;# pwd.pl - keeps track of current working directory in PWD environment var
;#
#
# This library is no longer being maintained, and is included for backward
# compatibility with Perl 4 programs which may require it.
#
# In particular, this should not be used as an example of modern Perl
# programming techniques.
#
# Suggested alternative: Cwd
#
;# $RCSfile: pwd.pl,v $$Revision: 4.1 $$Date: 92/08/07 18:24:11 $
;#
;# $Log: pwd.pl,v $
;#
;# Usage:
;# require "pwd.pl";
;# &initpwd;
;# ...
;# &chdir($newdir);

package pwd;

sub main'initpwd {
if ($ENV{'PWD'}) {
local($dd,$di) = stat('.');
local($pd,$pi) = stat($ENV{'PWD'});
if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) {
chop($ENV{'PWD'} = `pwd`);
}
}
else {
chop($ENV{'PWD'} = `pwd`);
}
if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|) {
local($pd,$pi) = stat($2);
local($dd,$di) = stat($1);
if (defined $pd and defined $dd and $di == $pi and $dd == $pd) {
$ENV{'PWD'}="$2$3";
}
}
}

sub main'chdir {
local($newdir) = shift;
$newdir =~ s|/{2,}|/|g;
if (chdir $newdir) {
if ($newdir =~ m#^/#) {
$ENV{'PWD'} = $newdir;
}
else {
local(@curdir) = split(m#/#,$ENV{'PWD'});
@curdir = '' unless @curdir;
foreach $component (split(m#/#, $newdir)) {
next if $component eq '.';
pop(@curdir),next if $component eq '..';
push(@curdir,$component);
}
$ENV{'PWD'} = join('/',@curdir) || '/';
}
}
else {
0;
}
}

1;