K&R(5.3): Pointers and Arrays

/* k&r(5.3): Pointers and Arrays
   created on Mar 21, 2011
*/
#include    "stdio.h"

int strlen(char *);
/* main: computes the length of a string */
int main()
{
    char str[] = "hello mark";
    int length;
    length = strlen(str);
    printf("the length is %d\n", length);
    return 0;
}

/* strlen: return length of string s*/
int strlen(char *s)
{
    int n;
    for (n = 0; *s != '\0'; s++)
      n++;
    return n;
}