STDOUT qustion

[Noame]

Hi,

I’ve perl program P1.pl which calling to P2.pl.
Once P2.pl is starting to run I’m printing a message from P1.pl but the output from P2.pl which printings to the screen disappears.
Just in the end of P2.pl all the STDOUT buffer is printing to the screen
Following is my code from P1.pl:

$Cmd = "$HOME/bin/P2.pl";
        die print "\n\n-E- Files: '$Cmd does not exist.\n" if (-e $Cmd
+);
        
    print "\n-I- Executing:\n\t$Cmd\n";
    $status = system ($Cmd);
    
    if ($status)
    {
        my $errMsg = "-E- Failed to execute:\n\t$Cmd ";
        print  "\n\n$errMsg\n";
        killBuild ("$errMsg");
        exit 1;    
    } else {
        print "\n-I- Script:\n\t'$Cmd\n   Completed successfully.\n";
    }

Please advice,
Thanks

[CountZero]

Perhaps you are Suffering from Buffering?

[linuxer]

What's that die print "..." statement? die already prints the string, no need for a dedicated print.

Your script dies, when P2.pl exists although the message says the contrary.

This code worked fine for me:

#!/usr/bin/perl
# 
# p2.pl
#
use strict;
use warnings;

# disable buffering of STDOUT; see the already mentioned "Suffering fr
+om Buffering"
$| = 1;

my $string = "Hello World!";

for ( split //, $string ) {
  print $_;
  sleep 1;
}

print "\n";

__END__

#! /usr/bin/perl
#
# p1.pl
#
use strict;
use warnings;

my $cmd = '/path/to/p2.pl';

die "(E) '$cmd' does not exist!\n" if !-e $cmd;

print "(I) Executing: $cmd\n";

if ( system( $cmd ) == 0 ) {
    print "(I) '$cmd' completed successfully.\n";
}
else {
    my $err_msg = "(E) failed to execute: $cmd\n";
    warn $err_msg;
    killBuild( $err_msg );
    exit 1;
}

__END__

My result:

(I) Executing: /tmp/p2.pl
Hello World!
(I) '/tmp/p2.pl' completed successfully.

[baxy77bax]

well if the stdout is something you can,t live without. one way to overcome this problem is piping the stdout from p2 to p1 and then printing it directly to screen like:

open (STDIN,"perl p2.pl|") || die "$!";
while(<STDIN>){
  print $_;
}

or if it is something small that p2 produces you can capture it with

my $capture = qx($Cmd); 
print $capture . "\n";

and print it