#!/usr/bin/perl
$/="\nFrom ";
use Email::Simple;
use Getopt::Std;
my %opts;
getopt("sftT", \%opts);
my $term=shift @ARGV;
MAIN: while (<>) {
    chomp;
    # Quick scan, to weed out common non-matches.
    next if $opts{s} and !/Subject:.*$opts{s}.*$/m;
    next if $opts{f} and !/From:.*$opts{f}/m;
    next if $opts{T} and !/(To|Cc):.*$opts{T}/m;
    next if $opts{t} and !/To:.*$opts{t}/m;
    next if $term and not m/$term/;
    # Detailed scan.
    $_="From $_\n";
    my $item = new Email::Simple ($_);
    next if $opts{s} and $item->header(q/Subject/) !~ /$opts{s}/;
    next if $opts{f} and $item->header(q/From/)    !~ /$opts{f}/;
    next if $opts{t} and $item->header(q/To/)      !~ /$opts{t}/;
    next if $opts{T} and $item->header(q/To/)      !~ /$opts{T}/ and 
                         $item->header(q/Cc/)      !~ /$opts{T}/;
    next if $term    and $item->body       !~ /$term/smi;
    print;
}