Regex on picking S3 bucket name from S3 URI

Question

I have been trying to regex pattern to obtain S3 bucket name from S3 URI but have no luck.

example: s3://example-bucket/file-name.filetype

Closest I could get with this: \\/\\/([^\\/].*[^\\/])\\/ but i'm not sure how to negate the slash from the result

Answer 1

The part ([^/]+) is looking for a sequence of of characters that are not slash. keeping close with what you had you could write //([^/]+)/ but this is the same as

//([^/]+)

optional you could use lookbehind (?<=//) and/or lookahead (?=/)

(?<=//)([^/]+)(?=/)

(depending on your use cases a couple of different lookahead expressions are possible)

'lookaround' especially 'lookbehind' is not supported in all regexp dialects. eg not in JavaScript

Debuggex Demo

Answer 2

If you don't have the lookbehind option (javascript regex), and your URL structure is consistent enough, then perhaps this pattern will be useful:

[^\\/]+(?=\\/[^\\/])

In English: "match one or more non-forward slashes, followed (but not actually matched, via the lookahead) by one forward slash and a non-forward slash".

(your other option would be to access your match groups in order to get rid of the slashes that you matched)

https://regex101.com/r/XM05Sw/2/