What does "increment $| or set it to 1" mean for my CGI app?

isync has asked for the wisdom of the Perl Monks concerning the following question:

I am using CGI::Application::Plugin::Stream in one of the runmodes of a cgi app. And it sometimes behaves strange, especially under FCGI.

Now I came across this note in the ::Stream docs: "It's recommended that you increment $| (or set it to 1), which will autoflush the buffer as your application is streaming out the file."
The special vars docs say "$| means If set to nonzero, forces a flush after every write or print", but how do I use this in my cgi app?

Why doesn't ::Stream set it after it has finished printing stuff to STDOUT automagically?

Shall I do

$| = 1;
$self->stream_file( $file )
$| = 0;
return;
[download]

in my runmode?

Or does it mean I should switch the buffer mode in general for the whole app by stating $| = 1; in the setup() stage of CGI::App??

Comment on What does "increment $\| or set it to 1" mean for my CGI app? Download Code

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Re: What does "increment $\| or set it to 1" mean for my CGI app? by Anonymous Monk on Feb 04, 2012 at 14:28 UTC
Why doesn't ::Stream set it after it has finished printing stuff to STDOUT automagically? Its none of its business ?:) I really don't know, this Bug #37038 for CGI-Application-Plugin-Stream: PATCH: improved auto-buffering and error handling. indicated it should have been done in 2008, go figure Shall I do ... in my runmode? You may :) You may also write that as `{ local $\|=1; ... return; }` [download] Or does it mean I should switch the buffer mode in general for the whole app by stating $\| = 1; in the setup() stage of CGI::App?? It may. You could even `{ local $\|=1; my $app = MyCGIAppSubclass->new; $app->run; }` [download]	[reply] [d/l] [select]
Re: What does "increment $\| or set it to 1" mean for my CGI app? by Xiong (Hermit) on Feb 05, 2012 at 04:20 UTC
`my $prev_fh = select $outfh; local $\| = 1; # autoflush select $prev_fh;` [download] I'm not the guy you kill, I'm the guy you buy. —Michael Clayton	[reply] [d/l]

Replies are listed 'Best First'.
Re: What does "increment $\| or set it to 1" mean for my CGI app? by Anonymous Monk on Feb 04, 2012 at 14:28 UTC
Why doesn't ::Stream set it after it has finished printing stuff to STDOUT automagically? Its none of its business ?:) I really don't know, this Bug #37038 for CGI-Application-Plugin-Stream: PATCH: improved auto-buffering and error handling. indicated it should have been done in 2008, go figure Shall I do ... in my runmode? You may :) You may also write that as `{ local $\|=1; ... return; }` [download] Or does it mean I should switch the buffer mode in general for the whole app by stating $\| = 1; in the setup() stage of CGI::App?? It may. You could even `{ local $\|=1; my $app = MyCGIAppSubclass->new; $app->run; }` [download]	[reply] [d/l] [select]
Re: What does "increment $\| or set it to 1" mean for my CGI app? by Xiong (Hermit) on Feb 05, 2012 at 04:20 UTC
`my $prev_fh = select $outfh; local $\| = 1; # autoflush select $prev_fh;` [download] I'm not the guy you kill, I'm the guy you buy. —Michael Clayton	[reply] [d/l]