topic Re: forking a new process in Operating System - HP-UX

forking a new process

siaemic — Wed, 09 Oct 2002 08:52:48 GMT

Inside a C program, how can I launch a new application and let it running even if parent process die without becoming a zombie?
Does the new application get a parent pid equal to 1 ?

Re: forking a new process

harry d brown jr — Wed, 09 Oct 2002 10:10:19 GMT

man exec

live free or die
harry

Re: forking a new process

Rainer von Bongartz — Wed, 09 Oct 2002 10:39:40 GMT

Choose one of the following

execl(), execle(), execlp(), execv(), execve(), execvp()

Regards
Rainer

Re: forking a new process

Dietmar Konermann — Wed, 09 Oct 2002 15:45:40 GMT

I usually do things like this...

[...]

if (signal (SIGCHLD, SIG_IGN) == -1)
perror("signal");

if ( (pid = fork()) < 0)
perror("fork");
else if (pid == 0) { /* child */
setsid(); /* become leader */
execlp ("cmd", "arg0", "arg1", (char*) 0); /* run your prg */
perror ("execlp");
}

[...]
/* parent continues */

Re: forking a new process

Wodisch — Wed, 09 Oct 2002 19:35:52 GMT

Hi,

in addition you'll have to set the SIG_CHLD to *ignore* BEFORE you call "fork(2)"!

HTH,
Wodisch

Re: forking a new process

Dietmar Konermann — Thu, 10 Oct 2002 06:19:29 GMT

Hmm, Wodisch.... do I miss something? I call signal() before fork()ing.

Re: forking a new process

Wodisch — Thu, 10 Oct 2002 15:02:21 GMT

Dietmar,

you are right - and I was blind :-(