Question

I have a program that runs and asks users certain questions. I want to automate it so that every question is responded to with No.

Answer 1

yes no | <command>

Where <command> is the command you want to answer no to.

(or yes n if you actually need to just output an n)

The yes command, by default, outputs a continuous stream of y, in order to answer yes to every prompt. But you can pass in any other string as the argument, in order for it to repeat that to every prompt.

As pointed out by “just somebody”, yes isn’t actually standardized. While it’s available on every system I’ve ever used (various BSDs, Mac OS X, Linux, Solaris, Cygwin), if you somehow manage to find one in which it doesn’t, the following should work:

while true; do echo no; done | <command>

Or as a full-fledged shell script implementation of yes, you can use the following:

#!/bin/sh

if [ $# -ge 1 ]
then
    while true; do echo "$1"; done
else
    while true; do echo y; done
fi