in reply to IPC problem

I think you don't want WNOHANG here... At least, with waitpid($pid,0) it does what I'd expect it to do.  Sample output: 

Process spawned with PID = 24247 
HELP_VALUE is 24247
ExitCODE is 2 
Process spawned with PID = 24248 
HELP_VALUE is 24248
ExitCODE is 1

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Re^2: IPC problem
by gyre007 (Novice) on Oct 18, 2007 at 13:32 UTC
    Maybe it is a bug of Perl...because I changed the script as you suggested and still get the same result :( 
    Process spawned with PID = 16921
HELP_VALUE is 16921
ExitCODE is 2
Process spawned with PID = 16922
HELP_VALUE is 16922
ExitCODE is 2

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[d/l]

      Hm, maybe. What version of Perl / IPC::Open3? What platform?  I can't reproduce the problem here (5.8.8 / 1.0106, Linux), so we'll have to wait until someone else can...

      You have changed waitpid($pid2,0) too, have you? (which is what I implied, but didn't explicitly say)  (the problem with WNOHANG is that the process might not yet have terminated at that point, so you wouldn't get a valid return code).

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        (SunOS calcium 5.8 Generic_108528-23 sun4u sparc SUNW,UltraAX-i2///This is perl, version 5.005_03 built for sun4-solaris) Yes I have changed the code as You said... 
        #!/usr/bin/perl

use IPC::Open3;
use POSIX qw( :sys_wait_h );

my $pid;
my $cmd = "new.pl";
my $cmd2 = "new2.pl";
my $exit_code = 0;
my $exit_code2 = 0;
my $help = 0;
my $help2 = 0;

print "\n*******SPAWNING FIRST PROCESS**********\n";
$pid = open3(*MMRET_IN, *MMRET_OUT, *MMRET_ERR, $cmd);
print "Process spawned with PID = $pid \n";
$help = waitpid($pid,0);
print "HELP_VALUE is $help\n";
$exit_code = $? >> 8;
print "ExitCODE is $exit_code \n";
print "Return_Value \$\? = $? \n";

print "\n*******SPAWNING SECOND PROCESS********\n";
$pid2 = open3(*MMRET_IN2, *MMRET_OUT2, *MMRET_ERR2, $cmd2);
print "Process spawned with PID = $pid2 \n";
$help2 = waitpid($pid2,0);
print "HELP_VALUE is $help2\n";
$exit_code2 = $? >> 8;
print "ExitCODE is $exit_code2 \n";
print "Return_Value \$\? = $? \n";
print "********************************\n\n";

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[d/l]
        Yes, I have cahnged it as you suggested... Btw... SunOS 5.8 Generic_108528-23 sun4u sparc SUNW,UltraAX-i2 /// This is perl, version 5.005_03 built for sun4-solaris 
        #!/usr/bin/perl

use IPC::Open3;
use POSIX qw( :sys_wait_h );

my $pid;
my $cmd = "new.pl";
my $cmd2 = "new2.pl";
my $exit_code = 0;
my $exit_code2 = 0;
my $help = 0;
my $help2 = 0;

$pid = open3(*MMRET_IN, *MMRET_OUT, *MMRET_ERR, $cmd);
print "Process spawned with PID = $pid \n";
$help = waitpid($pid,0);
print "HELP_VALUE is $help\n";
$exit_code = $? >> 8;
print "ExitCODE is $exit_code \n";

$pid2 = open3(*MMRET_IN2, *MMRET_OUT2, *MMRET_ERR2, $cmd2);
print "Process spawned with PID = $pid2 \n";
$help2 = waitpid($pid2,0);
print "HELP_VALUE is $help2\n";
$exit_code2 = $? >> 8;
print "ExitCODE is $exit_code2 \n";

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        Dunno...
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[d/l]
      And maybe it's the problem of my scripts "external.pl" and "external2.pl" here they are: external.pl: 
      #!/usr/bin/perl

my $i =0;
while($i<=1000000){
  if($i == 800){
    exit 2;    
  }
  $i++;
}

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      external2.pl: 
      #!/usr/bin/perl

my $i =0;
while($i<=1000000){
  if($i == 900){
    exit 1;    
  }
  $i++;
}

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      Or I don't know what can cause these problems then...
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[d/l]
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