Enter/Return command in Shell script

Question

I am trying to issue an external shell command via python script. The external command prompts user to type 'Y' and hit enter to proceed further. How do I write the command in python script in a loop so that it does not prompts the user in every loop. I can grab a coffee and step out instead of sitting in front of the PC and hit Y every time I see the prompt.

My python script loops like

<for loop:>
 os.system(<External Command>)

I tried echoing "Y\n" but did not work.

• Makoto: Well...if all you're doing is accepting input from the user, is there any reason not to do that through raw_input or input if you're on Python 3.x?

Answer 1

use the yes command, the following code should do what you want:

<for loop:>
 os.system('yes Y | <external command>')

more info here

Answer 2

Check out pexpect. You can write a script to watch for your command's output, and respond appropriately.