Since your dates are already in a format that is easily sorted, just use a simple '>' comparison to the one week ago date value.

use DateTime;

use strict;
use warnings;

my $oneweekago = DateTime->now()->subtract(days => 7)->strftime("%Y%m%
+d");

while (<DATA>) {
    print if /(\d{8})/ && $1 > $oneweekago;
}

=prints
abcd3.20110509-2345
=cut

__DATA__
abcd1.20110429-2345
abcd2.20110502-2345
abcd3.20110505-2345
abcd3.20110509-2345

[download]

Update: Changed implementation from POSIX to DateTime per ikegami

In reply to Re: date as part of filename by wind
in thread date as part of filename by zac_carl

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