Hi, the problem with your regex:

 if ( $this_server =~ m/^(\w+)_/ ) { 
     $this_server = $1; 
}
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is greedy matching: the expression tries to capture as much as possible until the last "_". Try to change it to a non greedy quantifier (+? instead of +:

 if ( $this_server =~ m/^(\w+?)_/ ) { 
     $this_server = $1; 
}
[download]

Update: Oops, I had not noticed that you actually had found the same solution by yourself (your second post), in part due to the fact that is is poorly formated. BTW, for a closing format tag, you should use a forward slash, not a back slash.