Hello Monks, I have a small, yet significant issue. I have a rather large script that generates configuration files for network elements. The problem is that these elements have character limitations on several of the parameters, and currently I am manually manipulating output files to ensure we stay within the character limit. Obviously this makes for easy work errors. One of my input files looks like this: 
NT8
NT9
NT10
NT11

[download]
What I need perl to do is check each line in the file, and if it is three characters, add a '_' at the end, but omit that underscore if it is 4 characters, so it would look like this: 
NT8_
NT9_
NT10
NT11

[download]
As usual, any and all help is appreciated.

In reply to How to have perl check line length by ddrew78

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