Question

How to extract the IP of the string below using RegEx?

... sid [1544764] srv [CFT256] remip [10.0.128.31] fwf []...

I tried the code below but did not return the expected value:

string pattern = @"remip\ \[.\]";
MatchCollection mc = Regex.Matches(stringToSearch, pattern );

Thanks in advance.

Answer 1

Try this:

@"remip \[(\d+\.\d+\.\d+\.\d+)\]"

To clarify… the reason yours doesn’t work is because you are only matching . inside the [ and ]. A single . matches only a single character. You could add a * (zero or more) or a + (one or more) to make it work. In addition, surrounding it with parenthesis: ( and ), means you can extract just the IP address directly from the second item in the MatchCollection.