Getting the pid of the process launched by my perl program

[Anonymous Monk]

Hi PERL Monks,

I'd like to get the process id of the background process launched from within my perl program. I'm trying to do this in my perl code -

system (./a.out &);

I want know the process id of the newly lauched process "a.out". I can get this in a C shell script -

./a.out &
echo $! > /tmp/pidfile

How will I do this in perl ? Also, I don't want to call the C shell script from the perl program.

What do I do ??

thanks in advance !!

[edan]

$SIG{CHLD} = 'IGNORE'; # on systems where it's supported

defined( my $pid = fork ) or die "fork: $!";

if ( $pid )
{
    # parent
    print "child pid is $pid\n";
}
else
{
    # child
    exec("a.out") or die "exec: $!";
}

[Anonymous Monk]

Thanx much edan and ozone !!

[Anonymous Monk]

I'm using the same logic to monitor the child process with a timer in the parent. On maximum timeout I'm killing the child process. The issue is I'm running an exe from the child which doesn't die on kill the child. I tried to explicitly kill the process with taskkill on windows and it works fine. But I face portability issues because of using taskkill. Can anybody help on this?

[ozone]

The current process id is stored in $$, but I suspect that what you're trying to do is find out when the background process has died, right? If so, you'd be better off using fork(), exec() and waitpid.

A quick search produced a helpfull node that could help: ForkMe