The code works fine for me : Output: 
$ perl pm1.pl < pm1-dat.txt
george:2~~14
nick:5~~10~~20
peter:3

[download]
My perl : This is perl 5, version 34, subversion 0 (v5.34.0) built for x86_64-linux-gnu-thread-multi

Your code uses an un-declared $a which is also used by sort.
Your perl seems to encounter side-effects of that.
I recommend you use a declared variable NOT named $a, or $b.

                "These opinions are my own, though for a small fee they be yours too."

In reply to Re: Why is my code producing weird output? by NetWallah
in thread Why is my code producing weird output? by Anonymous Monk

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