distrib/lib/fastcwd.pl

# By John Bazik
#
# 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 = &fastcwd;
#
# This is a faster version of getcwd.  It's also more dangerous because
# you might chdir out of a directory that you can't chdir back into.

sub fastcwd {
    local($odev, $oino, $cdev, $cino, $tdev, $tino);
    local(@path, $path);
    local(*DIR);

    ($cdev, $cino) = stat('.');
    for (;;) {
        ($odev, $oino) = ($cdev, $cino);
        chdir('..');
        ($cdev, $cino) = stat('.');
        last if $odev == $cdev && $oino == $cino;
        opendir(DIR, '.');
        for (;;) {
            $_ = readdir(DIR);
            next if $_ eq '.';
            next if $_ eq '..';

            last unless $_;
            ($tdev, $tino) = lstat($_);
            last unless $tdev != $odev || $tino != $oino;
        }
        closedir(DIR);
        unshift(@path, $_);
    }
    chdir($path = '/' . join('/', @path));
    $path;
}
1;