Hi,

In terms of the implementation, your script would want to parse line-by-line whatever is piped in to it, and then act based on what it got. The format I've used in general for scripts that run in this way (input is directly piped into them) is:

Code:

#!/bin/bash
/bin/cat - | while read -r line
do
        #Code goes here
done

The point of /bin/cat - at the start is just to print out again whatever is passed into cat as standard input (represented by the - symbol), which will be whatever Postfix is piping into the script. So you can then do whatever you wan to do with each line to determine what it is, what to do with it, and so on.

So in your case, if you had lines that would define and set variables, you could look for them on a line-by-line basis. A quick example of one way of doing this would be the following.

Let's say our e-mail body will contain the following variables: UID, USERNAME and HOMEDIR. We want our script to find these matching lines, and assign the variables it reads in. Finally we'll terminate our message body with a single line reading END, and get the script to write out the variables it's read at that point.

Here's our code:

Code:

#!/bin/bash
/bin/cat - | while read -r line
do
        case "$line" in
                UID=*)
                        uid=`echo "$line" | /usr/bin/awk -F= '{print $2}'`
                        ;;
                USERNAME=*)
                        user=`echo "$line" | /usr/bin/awk -F= '{print $2}'`
                        ;;
                HOMEDIR=*)
                        home=`echo "$line" | /usr/bin/awk -F= '{print $2}'`
                        ;;
                END)
                        echo "The UID is $uid, the username is $user, and the homedir is $home"
                        exit 0
                        ;;
        esac
done

Here's our example input:

Code:

UID=1002
USERNAME=unixforum
HOMEDIR=/home/unixforum
END

And here's what happens when we run the script by piping the contents of our example input into it:

Code:

$ cat example.txt | ./script.sh
The UID is 1002, the username is unixforum, and the homedir is /home/unixforum
$

Hope this gives you an idea of how the implementation would work, and how your approach of reading in and assigning variables to work with might look.