Test for root.

[Matt Alexander]

On Thu, 6 Sep 2001, Matt Alexander wrote:

> On Thu, 6 Sep 2001, Carl Parrish wrote:
>
> > Okay I'm writting a script that tests for root status. like so
> >
> > |
> >
> > test `whoami` = 'root' || echo "You must be root to execute the commands."
> >
> > it never seems to be able to pass the test. From the command line I can run whoami and get back root but it never works in the script.
> > Any idea what I'm doing wrong?
>
>
> I don't see anything wrong with what you have above, but I want to caution
> you about using this as a test for anything important.  Consider this:
>
> I create a shell script called "whoami" and place it in $HOME/bin.
> My new-and-improved "whoami" script contains the following:
>
> #!/bin/sh
> echo root
>
> Then I change my $PATH, like this:
> PATH=$HOME/bin:$PATH
>
> Now when I run your script, the test for whoami will return root.  Most
> likely your script would require root to run whatever following commands
> you might have and that you added this line just to notify people that
> they can't successfully procede.  In any case, be careful when you're
> writing shell scripts.
> ~M

P.S.  You should also get in the habit of specifying the full path to any
programs you use in your shell scripts.  So in the above test, use
/usr/bin/whoami instead of just whoami.