Re: print output from system command in real time

You could try something like

open SYS, "command |" or die "$!";
while (<SYS>) {
  print
}
close SYS;
[download]

but a lot depends on whether 'command' buffers its output, among other variables. You should probably read perldoc perlipc for more insight.

Comment on Re: print output from system command in real time Download Code

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Re^2: print output from system command in real time by boat73 (Scribe) on May 10, 2005 at 18:53 UTC
Thanks but that did not work. I built a standalone exe from the following code. Oh and I am doing this on windowz to make it even more fun. `until($cnt == "100"){ print "COUNT IS $cnt\n"; sleep 5; $cnt++; }` [download] I then call the exe within perl. With the code you supplied it still waits until completion before printing. I even tried setting autoflush with the code below. `open SYS, "c:\\temp\\junk.exe \|" or die "$!"; $oldfh=select(SYS); $\| = 1; select($oldfh); $\| = 1; while (<SYS>) { print } close SYS;` [download]	[reply] [d/l] [select]
Re^3: print output from system command in real time by Joost (Canon) on May 10, 2005 at 18:57 UTC
Your standalone program is buffering its output. Try setting `$\|=1;` (update: in the printing program!) before printing anything. $\| has no effect on reading, only on output. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]
Re^4: print output from system command in real time by boat73 (Scribe) on May 11, 2005 at 12:08 UTC
Hmmm, the problem is that the exe I am truly running does the same thing and I am unable to modify that code. System didn't work, still waits til completion to print.	[reply]


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