in reply to Little annoying mistakes ... of others
To extend what ikegami said above-
substitute returns true/false and not the changed string even in map
Substitute does not return true/false. It returns the count of substitutions performed.
perl -le '$str = "A.B.C."; $x = $str =~ s/\w//g; print $x' 3 # or a "1" without the "g."
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