This regexp can be used to validate domain names in Golang. While it cannot enforce the 253 character limit (with optional trailing period not included) that can be easily done by a simple len(domain) <= 253 check as well. This can be used as-is in other languages, even with RE2 regex engine. If po...

Four examples of word wrapping at the 80 character mark, each one taking fewer steps than the last. Comment and uncomment lines with # to see the difference between versions. Optimization discussions welcome!

This regex can capture any column name from a select query. Be the original name, like are named on table, renamed with a reserved word AS or even without explicit AS. Go on, and test with your query ;)

Validates that you provide a CIDR in one of the following valid ranges. 0.0.0 – 127.255.255.255 127.0.0.0/8 0.0.0 – 10.255.255.255 10.0.0.0/8 16.0.0 – 172. 31.255.255 172.16.0.0/12 192.168.0.0 – 192.168.255.255 192.168.0.0/16...

Notes: Do not forget to escape the $ by an additional $. Escaping ? like \? does not work. But you could use [?] instead End result should be like this: "traefik.http.middlewares.r6tt-dev-web.stripprefixregex.regex=^/[a-z0-9/]+[a-z0-9]+([?]+.*)?$$"...

Find all string matches with dir, one or more subdir, file name with optional extension. Common example with all capturing groups included: C://ProgramFiles/MyDir1/myDir2/file.ext

Find all string matches with dir, one or more subdir, file name with optional extension. Common example with all capturing groups included: ../../dir/SubDir1/SubDir2/file.ext ...

The is helpful for parsing the symbolic reference of a PHP class object for validation or just determining the type and target for the operator. The expression is intended for working with classes and class methods, so the value on the right of the Paamayim Nekudotayim :: will alway be regarded as ...

for quadratic equations ||ax^2+bx+c=d||

验证阿拉伯数字金额 "-999999999 ~ 999999999" ,小数点后面保留2位