How to check if C string is empty

Question

I\'m writing a very small program in C that needs to check if a certain string is empty. For the sake of this question, I\'ve simplified my code:

#include 

        

Answer 1

It is very simple. check for string empty condition in while condition.

1. You can use strlen function to check for the string length.

   #include
   #include    
   
   int main()
   {
       char url[63] = {'\0'};
       do
       {
           printf("Enter a URL: ");
           scanf("%s", url);
           printf("%s", url);
       } while (strlen(url)<=0);
       return(0);
   }
   

2. check first character is '\0'

   #include     
   #include 
   
   int main()
   {        
       char url[63] = {'\0'};
   
       do
       {
           printf("Enter a URL: ");
           scanf("%s", url);
           printf("%s", url);
       } while (url[0]=='\0');
   
       return(0);
   }
   

For your reference:

C arrays:
https://www.javatpoint.com/c-array
https://scholarsoul.com/arrays-in-c/

C strings:
https://www.programiz.com/c-programming/c-strings
https://scholarsoul.com/string-in-c/
https://en.wikipedia.org/wiki/C_string_handling