Auto confirm EULA in bash script

I am writing a bash script that is supposed to do some confirmation and also install software. F开发者_运维知识库irst step of the installation process is that I am being asked to confirm the EULA and type 'yes'. Is there a way to get the 'yes' in there from the bash script?

The command yes outputs a never-ending stream of a specified string, or y if unspecified.

$ yes | head
y
y
y
y
y
y
y
y
y
y
$ yes yes | ./interactive-installer  # something like this?

sometimes you can use

echo "yes"|./interactive-installer

Expect may be of help there. I've never used it myself, but I understand that it allows you to specify pre-programmed responses to specific prompts.

Use read.

#!/bin/sh

echo -n "Confirm? (y/n):"
read confirm_val

if [[ "$confirm_val" == "y" ]] ; then
  echo "Confirmed!"
else
  echo "Not confirmed!"
fi

#!/bin/sh

echo -n "Confirm me ? (yes/no):"
read choice

if [ "$choice" ==  "yes" ] ; then
        echo "Confirmed!"
else
        echo "Not confirmed!"
fi