How to search and replace

[Paul Howarth]

Dan Track wrote:
> Hi
> 
> I thought I'd ask this here as you guys helped me setup mrtg :)
> 
> I've got the following pattern in a text file in linux.
> Target[description1].1.3.4.6.5.3.:string at 10.11.8.10
> Directory[description1]: server1
> 
> Target[description2].1.3.4.6.4.9.:string at 10.17.5.24
> Directory[description2]: server2
> 
> What I would like to do is replace the ip of each with the following
> value of "Directory". So for example I would like
> Target[description1].1.3.4.6.5.3.:string at 10.11.8.10 to become
> Target[description1].1.3.4.6.5.3.:string at server1.example.com
> 
> How can I accomplish this using either C,perl,sed or awk

sed -e '$b
   /^Target\[[^]]*\][.0-9]*:.*@[0-9.]*$/ {
     $!N
     s/^\(Target\[[^]]*\][.0-9]*:.*@\)[0-9.]*\nDirectory\[[^]]*\]: 
\(.*\)$/\1\2.example.com/
     P;D
   }' textfile > output

Paul.