Regular Expressions 101

Positive Lookbehind(?<=username-)

username-the literal text username- (case sensitive)

Group 1(\w+\.\w+)

\w+any word character, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\w+any word character, repeated at least once

.*?any character (except for line terminators), repeated any number of times

IP-the literal text IP- (case sensitive)

Group 2((\d{1,3}\.){3}(\d{1,3}))

Group 3(\d{1,3}\.){3}

{3}repeats the group contents below exactly 3 times:

\d{1,3}a digit, repeated between 1 and 3 times

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 4(\d{1,3})

\d{1,3}a digit, repeated between 1 and 3 times

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?<=username-)(\w+\.\w+).*?IP-((\d{1,3}\.){3}(\d{1,3}))

New

03-25-2022  18:02:51    Local1.Notice   192.168.1.1 Mar 25 18:02:51 2022 192.168.1.1 stm[6358]: <501199> <NOTI> AP:AP01 <192.168.1.1 aa:bb:cc:dd:ee>  User authenticated, mac-aa:bb:cc:dd:ee, username-my.username, IP-192.168.250.100, method-802.1x, role-blahblah

Regular Expression

Extraction