Demo Spanning Strings, Strspn() and Strcspn()

#include <stdio.h>
#include <string.h>
#include <stdio.h>

/* 
size_t strspn ( char *stting, char *set_to_skip_over) ;
size_t strcspn( char *string, char *set_to_find_in)

Q are there chars in char set *set_to_find, 
   return #chars skipped until char found  

Q are there chars in char set *set_to_skip_over, 
   return #chars skipped until char found  
*/
int main(void) {
    char sentence[] = "Hello. I am John!" ;
    char nonsense[] = "~*%#" ;
    char letters[]  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
                       abcdefghijklmnopqrstuvwxyz" ;
    int numskipped;
    
    numskipped = strcspn (sentence, letters) ;
    printf ("%d chars skipped over until a letter was found.\n",
        numskipped) ;
    numskipped = strspn (sentence, letters) ;
    printf ("%d chars skipped over until a non-letter was found.\n",
        numskipped) ;    
    numskipped = strcspn (sentence, nonsense) ;
    printf ("%d chars skipped over until a nonsense character was found.\n",
        numskipped) ;
    
    return 0;
}