comparison of files

[Scott W]

Brent Bailey wrote:

>hello,
>
>I have been trying to write a shell script that will compare 2 files and
>generate a 3rd.
>
>i have a list of abusive IP's generated by our router. I want to compare
>it against a list of known abuse IPs ..and have it create a file of repeat
>offenders.
>
>ive tired to use "comm" to compare file1 against file2 doing something like
>
>comm -12i file1 file2 >file3
>
>however it doesnt seem to work....any suggestions ?
>
>thank you for all your help in advance
>  
>
You need to sort the files first...see below for difference in comm 
behavior...

Script started on Tue Dec 16 20:27:59 2003
freeb# cat blacklist1
192.168.1.2
192.168.1.1
192.168.1.10
freeb# cat blacklist2
192.168.1.1
192.168.1.10
freeb# comm -i12 blacklist1 blacklist2
freeb# sort blacklist1 > blacklist1_sorted
freeb# sort blacklist2 > blacklist2_sorted
freeb# comm -i12 blacklist1_sorted blacklist2_sorted
192.168.1.1
192.168.1.10

Script done on Tue Dec 16 20:29:14 2003


Scott