How do you get the first existing ancestor directory given a file path?

Question

In Perl, if given a file path, how do you find the first existing ancestor?

For example:

• If given the path /opt/var/DOES/NOT/EXIST/wtv/blarg.txt and directory /opt/var/DOES/ is not present but directory /opt/var/ is, the result should be /opt/var/.
• If given the path /home/leguri/images/nsfw/lena-full.jpg and directory /home/leguri/images/nsfw/ does not exist, but directory /home/leguri/images/ does, the result should be /home/leguri/images/.

Is there a module or function which does this, or is it just a matter of splitting the path on / and testing for existence?

Answer 1

The closest I know of is Path::Class, which doesn't do exactly what you want but may save you a couple of steps in splitting the path.

use Path::Class 'dir';

sub get_existing_dir {
    my ( $path ) = @_;

    my $dir = dir( $path );
    while (!-d $dir) {
        $dir = $dir->parent;
    }
    return $dir->stringify;
}

my $file = '/opt/var/DOES/NOT/EXIST/wtv/blarg.txt';
my $dir = get_existing_dir( $file );
print $dir;