STDOUT->autoflush(1) 在 Perl 中做什么？

Question

I've found a variety of information regarding autoflushing in Perl, but can't find any mention of a line formatted exactly like this:

STDOUT->autoflush(1);

This is included in a program I'm analyzing, and I want to understand better what it does. There is also this at the beginning of the program:

use IO::Handle;

...which I think might be related, but it also doesn't mention this method in its documentation.

Answer 1

The method is listed in IO::Handle which you noticed

... $io->autoflush ( [BOOL] ) $| ...

whereby $| is set/unset, and it sends you to $| in perlvar for explanation

If set to nonzero, forces a flush right away and after every write or print on the currently selected output channel.

As of v5.14 you don't have to use IO::Handle for this as IO::File is require d when needed.

This method is special in that it turns autoflush on even without value supplied,

$io->autoflush;  # turned on ($| gets set)

while other related ones don't change the current value when called without argument.