) =~ /(.*\])(.*)/;
+     ($RealBin,$RealScript) = ($Bin,$Script);
+    }
+   else
+    {
+     unless($script =~ m#/# && -f $script)
+      {
+       my $dir;
+       
+       foreach $dir (split(/:/,$ENV{PATH}))
+	{
+	if(-x "$dir/$script")
+         {
+          $script = "$dir/$script";
+   
+	  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 = getcwd() . "/" . $script unless($script =~ m,^/,);
+   
+     ($Bin,$Script) = $script =~ m,^(.*?)/+([^/]+)$,;
+  
+     # Resolve $script if it is a link
+     while(1)
+      {
+       my $linktext = readlink($script);
+  
+       ($RealBin,$RealScript) = $script =~ m,^(.*?)/+([^/]+)$,;
+       last unless defined $linktext;
+  
+       $script = ($linktext =~ m,^/,)
+                  ? $linktext
+                  : $RealBin . "/" . $linktext;
+      }
+
+     # Get absolute paths to directories
+     $Bin     = abs_path($Bin)     if($Bin);
+     $RealBin = abs_path($RealBin) if($RealBin);
+    }
+  }
+}
+
+1; # Keep require happy
+