The flawed setup is as follows:
.bashrc
export PROMPT_COMMAND="my_custom_bash_prompt_script"
export PS1=""
This setup works fine from within an Emacs shell but from a "normal" shell, when I did an up arrow, the prompt itself would disappear!
The corrected setup is very similar:
.bashrc
function bash_command_function {
PS1=`my_custom_bash_prompt_script`
}
export PROMPT_COMMAND="bash_prompt_script"
Once I realized that I needed a bash function anyways (because you can't export something from a subshell to the super shell), I just inlined my rather simple script.
Keep in mind, if my_custom_bash_prompt_script ever returns anything with a % character in it, bash may interpret it, so you will need to escape the %s.
