You can use them to constrain input, apply formatting rules, and check lengths. This How To shows how you can use regular expressions within ASP. Objectives Overview Using a Regular Expression Validator Control Using the Regex Class Common Regular Expressions Additional Resources If you make unfounded assumptions about the type, length, format, or range of input, your application is unlikely to be robust.To validate input captured with server controls, you can use the Regular Expression Validator control. Input validation can become a security issue if an attacker discovers that you have made unfounded assumptions.To validate other forms of input, such as query strings, cookies, and HTML control input, you can use the System. The attacker can then supply carefully crafted input that compromises your application by attempting SQL injection, cross-site scripting, and other injection attacks.To avoid such vulnerability, you should validate text fields (such as names, addresses, tax identification numbers, and so on) and use regular expressions to do the following: Regular expression support is available to ASP. If you capture input by using server controls, you can use the Regular Expression Validator control to validate that input.I am using Regular expression validator for validating URL (of validators) Here is the expression: http(s)? Also, next time, you might want to include the programming language or context, because regex processors vary greatly in feature support. :[-a-z0-9] \.)*[-a-z0-9] .*)/i What this matches: Anything that starts with https://, or They prevent those specific groups of characters from being assigned a number.
It is provided as a courtesy for individuals who are still using these technologies.
How can I check if a given string is a valid URL address? Surely a good start: msdn.microsoft.com/en-us/library/ff650303NB. The above page is retired, but the expressions in the table are essentially still valid for reference.
My knowledge of regular expressions is basic and doesn't allow me to choose from the hundreds of regular expressions I've already seen on the web. The URL expression recommended (and which worked great for me) is: "^(ht|f)tp(s?
I agree that validation isn't easy, but urlparse does zero validation.
" | ":" | "@" | "&" | "=" hex = digit | "A" | "B" | "C" | "D" | "E" | "F" | "a" | "b" | "c" | "d" | "e" | "f" escape = "%" hex hex unreserved = alpha | digit | safe | extra uchar = unreserved | escape xchar = unreserved | reserved | escape digits = 1*digit i inserted this code for https and it works for me, |(?