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I have a Bash script that needs to be run from an interactive prompt, due to environment variables and configuration that only seems to be read when actually logged into a session. Examples below:

Good

me@client:~$ ssh box
user@box:~$ /usr/local/bin/myscript

Bad

me@client:~$ ssh box "/usr/local/bin/myscript"

Is there any Bash-fu that I can use in my script to determine if it's being run via a one-line SSH command?

Craig Watson
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1 Answers1

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You could just check whether there is a terminal connected to standard input (that's what the tty command does). Add these lines to your script:

if ! tty >/dev/null; then
    echo "Must be run from a tty"
    exit 1
fi

Your script will now exit with an error unless run correctly:

$ ssh badabing ~/scripts/a.sh
Must be run from a tty

$ ssh badabing
terdon@badabing ~ $ ~/scripts/a.sh
Works!
terdon
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    In this case, OP's script probably wants ~/.profile etc. to be read. – muru Feb 04 '16 at 14:19
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    @muru yes, I know, and had even written a first draft of this answer suggesting they just add . ~/.profile to the script, but that could cause other problems. For example, what if ~/.profile sources .bashrc and .bashrc sources a third file that sets up the environment? In that case, assuming the .bashrc is exiting on non-interactive shells, the same problem would occur. It's probably worth posting an answer suggesting the OP source whatever files are necessary but I felt this was both cleaner and actually answers the question asked. – terdon Feb 04 '16 at 14:22