use strict;
local $| = 1; #Autoflush true
my $file = 'c:/cygwin/var/log/setup.log';
die "tail nicht installiert\n" unless qx/which tail/;
open(TAIL,"tail -f $file |") or die $!;
while(my $line = <TAIL>){
 print "$.: $line\n";
 print "Gefunden\n" if $line =~ m/DEIN_PATTERN/;
}
close TAIL; # schließe die Pipe