changing current working dir with a script

You can't have your cake an eat it too. The two things happening here are executing a script in a new shell and importing lines of script to be run in the current shell. By using the dot operator (which is an alias for the source command) you are actually running the code in your current shell. If your code chooses to cd, when it's done you will be left in the new directory.

If on the other hand you want to execute a program (or script, it doesn't matter), that program will be launched as a sub-process. In the case of shell scripts a new shell will be opened and the code run inside it. Any cd action taken will change the current working directory for that shell, effective for any commands to follow. When the job finishes the shell will exit, leaving you back in your original (and unmodified) shell.

If it's something you use a lot and you want its effects to be left behind in your current shell, perhaps you could write your "script" as a shell function instead and save it in your ~/.profile or other shell rc file.

function cpj() {
    # code here
    cd /path/$1
    emacs file_name
}

I have similar script written for my personal use. There is a very easy trick to achieve change working directory inside a script. First just write your script, in.ex.:

#!/bin/bash

case $1 in
     project1) cd /home/me/work/customer1/project1
     ;;
     project2) cd /home/me/work/customer2/project1
     ;;
     project3) cd /home/me/work/customer3/project2
     ;;
     project4) cd /home/me/work/customer4/project5
     ;;
     *) echo "Usage: cdto cd_profile_name"
     ;;
esac

Now lets assume the script is called 'cdto'. To make it working you have to source it in the current shell, what can be achieved by 'source' or '.' command (both are the same). In ex.:

. cdto project1

Now to make it more convenient:

1. Copy 'cdto' script to a 'bin' directory of your account (in. ex. /home/johnsmith/bin - create it if not exists). Check your PATH variable to ensure the 'bin' directory is included:

   echo $PATH

If not, edit your .profile file and add:

if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

2. Add an alias to your .bashrc or .bash_aliases file:

   alias cdto='. cdto'

And it's done. After next login or when you open a new terminal you could just use in.ex.:

cdto project1

Enjoy :-)

Sebastian Piech