Regular Expressions 101

Client logging in as the literal text Client logging in as (case sensitive)

Group user_login(?<user_login>[^ ]*)

Negated Character Class[^ ]*

*matches any number of characters outside the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

Negative Lookahead(?!.*failed)

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

failedthe literal text failed (case sensitive)

Global pattern flags

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

Client logging in as (?<user_login>[^ ]*)(?!.*failed)

New

 2017/09/26 09:44:05 Client logging in as robertE on DB1...
 2017/09/26 09:45:54 Client logging in as  on DB1... ERROR:Missing login information
 2017/09/26 08:58:02 Client logging in as jamesH on DB1... Connect to Oracle failed: 
 ORA-01017: invalid username/password; logon denied