source: trunk/essentials/dev-lang/perl/lib/getcwd.pl

# By Brandon S. Allbery
#
# 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
#
#
# Usage: $cwd = &getcwd;

sub getcwd
{
    local($dotdots, $cwd, @pst, @cst, $dir, @tst);

    unless (@cst = stat('.'))
    {
        warn "stat(.): $!";
        return '';
    }
    $cwd = '';
    do
    {
        $dotdots .= '/' if $dotdots;
        $dotdots .= '..';
        @pst = @cst;
        unless (opendir(getcwd'PARENT, $dotdots))                       #'))
        {
            warn "opendir($dotdots): $!";
            return '';
        }
        unless (@cst = stat($dotdots))
        {
            warn "stat($dotdots): $!";
            closedir(getcwd'PARENT);                                    #');
            return '';
        }
        if ($pst[$[] == $cst[$[] && $pst[$[ + 1] == $cst[$[ + 1])
        {
            $dir = '';
        }
        else
        {
            do
            {
                unless (defined ($dir = readdir(getcwd'PARENT)))        #'))
                {
                    warn "readdir($dotdots): $!";
                    closedir(getcwd'PARENT);                            #');
                    return '';
                }
                unless (@tst = lstat("$dotdots/$dir"))
                {
                    # warn "lstat($dotdots/$dir): $!";
                    # closedir(getcwd'PARENT);                          #');
                    # return '';
                }
            }
            while ($dir eq '.' || $dir eq '..' || $tst[$[] != $pst[$[] ||
                   $tst[$[ + 1] != $pst[$[ + 1]);
        }
        $cwd = "$dir/$cwd";
        closedir(getcwd'PARENT);                                        #');
    } while ($dir ne '');
    chop($cwd);
    $cwd;
}

1;