Shell Programming and Scripting

Hi Guru's

I have a hosts file which has around 1000 entries. I have been asked to change around 500 of the entries. The entries are in a file called hosts.new.
I tried using the diff command to get the uncommon one's. But the output was very confusing.
Would appreciate if you can help me out.

Thanks.

I'm personally a fan of sdiff

The output is pretty man-readable.

Thanks for the reply.
But what i ideally want is a list of host entries which are there in hosts file but not there in hosts.new file.
Is there any way command for that?

Have a look at the comm command.

Guru

Looked up comm command and infact got near to what i want.
But i presume,the two host file entries have to be in same sequence for correct results.

I tried the command "comm -12 hosts hosts.new" which displays all the common entries.
But if i change the host entries position in the file,this doesn't seem to work. Is it necessary that the entries need to be in some sequence?

Yes; as per the manual page, it expects sorted input.

To clarify, the hosts file doesn't need to be sorted, but the comm command works with 2 sorted files.
A limitation of the comm command is that it works with whole lines. Not much help if you have lines where a host NAME is in both files, but the address is different.
I don't think you can easily do this with shell script (definitely not efficiently, but that doesn't matter for 1-time use).
Have you considered using Perl instead.

Or better yet, have you considered using DNS instead of large hosts files?