$text = "0000 636d6400 5589e583 ec0831c0 83e4f0e8 cmd.U.....1.....
0010 00000000 e8000000 0083ec0c 68000000 ............h...
0020 00e80000 000031c0 c9c39090 90909090 ......1.........";
$text =~ s/[0-9a-f]{4}//g