G'day Dr Manhattan,

You say "... ending with ,|?|! ..." but your regex (s/(\.|\?|\!)$//) isn't removing commas. Is that the bit that isn't working? You really need to show your input and output: "it does not work" is an entirely inadequate error report.

I think you'd be better off with a single character class ([?!,]) than an alternation with all those escaped characters:

$ perl -Mstrict -Mwarnings -E '
    my @words = ("what?", "what!", "what,");
    say for map { s/[?!,]$//; $_ } @words;
'
what
what
what
[download]