#!/usr/bin/perl -00 # datesort - sort mbox by subject then date use strict; use Date::Manip; my @msgs = (); while (<>) { next unless /^From/m; my $date = ''; if (/^Date:\s*(.*)/m) { ($date = $1) =~ s/\s+\(.*//; # library hates (MST) $date = ParseDate($date); } push @msgs, { SUBJECT => /^Subject:\s*(?:Re:\s*)*(.*)/mi, DATE => $date, NUMBER => scalar @msgs, TEXT => '', }; } continue { $msgs[-1]{TEXT} .= $_; } for my $msg (sort { $a->{SUBJECT} cmp $b->{SUBJECT} || $a->{DATE} cmp $b->{DATE} || $a->{NUMBER} <=> $b->{NUMBER} } @msgs ) { print $msg->{TEXT}; }