temporary setting the path in an “init” file

Question

I have an "init" file that reads

#!/bin/sh

export PATH=$PATH:/home/me/morph_numsys/software/bin

by which I'd just like to set the path to that folder for only this bash session. However, when I execute the script, sh init, it still doesn't recognize the path. However, if I just say export PATH=$PATH:/home/me/morph_numsys/software/bin, then it works fine. Any ideas how I can do this?

I'm on ubuntu and xterm.

Answer 1

When you say "for only this bash session", I assume you mean the bash session that is calling the script.

When you execute your script, it gets a new shell environment. Thus when you export variables, you are exporting it to the new shell environment and not its parent environment. As far as I know, there is no way to access the parent environment. However, since you are using bash, there may be a few solutions:

Use source

Rather than execute the script like this: /path/to/init.sh do source /path/to/init.sh

From the bash man page:

source filename [arguments]

Read and execute commands from filename in the current shell environment and return the exit status of the last command executed from filename.

Make your script a shell function and put it in .bashrc

Another option is to make init a function and put it in .bashrc like this:

function init {
    export PATH=$PATH:/home/me/morph_numsys/software/bin
}

Then from the terminal you can just run init.