MH format mail file simple parser.

mhls

#!/usr/bin/perl
# mhls MH_FILENAME ...
# MH 形式のファイルを引数に与えるとファイルサイズとDateヘッダから導き出される日付を表示します

use strict;
use warnings;

use Date::Format qw(time2str);
use Date::Parse qw(str2time);
use List::Util qw(first);
use Term::ANSIColor qw(colored);

my @mh_filenames;

for my $filename (@ARGV) {
    my $filename = shift;
    if ( !-f $filename ) {
        warn colored(qq(file "$filename" is not found.\n), "yellow");
    } else {
        push @mh_filenames, $filename;
    }
}

for my $filename (@mh_filenames) {
    my $mh = lookup_mh($filename);
    printf "%s\t%d\t%s\n", $filename, $mh->{size}, $mh->{format_date};
}

sub lookup_mh {
    my $filename = shift;
    open my $fh, '<', $filename;
    my @header;
    while (<$fh>) {
        chomp;
        last if /^$/;
        push @header, $_;
    }
    close $fh;
    my $date = search_date(\@header);
    my $size = -s $filename;
    my $format_date = time2str("%Y/%m/%d %H:%M:%S", str2time($date));
    return +{ date => $date, size => $size, format_date => $format_date };
}

sub search_date {
    my $array = shift;
    my $date = first { /^Date:/ } @$array;
    $date =~ s/^Date:\s*//i;
    return $date;
}