Regular expression in Perl

Shell Programming and Scripting
1

Hi,

I need and expression for a word like abc_xyz_ykklm
The expresion should indicate that the word starts with abc and end with ykklm but does not contain xyz string in the middle.
Example: abc_tmn_ykklm is ok and abc_xyz_ykklm is not Ok.

Please help.

Regards.

2 
% ./s
enter string: abc_tmn_ykklm
abc_tmn_ykklm is ok
enter string: abc_xyz_ykklm
abc_xyz_ykklm is  not ok

% cat s
#!/usr/bin/perl

use warnings;
use strict;

my $p = qr/^abc_(?!xyz)[^_]*_ykklm$/;

while (1) {
  print "enter string: ";
  my $s = <>;
  chomp $s;
  print "$s is ", $s =~ /$p/o ? "" : " not " , "ok\n"; 
  }