$pid=open3( *wr1, *rd1, *er1, "C:\\Programme\\service.exe" );
sleep 3;

close(wr1);
local($/) = undef;
close(rd1);
close(er1);
  
waitpid $pid, 0;
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Very nice! Worked like a charm.

Blasphemy time ... why not just write a shell command instead of a Perl script for this? For example, here is what i use to restart our mod_perl enable web server for Krang:

/usr/local/krang/bin/krang_ctl stop
sleep 2
/usr/local/krang/bin/krang_ctl start
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UPDATE: oh uh ... i see now that i got your order backwards ... start, wait, then stop. I'd still be tempted to solve this with a shell script rather than Perl, because you are dealing mostly with shell commands. One naive solution would be to grep for the process, but i'm sure there is a better way to capture the PID and stop it. Perhaps if you wrote some wrapper script like the apachectl script that keeps track of its PID. It writes the PID to a file and reads that file when you need to stop it. You could write the wrapper in Perl and have it accept two args: start and stop -- then use a shell script to call the Perl script.

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Thanks for the quick response but.. well, is there a way to do that for tor? That's what I'm trying to do. My real script of course does stuff more complex than waiting ten seconds. :)

UPDATE: Tor can be installed as a windows service, so I guess this question boils down to, how do I start a windows service, wait a bit, and stop it. Any ideas?

ahhh, well next time you should mention that your script does more than sleep 10 sec...otherwise you will get an answer to what you've asked (simple and straight to the point....)

REM batch file method:
net start my_service
perl -e "sleep 10"
net stop my_service

# perl method:
system("net start my_service");
sleep 10;
system("net stop my_service");
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& is specific to unix shells. The Windows shell equivalent is start:

my $result = system("start C:\\Programme\\service.exe");
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Unforunately, start doesn't return the process id, so it's not too useful to you. It might be useful to other readers of this thread, though.

Indeed, thanks for clarifying that. Does no process id mean I can't stop the process without dying, as I would guess is the case?

It means you can't stop the process (with or without dying). To kill a process, you need to kill it, and kill requires the PID of the process to kill. See my other reply for working (tested) solution to your problem.

use strict;
use warnings;
use IPC::Open3;
#my $result = system("C:\\Programme\\Tor\\tor.exe &");
#print "sleeping";
#sleep(3);

my ($WR1, $RD1, $ER1);

my $tor_fhs = {};
my $pid = start_tor($tor_fhs);
sleep 1;
stop_tor($tor_fhs);

sub start_tor {
    my $tor_fhs = shift;
    open3( $tor_fhs->{wr}, $tor_fhs->{rd}, $tor_fhs->{err}, "C:\\Progr
+amme\\Tor\\tor.exe" );
    print "tor started\n";
    return $pid;
}

sub stop_tor {

    my $tor_fhs = shift;
    close($tor_fhs->{wr});
    local($/) = undef;
    close($tor_fhs->{rd});
    #close($ER1);
    print "tor stopped\n";  
}
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You're missing the

waitpid $pid, 0;
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That's why your processes don't get stopped properly..... Update:
Tried it without the 'waitpid' and exactly as predicted left me with "ghost" processes which I had to kill manually...

You never kill the process, so it never dies.

use strict;
use warnings;

sub start {
    my $pid;

    {
        # We don't need to talk to the process,
        # So we don't need open3.

        # Close communication channels.
        local *STDIN;
        local *STDOUT;
        local *STDERR;

        # Launch child process.
        $pid = eval { system 1, @_ }; # 1 == P_NOWAIT
    }

    die("Can't spawn-NOWAIT: $!\n")
        if !$pid || $pid < 0;

    return $pid;
}


sub stop {
    my ($pid) = @_;
    kill(15, $pid) and waitpid($pid, 0);
}


# Arguments to the program must be passed in seperate function args
# For example,
#
#   my $tor_pid = start('C:\\Programme\\service.exe', 'arg1', 'arg2');
# 
# If you don't, you'll get the PID of the shell that's created
# to launch the program, and stop() won't work.

my $tor_pid = start('C:\\Programme\\service.exe');
print "tor started\n";  
sleep 3;
stop($tor_pid);
print "tor stopped\n";
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Maybe the idea in this snippet can help: "Portable IPC::Open3 timeout"

rem this is a DOS batch file

net start SERVICENAME
perl -e 'sleep 10'
net stop SERVICENAME
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