How to give password in shell script?

Question

In a shell script file I am using some commands like scp and make install which ask for my password.

I run a shell script to compile a big project, and after some time it asks for my password for using scp. I need to wait for that process and give the password after that.

I just want to do it all by shell script without interaction, so how can I avoid being prompted for the password here?

Answer 1

Short answer: DON'T

Use public key authentication for SCP and sudo with NOPASSWD directive for make install

Answer 2

If you can't use ssh trust and must enter the password later on in your script, use read -s -p "Password:" USER_PASSWORD to silently read in the password. You can then export USER_PASSWORD to an expect script, avoiding it being displayed in ps:

    #!/usr/bin/expect -f
    spawn scp some.file USER@otherhost:~
    expect "assword:"
    send -- "$env(USER_PASSWORD)\r"
    expect eof

Answer 3

I think it's a better idea to generate an authentication key, and use this key based authentication instead of writing plain text passwords into your scripts.