Re: [tlug] question about shell scripting

[Curt Sampson <cjs@example.com>]

On Thu, 25 Jan 2007, scott@example.com wrote:

> So first I get a list of users:
>
>   awk -F: '{ print $1 }' /etc/shadow

In general, you'd want to use /etc/passwd; isn't /etc/shadow readable
only by root? Though it probably doesn't matter in this case, since you
no doubt need to be root to run your particular script.

> which is OK. However if I want to use backticks and do something like this:
>
>   crontab -l -u `awk -F: '{ print $1 }' /etc/shadow`
>
> it crashes. I'm guessing that the output of that awk is a stream instead
> of a list of individual names with a line break.

It's a list of names separated by whitespace.

> I thought maybe I could
> write a for statement in a script this way:
>
>   #!/bin/bash
>   for x in `awk -F: '{ print $1 }' /etc/shadow`;
>   /usr/bin/crontab -l -u $x;
>   done

You forgot a do, from the looks of it. This works for me:

    for i in $(awk -F: '{print $1}' /etc/passwd); do
	echo $i
    done

cjs
--
Curt Sampson       <cjs@example.com>        +81 90 7737 2974