$ perldoc perlhist ... Perl 1 introduced Perl to the world, and changed /\(...\|...\)/ to /(...|...)/. \(Dan Faigin still hasn't forgiven me. :−\) となっていて、Perl version 0の頃はsed形式だったんだなと。変えた理由は想像がつくけど、一応調…