Shell scripting: Matching and substituing between two lists

Micro420 · 05-20-2007, 02:29 AM

I want List B to search against List A. If List B's ip addresses match List A's ip addresses, then add/replace List A with the user's name.

For example:
(note that IP addresses purposely OUT OF ORDER)

List A:
192.168.0.1
192.168.0.3
192.168.0.2

List B:
192.168.0.1, joe@123.com
192.168.0.2, mary@456.com
192.168.0.3, paul@789.com

I would want List A to now look like:
192.168.0.1, joe@123.com
192.168.0.3, paul@789.com
192.168.0.2, mary@456.com

Is there a way for List B to partially compare against List A in a script, and if it has a match, replace it? The only thing I could think of would be using sed, but I don't know how to automate this. sed s/192.168.0.1/192.168.0.1, joe@123.com/g etc...

Assume I have this list with over 1,000 entries in them so doing this manually one-by-one is not an option.

ghostdog74 · 05-20-2007, 02:47 AM

Code:

awk -F", " ' NR == FNR { arr[$1]=$2;next; } {  print $1","arr[$1] } ' file2 file1

output:

Code:

# ./test.sh
192.168.0.1,joe@123.com
192.168.0.3,paul@789.com
192.168.0.2,mary@456.com

jschiwal · 05-20-2007, 04:58 AM

grep -f listA listB

This won't give an output if the IP address isn't in listB however.

Code:

grep -f listA listB
192.168.0.1, joe@123.com
192.168.0.2, mary@456.com
192.168.0.3, paul@789.com