Question

I am a bit of a newbie on Python, but was was testing some things I learned on Ubuntu.
Basically, this script is supposed to set your TCP/IP config, then restart the networking daemon and display the changes.

This is the whole script:

#!/usr/bin/env python
import commands
import os
import sys

euid = os.geteuid()
if euid != 0:
    print "Script not started as root. Running sudo.."
    args = ['sudo', sys.executable] + sys.argv + [os.environ]
    # the next line replaces the currently-running process with the sudo
    os.execlpe('sudo', *args)

print 'Running. Your euid is', euid

print "IP"
IP = raw_input(">>")
print "Gateway"
PE = raw_input(">>")

ifconfig = commands.getoutput("ifconfig")
interfaz = ifconfig[0:5]

ArchivoInterfaces = open("/etc/network/interfaces", "w")
ArchivoInterfaces.write("#auto lo\n#iface lo inet loopback\nauto %s\niface %sinet static\naddress %s\ngateway %s\nnetmask 255.255.255.0"%(interfaz, interfaz, IP, PE))
ArchivoInterfaces.close()

ArchivoResolv = open("/etc/resolv.conf", "w")
ArchivoResolv.write("# Generated by NetworkManager\ndomain localdomain\nsearch localdomain\nnameserver 8.8.8.8\nnameserver 8.8.4.4")
ArchivoResolv.close()
os.execlpe('/etc/init.d/networking', "test","restart", os.environ)
print "Todo esta correcto, su IP ahora es %s" %(IP)
fin = raw_input("write d and press enter to show the changes, or press enter to exit.")

if fin == "d":
    ArchivoResolv = open("/etc/resolv.conf")
    ArchivoInterfaces = open("/etc/network/interfaces")
    ifconfig2 = commands.getoutput("ifconfig")
    print "ARCHIVO resolv.conf\n"+ArchivoResolv.read()+"\n\n"+"ARCHIVO interfaces\n"+ArchivoInterfaces.read()+"\n\n"+"RESULTADO DE \"ifconfig\"\n"+ifconfig2
    fin = raw_input("Presiona ENTER para salir.")

Unfortunately, it keeps stopping on this line – and I’m not sure why:

os.execlpe('/etc/init.d/networking', "test","restart", os.environ)

After reaching this spot, the script runs the restart, and then just exits.

I would love to get it to run the last part of the script so I can see what changed, but I’m unable. Any ideas?

Answer 1

Because all of the exec family of functions work by replacing the current process with the one you execute.

If you just want to run an external command, use the spawn functions instead. (In this case, os.spawnlpe is very nearly a drop-in replacement.)