bash - How to detect if a script is being sourced

Question

I have a script where I do not want it to call exit if it's being sourced.

I thought of checking if $0 == bash but this has problems if the script is sourced from another script, or if the user sources it from a different shell like ksh.

Is there a reliable way of detecting if a script is being sourced?

Answer 1

If your Bash version knows about the BASH_SOURCE array variable, try something like:

# man bash | less -p BASH_SOURCE
#[[ ${BASH_VERSINFO[0]} -le 2 ]] && echo 'No BASH_SOURCE array variable' && exit 1

[[ "${BASH_SOURCE[0]}" != "${0}" ]] && echo "script ${BASH_SOURCE[0]} is being sourced ..."