Spawns a child process that executes the code immediately
fork call until the process is
terminated (usually with an
exit). The child process
runs parallel to the parent process and
shares all the parent's variables and open filehandles.
The function returns the child pid to the parent process and
0 to the
child process on success. If it fails, it returns the undefined value to the
parent process, and no child process is created. If you
fork your child processes, you'll have to
wait on their
zombies when they die. See the
wait function for more
fork function is unlikely to be implemented on any operating system
not resembling Unix, unless it purports POSIX compliance.