Question

How can i check that a user has input a url into the terminal for my application? Is there some sort of regex i can use?

I am getting the input from the terminal in Linux and storing it in a char str[100] variable.

EDIT*
I need to check that they can only enter a URL that actually exists, if that is possible.

Answer 1

I use this regular expression. It does not allow for the ?…. at the end though.

^https?://(((0|([1-9][0-9]{0,1}))(\.(0|([1-9][0-9]{0,1}))){3})|([a-zA-Z]([a-zA-Z0-9$\-_@\.&+*"\'\(\),]|(%[0-9a-fA-F][0-9a-fA-F]))*(\.([a-zA-Z]([a-zA-Z0-9$\-_@\.&+!*"\'\(\),]|(%[0-9a-fA-F][0-9a-fA-F]))*))*))(/|((/([a-zA-Z]([a-zA-Z0-9$\-_@\.&+!*"\'\(\),]|(%[0-9a-fA-F][0-9a-fA-F]))*))*))$

PS: I constructed it from an RFC