Fork

From Rosetta Code
Task
Fork
You are encouraged to solve this task according to the task description, using any language you may know.

In this task, the goal is to spawn a new process which can run simultaneously with, and independently of, the original parent process.


Perl

Interpreter: Perl 5.x

In the child code, you may have to re-open database handles and such.

FORK:
if ($pid = fork()) {
    # parent code
} elsif (defined($pid)) {
    setsid; # tells apache to let go of this process and let it run solo
    # disconnect ourselves from input, output, and errors
    close(STDOUT);
    close(STDIN);
    close(STDERR);    
    # re-open to /dev/null to prevent irrelevant warn messages.
    open(STDOUT, '>/dev/null');
    open(STDIN, '>/dev/null');
    open(STDERR, '>>/home/virtual/logs/err.log');
    
    # child code
    
    exit; # important to exit
} elsif($! =~ /emporar/){
    warn '[' . localtime() . "] Failed to Fork - Will try again in 10 seconds.\n";
    sleep(10);
    goto FORK;
} else {
    warn '[' . localtime() . "] Unable to fork - $!";
    exit(0);
}

Obviously you could do a Fork in a lot less lines, but this code covers all the bases

Python

Interpreter: Python 2.5

import os

pid = os.fork()
if pid > 0:
 # parent code
else:
 # child code