Update: Since the original code was severely buggy, I substituted it altogether with that also posted in this followup. The original code is available here.

This is another short program that for me is a complete application, and I hope that this time there's not a common utility to do the same...

Basically it expands strings of the form

foo[01:100]bar-[fred,barney,wilma]
[download]

to the list

foo01bar-fred
foo02bar-fred
...
foo100bar-fred
foo01bar-barney
...
foo100bar-wilma
[download]

More info here!

#!/usr/bin/perl -ln

use strict;
use warnings;

sub expand;
sub doit;

print for expand $_;

sub expand {
    doit split /\[(.*?)\]/, shift, -1;
}

sub doit {
    return @_ if @_ == 1;
    my ($pre,$pat,$post)=splice @_, 0, 3;
    map { doit $pre . $_ . $post, @_ }
      map { /(\w+):(\w+)/ ? $1..$2 : $_ }
      split /,/, $pat;
    }

__END__
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