An example of playing with fork+exec in python. Basically, when there's a non-zero exit, we can format the output nicely. Otherwise, the parent and child exist in the same process group, tty, etc. so the user is just interacting with the child

gistfile1.py

#!/usr/bin/env python

# Just a quick demonstration of using fork+exec and watching the exit
# status of the sub-command to demonstrate that this will work with kcs

import sys
import os
import select
import signal

def handle_child(cmdline):
    os.execvp(cmdline[0], cmdline)
        
def simple_fork(cmdline):
    def handle_parent_simple(cmdline):
        pid, status = os.wait()
        if status != 0:
            sys.stderr.write("\nPID {0} exited {1} trying to execute:\n  {2}\n".format(pid, status, cmdline))
        sys.exit(status)
    
    pid = os.fork()
    if pid != 0: # parent
        handle_parent_simple(cmdline)
    else:
        handle_child(cmdline)

def main(args = sys.argv):
    simple_fork(sys.argv[1:])

if __name__ == '__main__':
    main()