output external program results at runtime

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

dear monks, I have written a couple of scripts to launch largeish programs that i use at work,
some web stuff, some system stuff and some virtual environment stuff... the way i normally do it is something like...

my $launchDir = "/usr/launchDir";
my @progRes = `programOfInterest`;
my $num =0;
my $i;


foreach $i (@progRes)
{
  print "LINE : ".$num." Val ".$i;
  $num++;
}

# leaves the terminal open
my $pause = <STDIN>;
[download]

which prints the result line by line but AFTER execution...
as some of these programs i am running are large and sometimes fail.. it would be really great if i could somehow view the results at execution time.
as the above method executes and then returns the reults in the variable ?
any help would be appreciated

Comment on output external program results at runtime Download Code

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Re: output external program results at runtime by ikegami (Patriarch) on Feb 08, 2011 at 21:59 UTC
`open(my $FROM_CHLD, '-\|', 'programOfInterest') or die; while (<$FROM_CHLD>) { print("LINE: $. Val $_"); }` [download] The child may decide to buffer its output. The child may be convinced not to buffer its output if you use a pseudo tty.	[reply] [d/l]