1;# pwd.pl - keeps track of current working directory in PWD environment var
2;#
3#
4# This library is no longer being maintained, and is included for backward
5# compatibility with Perl 4 programs which may require it.
6#
7# In particular, this should not be used as an example of modern Perl
8# programming techniques.
9#
10# Suggested alternative: Cwd
11#
12;# $RCSfile: pwd.pl,v $$Revision: 4.1 $$Date: 92/08/07 18:24:11 $
13;#
14;# $Log:	pwd.pl,v $
15;#
16;# Usage:
17;#	require "pwd.pl";
18;#	&initpwd;
19;#	...
20;#	&chdir($newdir);
21
22package pwd;
23
24sub main'initpwd {
25    if ($ENV{'PWD'}) {
26	local($dd,$di) = stat('.');
27	local($pd,$pi) = stat($ENV{'PWD'});
28	if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) {
29	    chop($ENV{'PWD'} = `pwd`);
30	}
31    }
32    else {
33	chop($ENV{'PWD'} = `pwd`);
34    }
35    if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|) {
36	local($pd,$pi) = stat($2);
37	local($dd,$di) = stat($1);
38	if (defined $pd and defined $dd and $di == $pi and $dd == $pd) {
39	    $ENV{'PWD'}="$2$3";
40	}
41    }
42}
43
44sub main'chdir {
45    local($newdir) = shift;
46    $newdir =~ s|/{2,}|/|g;
47    if (chdir $newdir) {
48	if ($newdir =~ m#^/#) {
49	    $ENV{'PWD'} = $newdir;
50	}
51	else {
52	    local(@curdir) = split(m#/#,$ENV{'PWD'});
53	    @curdir = '' unless @curdir;
54	    foreach $component (split(m#/#, $newdir)) {
55		next if $component eq '.';
56		pop(@curdir),next if $component eq '..';
57		push(@curdir,$component);
58	    }
59	    $ENV{'PWD'} = join('/',@curdir) || '/';
60	}
61    }
62    else {
63	0;
64    }
65}
66
671;
68