Validating a url path with regex and excluding special characters-CodePudding

I'm trying to write up an expression that starts with a '#" and takes in the following types of paths and only takes in a character A-z/a-z and doesn't accept digits or special characters: Example valid paths:

#/
#/word/word
#/word
#/word/word/word

This is what I have currently:

#\/\D |\/\D

I have also tried:

#\/\D |\s\/^[A-Za-z\s]*$

It filters 85% of the paths correctly but it still accepts paths with special characters as valid such as "#/word/word?test=word" "#/word/word=%"

I'm not quite sure what I am missing.

CodePudding user response：

I would phrase the regex as:

^(?:#/|#/[A-Za-z] (?:/[A-Za-z] )*)$

This regex says to match:

^ from the start of the string
(?:
- #/ match #/ by itself
- | OR
- #/ match #/
- [A-Za-z] followed by a path name
- (?:/[A-Za-z] )* followed by zero or more other paths
)
$ end of the string

Demo

CodePudding user response：

You can start the match with #/ and then optionally match the trailing part:

^#\/(?:[A-Za-z] (?:\/[A-Za-z] )*)?$

Explanation

^ Start of string
#\/ Match #/
(?: Non capture group
- [A-Za-z] Match 1 chars A-Za-z
- (?:\/[A-Za-z] )* Optionally repeat / and 1 chars A-Za-z
)? Close the non capture group and make it optional
$ End of string

See a regex demo.