fork
fork - create a new process just like this one
fork
Does a fork(2) system call.  Returns the child pid to the parent process
and 0 to the child process, or 
undef
 if the fork is unsuccessful.
Note: unflushed buffers remain unflushed in both processes, which means
you may need to set 
$|
 ($AUTOFLUSH in English) or call the 
autoflush()
 FileHandle method to avoid duplicate output.
If you 
fork()
 without ever waiting on your children, you will accumulate
zombies:
    $SIG{CHLD} = sub { wait };
There's also the double-fork trick (error checking on 
fork()
 returns omitted);
    unless ($pid = fork) {
        unless (fork) {
            exec "what you really wanna do";
            die "no exec";
            # ... or ...
            ## (some_perl_code_here)
            exit 0;
        }
        exit 0;
    }
    waitpid($pid,0);
See also 
the perlipc manpage
 for more examples of forking and reaping
moribund children.