I recently needed to compile an automatic image show with a digital projector which could show JPG images by itself. However, it showed them sorted by time, oldest image first, not by name (I did name them 000.jpg, 001.jpg, etc.). So I decided to change the modification dates in an incremental way. A simply shell loop with touch didn't give good enough results, I need to add sleep 1; (or even 2) which of course takes too long.

So, Perl came to the rescue: The following small script takes a list of files and gives the last file the current time while every previous file is dated one second earlier. This worked very well with my projector.

#!/usr/bin/perl
use strict;
use warnings;

my $timestamp = time;

for my $file (reverse @ARGV) {
    utime $timestamp, $timestamp, $file;
    $timestamp--;
}
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