Thread: An Autonomous Child Process

what part of the "fork/exec" part is it that you are not happy with. Perhaps your forked process needs to "untie" itself from the main process?

Edit: Look at the setsid() and setpgrp() system calls.

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Mats

Call fork()
Then in the child, call exec()

Hi,
Above all, let me thank you for the rapid responses.
I regret to say however, that I wasn't able to successfully implement what you had suggested.
I mean, I've already attempted to "fork" then "exec", but in vain.
I was hoping that, should this not burden you too heavily, to place a snippet as an example, supposing that the two executables are "a.o", and "b.o"...
Thank you,
Thanks again,
Daniel

Post an example.

Do something like this

Code:

void functionToDoWhatever(void);

main(){

int pid;

printf("this is my main process");

printf("I will now make a child process that is totally independent from the main(parent) process");

pid = fork();

if (pid == 0)
functionToDoWhatever();

else
printf("fork failed. Child process could not be created");



}


void functionToDoWhatever(){

print("im the functionToDoWhatever, and I run inside a child process that is independent from the main(parent) process");

//put whatever code you want in here to do whatever you want.

}

pid holds the return value of fork which is an int. If it is zero then a child proces was created successfully, otherwise there was an error. If pid is zero then it was successful and the function functionTODoWhatever() will run in your child while your main function still runs.

If im wrong someone correct/modify what im saying. I think im pretty close to how a fork() works.

So the posted code does not actually assign pid with the result of fork().

And fork returns TWO values (well, one value to the parent process, and another to the child process). The parent process receives the child process id, the child process receives a zero value, and if it's LESS THAN ZERO, it is an error. So you probably need an if-else if-else to determine if it is the child or parent and if the parent got a success or fail (I don't believe there is an option of a child being produced if there is a failure).

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Mats