That sounds like one of those super useful features that's easy to shoot yourself in the foot with. Perl has a few of those (cribbed from AWK, I believe): $, :

That sounds like one of those super useful features that's easy to shoot yourself in the foot with. Perl has a few of those (cribbed from AWK, I believe): $, : The output field separator $ perl -E 'my @data = (11,22,33); say 11,22,33; say "@data"; say @data; $,="|"; say 11,22,33; say "@data"; say @data;' 112233 11 22 33 112233 11|22|33 11 22 33 11|22|33 $" : Interpolated list separator $ perl -E 'my @data = (11,22,33); say 11,22,33; say "@data"; say @data; $"="|"; say 11,22,33; say "@data"; say @data;' 112233 11 22 33 112233 112233 11|22|33 112233 And a bunch more, including input line/record separators (so you can slurp a whole file into a buffer at once instead of line by line), etc.