Better handling of KeyboardInterrupt in cmd.Cmd command line interpreter

Question

While using python\'s cmd.Cmd to create a custom CLI, how do I tell the handler to abort the current line and give me a new prompt?

Here is a minimal example:

Answer 1

Instead of using signal handling you could just catch the KeyboardInterrupt that cmd.Cmd.cmdloop() raises. You can certainly use signal handling but it isn't required.

Run the call to cmdloop() in a while loop that restarts itself on an KeyboardInterrupt exception but terminates properly due to EOF.

import cmd
import sys

class Console(cmd.Cmd):
    def do_EOF(self,line):
        return True
    def do_foo(self,line):
        print "In foo"
    def do_bar(self,line):
        print "In bar"
    def cmdloop_with_keyboard_interrupt(self):
        doQuit = False
        while doQuit != True:
            try:
                self.cmdloop()
                doQuit = True
            except KeyboardInterrupt:
                sys.stdout.write('\n')

console = Console()

console.cmdloop_with_keyboard_interrupt()

print 'Done!'

Doing a CTRL-c just prints a new prompt on a new line.

(Cmd) help

Undocumented commands:
======================
EOF  bar  foo  help

(Cmd) <----- ctrl-c pressed
(Cmd) <------ctrl-c pressed 
(Cmd) ddasfjdfaslkdsafjkasdfjklsadfljk <---- ctrl-c pressed
(Cmd) 
(Cmd) bar
In bar
(Cmd) ^DDone!