sed, line range, inclusive/exclusive

[Jim Easton]

Dear People,

I don't think I could properly call this a bug - more like a
simple question.  I have been using sed for 20 years and have
never figured out how to do the following:

How does one select a group of lines the first of which has a
unique pattern and the following lines another pattern.

Or to rephrash this the info/man pages say that one can select
a range of lines with two addresses the second of which is
*inclusive*.  How can I make the second address *exclusive*?
ie. *not* included in the range.

This came up for the umpteenth time when I was trying to sift
email messages which contain, among a lot of other stuff, several
sets of lines begining with "Received:" and followed by lines
begining with a "tab"  I would like to delete (or select them
for some sort of substitution) that group of lines without
necessarily deleting the following non-tab line.  It might or
might not be be another "Received:" line which one would like
to select or not.

I have tried many things none of which worked.  Including the
"c" command, which incidently didn't allow for a null text.
Following is a some test data, just one of many desperation
scripts and the output.

Please tell me how an expert would accomplish this.  I could do
it in shell, C or my knowledge of perl (God forbid) is sketchy
at best but I wanted to use sed.

        Jim

Following is a simplified test message:

>From address@hidden  Mon Mar  8 21:28:35 2004
Received: line 0 0
        line 0 1
        line 0 2
        line 0 2
Received: line 1 0
        line 1 1
        line 1 2
        line 1 3
Received: line 2 0
        line 2 1
        line 2 2
        line 2 3
        line 2 4
Received: line 3 0
        line 3 1
        line 3 2
        line 3 3
        line 3 4
Date:   Mon, 08 Mar 2004 20:22:05 -0800
From:   address@hidden
Subject: this is a test

This is the body of the message



#!/bin/sh
# attempt to delete "Received:" groups.

cat m1 | 
sed '
        /^Received:[    ]/,/^[^         ]/ {
                s/^\(Received:\)/\1 DALETE/
                s/^     /        DELLTE /
                }
        /^Received:[    ]/,/^[^         ]/ {
                s/^\(Received:\)/\1 DALL /
                s/^     /        DELL/
                }
         ' 

Produced the following output from the above test data.

>From address@hidden  Mon Mar  8 21:28:35 2004
Received: DALL  DALETE line 0 0
         DELL DELLTE line 0 1
         DELL DELLTE line 0 2
         DELL DELLTE line 0 2
Received: DALL  DALETE line 1 0
        line 1 1
        line 1 2
        line 1 3
Received: DALL  DALETE line 2 0
         DELL DELLTE line 2 1
         DELL DELLTE line 2 2
         DELL DELLTE line 2 3
         DELL DELLTE line 2 4
Received: DALL  DALETE line 3 0
        line 3 1
        line 3 2
        line 3 3
        line 3 4
Date:   Mon, 08 Mar 2004 20:22:05 -0800
From:   address@hidden
Subject: this is a test

This is the body of the message