Question

Frankly I don’t know Perl at all. I have to solve a problem using perl for some reasons. I tried searching for quick solutions and couldn’t find any (my bad)

Problem: I have got a file that has list of file names and a timestamps (i.e. 2012-05-24T18:19:35.000Z) in it.
I need to parse identify which of these are more that 90 days old.

I just need the check, everything else I think I have got in place already. When I googled some people suggested using some fancy datetime packages while some suggestions were around using of -M.

Quite confused actually. All help appreciated. Thanks.

Answer 1

That date format has the advantage that doing a lexicographical comparison between two of those string is (just about) the same as doing a date-time comparison. So you just need to get the date 90 days in the past into that format, and doing a string comparison.

use POSIX 'strftime';
$_90_days_ago = strftime("%FT%T.000Z", gmtime( time-90*86400 ));

...
foreach $date (@your_list_of_dates) {
    if ($date lt $_90_days_ago) {
        print "$date was at least 90 days ago.\n";
    } else {
        print "$date is less than 90 days ago.\n";
    }
}