Perl one liners

Join multiple lines:

perl -le 'print join " ", map { chomp; $_ } <>'

Convert unix timestamps:

perl -e 'print scalar localtime (TIMESTAMP)'

Time zone calculator

To work out local GMT time use something like:

use POSIX qw(strftime);
strftime "%a %b %e %H:%M:%S %Y", gmtime;

Then either deduct or add in seconds, to work out time in a different time zone. Something like this:

# or for GMT formatted appropriately for your locale:
my $london = strftime "%a %b %e %H:%M:%S %Y", gmtime;
print "London   $london\n";

# 8h * 60 min = 240 * 60 sec = 28800
my $seattle = strftime "%a %b %e %H:%M:%S %Y", gmtime(time - 28800);
print "Seattle   $seattle 8 hours behind\n";

Nothing crazy, but useful.