Question

I’m still useless when it comes to creating regex patterns. This one has got to be really easy.

Given the string: /home/users/cheeseconqueso/perl.pl

I want to place the string ./ right in front of the very last / in the original string to produce: /home/users/cheeseconqueso/./perl.pl

Thanks in advance – I’m sure this simple example will help me for a lot of other stupid stuff that shouldn’t be up here!

Answer 1

Here’s my solution based on what I was thinking of when I left the comment to your question:

use strict;
use warnings;

my $str = '/home/users/cheeseconqueso/perl.pl';
my @arr = split('/',$str);
my $newstr = join('/', @arr[0..(@arr-2)], '.', $arr[-1]);

Edit: If you’re really keen on using a regex, this is the simplest one I’ve found:

$str =~ s|(.*/)(.*)|$1./$2|;

It takes advantage of the greediness of the initial * in the first group to take every character up to the last /, then matches everything else in the second group. It’s a little easier to read with the | delimiters so you avoid leaning toothpick syndrome.