Perl operator: $|++; dollar sign pipe plus plus

Question

I\'m working on a new version of an already released code of perl, and found the line:

$|++;

AFAIK, $| is related with pipes, as explained

Answer 1

It's an old idiom, from the days before IO::Handle. In modern code this should be written as

use IO::Handle; STDOUT->autoflush(1);