Re: Re: Re: POE, was Re: Tk tail -f


"be consistent"
	PerlMonks

Re: Re: Re: POE, was Re: Tk tail -f - How?

by msemtd (Scribe)

on Oct 09, 2003 at 13:38 UTC ( [id://297910]=note: print w/replies, xml )

Need Help??

in reply to Re: Re: POE, was Re: Tk tail -f - How?
in thread Tk tail -f - How?

Of course :) after insert task I have added...

my $trim = $listbox->size - $maxlines;
$listbox->delete(0, $trim-1) if trim > 0;
[download]

I accept the point re last-read-to-seek-delay-data-loss: any ideas anyone?

Otherwise I don't see any harm with the seek(F,0,1) - isn't it required in order to clear the EOF condition as per docs?

Comment on Re: Re: Re: POE, was Re: Tk tail -f - How? Download Code

Replies are listed 'Best First'.

Re: Re: Re: Re: POE, was Re: Tk tail -f - How?
by BrowserUk (Patriarch) on Oct 09, 2003 at 18:01 UTC

any ideas anyone?

What my one-liner above demonstrated was that if you read the file with the diamond operator, the way you detect eof, is when it returns undef. If you simply ignore the undefs and continue reading, the eof condition clears itself without any further action required..

Given the docs you cite, I'm not sure if this is "working as designed" or an an undocumented and therefore unreliable feature, but it has worked this way in every version of perl I've used. About the oldest script I have that I still use makes use of this feature.

Examine what is said, not who speaks.

"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail

[reply]

In Section Seekers of Perl Wisdom