Question

I need some help from the shell-script gurus out there.

I have a .txt file (log) that traces the IP addresses of clients on several lines, in a format similar to this one:

Line1 - Client IP [192.168.0.1] Other data Line2 - Client IP [192.168.0.2] Other data Line3 - Client IP [192.168.0.3] Other data Line4 - Client IP [192.168.0.2] Other data Line5 - Client IP [192.168.0.1] Other data ... 

I need to create script that:

• extracts the IP addresses from this file
• groups the IP addresses (the same IP address is reported only once)
• outputs a file with the resulting IP addresses

For the previous example, the resulting file would be:

192.168.0.1 192.168.0.2 192.168.0.3 

I am on the Windows OS, but I can use tools like Cygwin or Unix Tools (that provide Unix-like commands as grep, sort, etc. under Windows).

A solution without scripting could be good as well.

Thanks in advance for your help.

Answer 1

In PowerShell:

The Verbose Way –

$regex = '(?<IPAddress>\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})' get-content log.txt | where-object {if ($_ -match $regex){$matches.ipaddress}} | group-object -noelement 

Shorter version

gc log.txt | % {if ($_ -match $regex){$matches.ipaddress}} | group -n