code that send a process to the background

feetyouwell · 09-20-2004, 08:35 PM

What function in C that sends a process to the background?

foo_bar_foo · 09-20-2004, 09:28 PM

check out sys/resource.h.
there are a few functions in there dealing with this but the others deal with classes of processes

int nice (int increment);

returned failure is -1
otherwise it returns new nice value
only root processes can lower nice but any thing can raise it (send itself further into background)
default value is 0
the spread of values is set by the kernel but generally
20 is most toward background (or 10)
PRIO_MIN/PRIO_MAX is the spread
negative values are less nice

itsme86 · 09-20-2004, 09:58 PM

Code:

/* Jump into background */
  if(fork())
    exit(0);
  setpgrp();

Hko · 09-21-2004, 05:53 PM

To make a program go really into background, i.e. become a "daemon", you can just call deamon() (see "man 5 daemon")

Code:

#include <stdio.h>
#include <unistd.h>

int main()
{
    if(daemon(0,0) < 0) {
        perror("");
        return 1;
    }

    /* ... */

    return 0;
}

Note that this makes it the program go into background to never come back. It completely detaches from the terminal, and looses stdin, stdout and stderr. It's not what the shell does when ending a command with "&". (or was it that what you were looking for?)

ibrahimhab · 11-29-2010, 03:11 PM

hello
pleaze can help me how to send process from frontground to background
and stop by using ctrl+z pleace i need code in
languge c

dugan · 11-29-2010, 03:20 PM

http://www.gnu.org/software/libc/man...and-Background