Why doesn't "cd" work in a shell script?

Question

I'm trying to write a small script to change the current directory to my project directory: #!/bin/bash cd /home/tree/projects/java I saved this file as proj, added execute permission with `chmod`, and copied it to `/usr/bin`. When I call it by: `proj`, it does nothing. What am I doing wrong?

Answer 1

The 'cd' is working in your script and you can see it is so with:

#!/bin/bash

echo `pwd`

cd /home/tree/projects/java

echo `pwd`

The problem with this code is that when the script executes it is executing in a child(subshell) shell where the 'cd' succeeds and when the script ends you are returned to the parent shell and back to the directory in which you were originally in. To make it behave in the way you want you can call it as '. proj' and the script will execute in the current shell and not a subshell.

Answer 2

The 'cd' is working in your script and you can see it is so with:

#!/bin/bash

echo `pwd`

cd /home/tree/projects/java

echo `pwd`

The problem with this code is that when the script executes it is executing in a child(subshell) shell where the 'cd' succeeds and when the script ends you are returned to the parent shell and back to the directory in which you were originally in. To make it behave in the way you want you can call it as '. proj' and the script will execute in the current shell and not a subshell.