NUL undeclared- first use in this function

Question

From the web I understand that C contains NUL keyword.

But while compiling I get an error

NUL undeclared first use in this function\'
         


        

Answer 1

No, that's not standard. Add this at the beginning of your code or just use 0:

#define NUL 0

I infered you're not looking for NULL since you're doing ch == NUL

In various texts it is quite frequent to refer to '\0' as NUL.