From rouben@sun2.math.umbc.edu Mon Apr 20 20:45:33 1998
Path: fu-berlin.de!feeder.qis.net!news.umbc.edu!not-for-mail
From: rouben@sun2.math.umbc.edu (Rouben Rostamian)
Newsgroups:
  alt.unix.wizards,comp.unix.aix,comp.unix.admin,comp.unix.misc,comp.editors
Subject: Re: Can sed do this??
Followup-To: comp.editors
Date: 11 Apr 1998 13:09:28 -0400
Organization: University of Maryland Baltimore County
Lines: 49
Distribution: inet
Message-ID: <6go848$4jd@sun2.math.umbc.edu>
References: <352EFB3C.A5B95A41@nettally.com>
NNTP-Posting-Host: sun2.math.umbc.edu
Xref: fu-berlin.de alt.unix.wizards:13014 comp.unix.aix:133213
  comp.unix.admin:79040 comp.unix.misc:39056 comp.editors:30780

In article <352EFB3C.A5B95A41@nettally.com>,
Bob Tortajada  <bobt@nettally.com> wrote:
>I need to edit a file from a shell script and don't know how to do one
>thing. Specifically, the file I need to edit is /etc/filesystems so here
>is an example
>
>/mnt/fs1:
>            dev           = /dev/lv1
>            vfs            = jfs
>            log            = /dev/log1
>
>/mnt/fs2:
>            dev           = /dev/lv2old
>            vfs            = jfs
>            log            = /dev/log1
>In the above example, we only want to change the entry's with old in
>their name, but what we want to change it the log entry two lines down.
>What I want to do is basically search for old then search for log and
>change log1 to log2. As far as I can see, sed doesn't work that way. Is
>this possible with sed?

(Note that I have changed the Followup-To: line)

Make a file, say script.sed, with the following contents:

-------------------------------
:b1
/old/{
        :b2
        n
        /log/{
                s/log1/log2/
                n
                bb1
        }
        bb2
}
-------------------------------


Then do:

sed -f script.sed infile > outfile

You may want to strengthen the regexps /old/ and /log/ to make
the script fool-proof.

-- 
Rouben Rostamian <rostamian@umbc.edu>