Shell Scripts Answering Prompts

dudeman41465 · 01-24-2006, 11:05 AM

I'm still a newb at writing shell scripts. I've figured out enough to make them run commands to automate things but I have a question. If I know a command will be met with a prompting question (password, yes or no to install dependancies, etc.) could I write in the script how to go about answering such prompts so if I were to run a long script it would automatically answer the questions for me?

macemoneta · 01-24-2006, 11:20 AM

Yes, but you'll need to use a different language to write the script, like TCL/Expect. For example:

#!/usr/bin/expect -f
# wrapper to make passwd(1) be non-interactive
# username is passed as 1st arg, passwd as 2nd
set password [lindex $argv 1]
spawn passwd [lindex $argv 0]
expect "assword:"
send -- "$password\r"
expect "assword:"
send -- "$password\r"
expect eof

If you Google for TCL/Expect, you'll find loads of resources. Creating simple responses is really very straight forward.