resolv.conf

Shell Programming and Scripting
1

HI ALL

I am making a script,That will does the following,I am in search of ideas

1.Script will comment all existing the entries in resolve.conf
2.Add new entries like this

 abc.example.com
  192.168.1.x

I can use sed to add comment.

2

How do you make sure another process (such as the DHCP client) does not try to modify the script while you're writing it?

Wouldn't it make better sense to write a new file all-at-once?

3

NO dchp is not running that's my server,i have many server so i need to make a script which run and check each reslove.conf and put specfic dns enties in each server reslove.conf.the value i gave you are fectious.

4

HI Again

I have made the script,In its initial stage,Need to ask one question i am taking backup of reslov.conf with this name reslov.conf~ but a problem is that when next time script run it will over write the backup file with new value.see my code you will get what i m saying ,Please ans this ASAP,its urgent.THX TO ALL


#!/bin/bash


sudo sed -i~ 's?^?#?' /home/syed/shellscript/resolv.conf


echo     search.example.com  >> resolv.conf

echo    nameserver xxx.xxx.x.x  >> resolv.conf

echo     nameserver xxx.xxx.x.x  >> resolv.conf

cat /home/syed/shellscript/resolv.conf
5

I think you are going about it the wrong way.

RESOLV=/home/syed/shellscript/resolv.conf
exec <$RESOLV >$RESOLV.new

while read line ; do 
   echo "# $line"
done

echo search.example.com
echo nameserver xxx.xxx.xxxx.xxxx
echo nameserver yyy.yyy.yyyy.yyyy

exec >-
mv $RESOLV $RESOLV.$$.bak 
mv $RESOLV.new $RESOLV
6

above line should be -> exec <$RESOLV >$RESOLV.new

Thanks,
bash

7

Not working see below


#! /bin/bash
RESOLV=/tmp/reslov.conf
exec < $RESOLV >$RESOLV.new

while read line ; do 
   echo "# $line"
done

echo search.example.com
echo nameserver xxx.xxx.xxxx.xxxx
echo nameserver yyy.yyy.yyyy.yyyy

exec >-
mv $RESOLV $RESOLV.$$.bak 
mv $RESOLV.new $RESOLV

tmp]$ ./resolv.sh2
./resolv.sh2: line 3: /tmp/reslov.conf: No such file or directory
^C

8

You are blind, waste alot time on small matter.

Thanks,
bash

9

You have to have the original resolv.conf in place first.