--
perl -pew "s/\b;([mnst])/'$1/g"

the whole ARGV/STDIN

Excuse me? There's no use of STDIN in that program. An empty diamond is the same as <ARGV>, not <STDIN>.

And beginning Perl hackers who confuse the two will eventually get burned. My rule is to never use <> (aka <ARGV>) if you ever print some kind of prompt, and I flunk any use to the contrary in code review. Work it out for yourself to see why. The proper use for interaction where you prompt and read input is <STDIN>.

-- Randal L. Schwartz, Perl hacker

Well yes, I new it was the ARGV filehandle, but I tend to think of waka waka as STDIN. If @ARGV is empty waka waka reads from STDIN.

(I'd even contemplated writing magic ARGV but decided against it ;-)

--
perl -pew "s/\b;([mnst])/'$1/g"

I just tried this on perl 5.005_02 and I found that it would not work with local *ARGV but local @ARGV worked.

I assume localizing the ARGV filehandle somehow broke the <ARGV> magic. It works correctly on perl 5.6.0.