[Tutor] shebang problem

[Carlos Hanson]

On Sat, November 4, 2006 4:11 pm, Brian van den Broek wrote:
> Hi all,
>
> I'm still getting comfortable with Linux and this might be an OS
> rather than a python problem.
>
> I am trying to make a script directly executable. I've reviewed the
> 2nd ed of the Nutshell, and I cannot work out what I'm doing wrong.
> I'm running ubunutu 6.10 (edgy eft). Here's a copy past of my command
> line:
>
> brian at gottlob:~/test$ which python
> /usr/bin/python
> brian at gottlob:~/test$ ls -la shebangtest.py
> -rwxr-xr-- 1 brian brian 68 2006-11-04 02:29 shebangtest.py
> brian at gottlob:~/test$ cat shebangtest.py
> #!/usr/bin/python
>
> if __name__ == '__main__':
>
>      print "It works"
> brian at gottlob:~/test$ shebangtest
> bash: shebangtest: command not found
> brian at gottlob:~/test$ shebangtest.py
> bash: shebangtest.py: command not found
>
> I've also tried:
>
> #!/usr/bin python
>
> as my shebang line.
>
> I've been unable to get this to work. Clearly, there is something I've
> misunderstood. (`#!' is not an easy thing to google for :-)
>
> Best,
>
> Brian vdB
>

Your answer lies in the file permission.  The file needs to be
executable.  If you look at the man pages for chmod, you will find
your answer.

The shebang line tells the shell what to use to run the script.  For
example, if the file is not executable, you would execute it as
follows:

$ python shebangtest.py

As you found with `which python`, python is in /usr/bin, so executing
the script is actually

$ /usr/bin/python shebangtest.py

Therefore, the shebang line needs to be as follows:

#! /usr/bin/python

Then once the script has execute permissions (man chmod), it will run
as expected.

-- 
Carlos Hanson
Web and System Administrator
Tigard-Tualatin School District
503.431.4053