Shell Programming and Scripting

As part of an expect script, I have to convert a strange user ID to a conventional UNIX ID. To do this, I read the contents of a file and do a little awk magic. Here's that bit of the expect script:

Code:

send "awk 'NF == 10  && \$NF == strange_user_id {print \$(NF-2)}' file_with_my_info\r"
expect "\$ $"

Let's say that the output of the awk command is "bob". Once executed, afaik, the above causes the contents of expect_out(buffer) to be exactly:

Code:

awk 'NF == 10  && \$NF == strange_user_id {print \$(NF-2)}' file_with_my_info
bob
$

I can assign *all* of the buffer to a variable:

Code:

send "awk 'NF == 10  && \$NF == strange_user_id {print \$(NF-2)}' file_with_my_info\r"
 expect "\$ $"
set username $expect_out(buffer)

But all I want to assign to the variable is the last line before the prompt -- "bob". How do I do that? If it matters, I'm a little unclear about whether the prompt is actually in expect_out(buffer) or not. I might be asking how to save only the last line, or perhaps only the second-to-last. Please pardon my ignorance-- this really is my first attempt at an expect script, and the assignment of portions of output to a variable seems potentially useful.

---------- Post updated 02-04-10 at 11:24 AM ---------- Previous update was 02-03-10 at 07:11 PM ----------

(Moved thread to "Shell Programming..." from "...for Dummies")

---------- Post updated at 01:23 PM ---------- Previous update was at 11:24 AM ----------

Ah, ok... I think we have a winner. I learned about lindex and split, and so I added:

Code:

set resp1 $expect_out(buffer)
set resp2 [split $resp1 "\r"]
set servername [lindex $resp2 1]

That does the trick... now $servername can be called as needed later in the script. It's a little offensive to do it in two steps like that... I'll look into combining when I have time to brush up on TCL/Expect syntax.