Why doesn't this work in bash?

dyscoria · 2008-03-11 15:10:44

OK, just started learning how to write bash scripts, but i'm a little stumped.

touch script
chmod u+x script
vim script

And inside:

#!/bin/bash
cd $1

Running "./script /home" doesn't seem to do anything (aim here is to change directories with the script).

As I understand it, $1 will take the first argument passed when running the script. This works fine if I replace 'cd' in the script with 'echo', which will just echo back whatever argument I passed alongside. Is there something different I need to do for changing directories.

Cerebral · 2008-03-11 15:13:27

When you run the script, it'll run a new instance of bash. Inside the new instance, it'll change directories. Then the script ends, the new instance of bash terminates, and the shell you ran the script from is back where you started.

If you use

#!/bin/bash
cd $1 
echo $(pwd)

You'll see it does actually change directories.

dyscoria · 2008-03-11 15:16:36

Awesome. Cheers bud!

*overcomes first hurdle*

danielsoft · 2008-03-11 15:55:38

and there's more: if you want to run a script in the current instance of bash, use the "source" command

[danny@zdroj ~]$ cat cd-script
#!/bin/bash
cd /tmp
[danny@zdroj ~]$ ./cd-script 
[danny@zdroj ~]$ pwd                
/home/danny
[danny@zdroj ~]$ source ./cd-script 
[danny@zdroj tmp]$ pwd
/tmp
[danny@zdroj tmp]$

dyscoria · 2008-03-11 16:10:05

That might come in very hand actually...

Cheers!

* now understands why changes to ~/.bashrc require sourcing in ALL open xterms *

Arch Linux

#1 2008-03-11 15:10:44

Why doesn't this work in bash?

#2 2008-03-11 15:13:27

Re: Why doesn't this work in bash?

#3 2008-03-11 15:16:36

Re: Why doesn't this work in bash?

#4 2008-03-11 15:55:38

Re: Why doesn't this work in bash?

#5 2008-03-11 16:10:05

Re: Why doesn't this work in bash?

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