REGEX: To extract particular string from path

I am looking to extract particular string from path.

For example, I have to extract 4th value separated by (.) from filename. which is "lm" in below examples.

Examples:

/apps/java/logs/abc.defgh.ijk.lm.nopqrst.uvw.xyz.log
/apps2/java/logs/abc.defgh.ijk.lm.log

This will extract full file name:

.*\/(?<name>.*).log

You can use

.*\/(?:[^.\/]*\.){3}(?<value>[^.\/]*)[^\/]*$

Or, if .log must be the extension:

.*\/(?:[^.\/]*\.){3}(?<value>[^.\/]*)[^\/]*\.log$

See the regex demo. Details:

• .* - any zero or more chars other than line break chars, as many as possible
• \/ - a / char
• (?:[^.\/]*\.){3} - three occurrences of zero or more chars other than . and / as many as possible and a dot
• (?<value>[^.\/]*) - Group "value": zero or more chars other than . and / as many as possible
• [^\/]* - zero or more chars other than /
• \.log - a .log substring
• $ - end of string.