#!/usr/bin/perl -w

my $FROM     = 'absender@irgendwo.com';
my @TO       = qw(logs@perlmeister.com);
my $SUBJECT  = 'Today\'s Logs';
my $MAXLINES = 10;
my $DATABASE = '/home/mschilli/tmp/logmail.dat';
my $B        = '/home/mschilli/tmp';

my @FILES = ("Neukunden"  => "$B/rbsub.txt",
             "Fehler"     => "$B/errors.txt",
            );
use strict;
use Mail::Mailer;
use Storable;

my $offs = {};

if(-r $DATABASE) {
        # Gespeicherte Daten auslesen
    $offs = retrieve($DATABASE) or 
        die "Cannot open $DATABASE";   
}

my $mailtext = "";

while(my ($text, $file) = splice(@FILES, 0, 2)) {

        # Teilüberschrift
    $mailtext .= "\n" . "#" x 70;
    $mailtext .= "\n$text:\n";
    $mailtext .= "#" x 70 . "\n";

        # Gespeicherter Offset vom letzten Mal
    my $offset = ($offs->{$file} || 0);

    if(open(FILE, "<$file")) {
        if(-s $file < $offset) {
                # Datei wurde gekürzt
            $offs->{$file} = -s $file;
            $mailtext .= "(Offset adjusted)\n";
        } else {
                # Bis zum gespeicherten Offset
                # vorfahren
            seek(FILE, $offset, 0);

                # Rest zeilenweise auslesen
            my @data = <FILE>;
            my $noflines = @data;

                # Neuen Offset einstellen
            $offs->{$file} = tell(FILE);

                # Kürzen falls > $MAXLINES
            if(@data > $MAXLINES) {
                splice(@data, $MAXLINES/2, 
                       @data-$MAXLINES, "...\n");
            }
            my $data = join '', @data;

                # Zeilenzahl ausgeben
            $mailtext .= sprintf "(%d line%s)\n", 
                       $noflines,
                       $noflines == 1 ? "" : "s";
                # Logdaten ausgeben
            $mailtext .= $data;
            close(FILE);
        }
    } else {
        $mailtext .= "Cannot open $file\n";
    }
}

mailto($SUBJECT, $mailtext, $FROM, @TO);

store($offs, $DATABASE) or 
    die "Cannot store data in $DATABASE";

##################################################
sub mailto {
##################################################
    my ($subj, $text, $from, @to) = @_;

    return if @to == 0;

    my $mailer = Mail::Mailer->new( 'sendmail' );
    my $to = join ", ", @to;

    $mailer->open( { "To"       => $to,
                     "From"     => $from,
                     "Subject"  => $subj,
                     "Reply-To" => $from,
                   } ) or die "open failed";

    print $mailer $text;
    $mailer->close();
}