REGEX: To extract particular string from path

Question

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

score 1 · Accepted Answer · answered Sep 06 '21 at 10:20

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.

score 0 · Answer 2 · answered Sep 06 '21 at 10:32

You can also try

\/(?:\w+\.){3}(\w+)

Or

\/(?:\w+\.){3}(\w+).*\.log

Where:

\/ - Match string starting from "/"
(?:\w+\.){3} - Matches 3 occurrences of "xyz." e.g. abc.defgh.ijk.
(\w+) - Capture the alpanumeric string. This will contain the target value e.g. "lm"
.*\.log - Optional. Match any set of characters that ends with .log e.g. .nopqrst.uvw.xyz.log

2 Answers2