in reply to Favourite One-liners?

Though it is not the infallible oracle I once thought it was, I still make frequent use of

% perl -MO=Deparse,-p -e '<Perl code>' figure out how perl is parsing something, or maybe to get a grip on some obfu. E.g. if you wonder what this one-liner does
-nle '}{print$.' foobar.txt
feed it to -MO=Deparse,-p (make sure to retain any other command line switches, like -nl here):
% perl -MO=Deparse,-p -nle '}{print$.' BEGIN { $/ = "\n"; $\ = "\n"; } LINE: while (defined(($_ = <ARGV>))) { chomp($_); } { print($.); } -e syntax OK
Note that the -p in this one-liner is part not perl's command line switch, but rather an argument to B::Deparse.

Less commonly , I use other backends, such as B::Terse and B::Concise, instead of B::Deparse. See also O and B.

the lowliest monk