#!/usr/bin/perl
#
# AIX wtmp Cleaner
#
###################
use strict;
use warnings;

my $tmpfile = '/tmp/wtmp.ascii';
my $regex = qr/((?:\w{3}\s+){2}\d+\s+(?:\d+:){2}\d\d\s+[A-Z]{3}\s+\d{4})$/;
my $date = `date`;
my @cdate = split(/ /, $date);
my $cmonth = mapmonth($cdate[1]);

sub bin2ascii {
        system("/usr/lib/acct/fwtmp < ./wtmp_testfile > /tmp/wtmp.ascii");
}
sub ascii2bin {
        system("/usr/lib/acct/fwtmp -ci < /tmp/wtmp.ascii > ./wtmp_testfile");
}
sub mapmonth {
        my %mnr=('Jan', 1, 'Feb', 2, 'Mar', 3, 'Apr', 4, 'Mai', 5, 'Jun', 6, 'Jul', 7, 'Aug', 8, 'Sep', 9, 'Oct', 10, 'Nov', 11, 'Dec', 12);
        my $monat=$mnr{$_[0]};
        return($monat);
}

sub ripdates {
        my $date = `date`;
        my @date_now = split(/ /,$date);
        my $currentmonth = $date_now[1];
        my $mappedmonth = mapmonth($currentmonth);
        open my $fh, '<', $tmpfile or die $!;
        unlink "wtmpfile.new";
        while(my $line = <$fh>) {
                        foreach ($line) {
                                my @regexped = ($line =~ $regex);
                                my @datestring = split(/ /,$regexped[0]);
                                my $daynr = $datestring[0];
                                my $monthnr = mapmonth($datestring[1]);
                                if ($monthnr eq $cmonth) {
                                        open(NEWWTMP,">>wtmpfile.new");
                                        print NEWWTMP $_;
                                        print ("Month: $cmonth -> $line\n");
                                }
                        }
        }
        close $fh;
        close (NEWWTMP);
}

print("Loesche wtmp Eintraege der letzten 4 Wochen...\n");
bin2ascii();
ripdates();
#ascii2bin();
#unlink $tmpfile;
#unlink wtmpfile.new;