Re: not waiting for external command to complete before getting the output

Try

open PROG,"program|" or die "Cannot fork";
while (<PROG>) {

 # do stuff...
}
[download]

This also depends on your called program not buffering its output.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

Comment on Re: not waiting for external command to complete before getting the output Download Code

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Re: Re: not waiting for external command to complete before getting the output by hambo (Novice) on Apr 26, 2004 at 18:31 UTC
cdrecord seems to be buffering output Thanks guys. Been away making supper. Now, Seems like this silly cdrecord thing is buffering the output. I tried what was suggested and noting was output until the enture cd had completed the record (which of course by that stage is way too late). So, now the question is: how do I get hold of this output without hacking cdrecord? `perl -e 'open (FD1, "/usr/bin/cdrecord -vs -dummy -eject /mnt/test/Deb +ian/2disc.iso \|"); while (<FD1>) { $_ =~ s/^M//g; print $_ if /^Track/; }; close (FD1)` [download] My output looks like: Track 01: 0 of 47 MB written.Track 01: 1 of 47 MB written (fifo 96%).....etc. Thanks for the help so far. Cheers H	[reply] [d/l]
Re: Re: Re: not waiting for external command to complete before getting the output by Joost (Canon) on Apr 26, 2004 at 19:03 UTC
It is likely outputting something without newlines (i.e. "\r" instead of "\n"), so you could try setting your input record seperator to that, for instance: `local $/ = "\r";` Also see the perlfunc section on `getc` for more info on input buffering. Hope this helps, Joost. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l] [select]