macos - Changing PS1 prompt in a Bash parent shell

Question

Using a script, I was to change the prompt of the parent Bash shell. I have tried the following:

PS1="Hello World > "

This changes the prompt of the subshell, which the script is running in, but which command would I use to change the prompt of the parent shell. Any ideas?

Answer 1

In all cases the parent shell must cooperate. The child process in a unix environment cannot influence the parent process without its cooperation.

Try this in the subshell script changePrompt.sh:

echo 'PS1="Hello World > "'

And then call the script from the parent shell like this:

eval "$(changePrompt.sh)"

Or, a different approach: Source the script instead of calling it. changePrompt.sh:

PS1="Hello World > "

Call it like this:

source changePrompt.sh

or simply:

. changePrompt.sh