I work with Amazon Linux instances and I have a couple scripts to populate data and install all the programs I work with, but a couple of the programs ask:
Do you want to continue [Y/n]?
and pause the install. I want to auto answer "Y" in all cases, I'm just now sure how to do it.
Although this may be more complicated/heavier-weight than you want, one very flexible way to do it is using something like Expect (or one of the derivatives in another programming language).
Expect is a language designed specifically to control text-based applications, which is exactly what you are looking to do. If you end up needing to do something more complicated (like with logic to actually decide what to do/answer next), Expect is the way to go.
You might not have the ability to install Expect on the target server. This is often the case when one writes, say, a Jenkins job.
If so, I would consider something like the answer to the following on askubuntu.com:
https://askubuntu.com/questions/338857/automatically-enter-input-in-command-line
printf 'y\nyes\nno\nmaybe\n' | ./script_that_needs_user_input
Note that in some rare cases the command does not require the user to press enter after the character. in that case leave the newlines out:
printf 'yyy' | ./script_that_needs_user_input
For sake of completeness you can also use a here document:
./script_that_needs_user_input << EOF
y
y
y
EOF
Or if your shell supports it a here string:
./script <<< "y
y
y
"
Or you can create a file with one input per line:
./script < inputfile
Again, all credit for this answer goes to the author of the answer on askubuntu.com, lesmana.
You just need to put -y with the install command.
For example: yum install <package_to_install> -y
If you want to just accept defaults you can use:
\n | ./shell_being_run
echo y | command should work.
Also, some installers have an "auto-yes" flag. It's -y for apt-get on Ubuntu.
Source: Stackoverflow.com