topic Re: nslookup shell script with input and output files in Operating System - Linux

nslookup shell script with input and output files

jamesatwork — Wed, 07 Mar 2007 16:11:59 GMT

Hello! Please help!
I have a slight dilema, the data in my forward and reverse zones differ quite a bit. How would I write a shell script that would take an input file list of fqdn or ip and run nslookup on them and output a log file based on the results? I wrote one a while ago for batch but I am just learning unix/shell.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=960329

Is very close to what I need. Thanks in advance!

Re: nslookup shell script with input and output files

James R. Ferguson — Wed, 07 Mar 2007 16:20:13 GMT

Hi:

This could be as simple as:

# cat .mylookup.sh
while read ADDR
do
nslookup ${ADDR} | tee -a mylookup.log
done < mylookup

...where 'mylookup' is a file with one IP or FQDN per line:

10.10.11.12
host01.xyz.net
host02.xyz.net

...run as:

# ./mylookup.sh

...Your output will be written to your terminal and to the 'mylookup.log' file.

Regards!

...JRF...

Re: nslookup shell script with input and output files

jamesatwork — Wed, 07 Mar 2007 17:52:02 GMT

ok great! that works well, is it possible to make a tweek request, it should not be more than a quick if statement, I don't know how errors work in nix world yet but if name or ip is resolvable can the file have
- resolves
and if it doesn't
- does not resolve
Thanks so far, your help is very much appreciated!

Re: nslookup shell script with input and output files

James R. Ferguson — Wed, 07 Mar 2007 19:00:13 GMT

Hi (again):

OK, here's a simple hack:

# cat ./mylookup
#!/usr/bin/sh
while read ADDR
do
RESULT=`nslookup ${ADDR} | grep -E "^Address:"`
if [ ! -z "${RESULT}" ]; then
echo "${ADDR} is_ok" | tee -a mylookup.log
fi
done < mylookup

...run this just as you did the first version. Good results have a line in their output that begins with "Address:". The caret (^) anchors the pattern to match to the beginning of the line. Thus only lines that start with "Address:" are captured. If nothing matches, then 'nslookup' reports the target in the error returned, so we just print that.

Have a look at the manpages for 'nslookup'.

Regards!

...JRF...

Re: nslookup shell script with input and output files

jamesatwork — Wed, 07 Mar 2007 19:08:30 GMT

thank you!! that is the start I needed, cheers!