C/Pointer/Pointer String

Reverse string content using its pointer

<source lang="cpp">

1. include <stdio.h>
2. include <string.h>

int main(void) {

 char str1[] = "Pointers are fun and hard to use";
 char str2[80], *p1, *p2;
 /* make p point to end of str1 */
 p1 = str1 + strlen(str1) - 1;
 p2 = str2;
 while(p1 >= str1)
   *p2++ = *p1--;
 /* null terminate str2 */
 *p2 = "\0";
 printf("%s %s", str1, str2);
 return 0;

}

      </source>

split an entry of the form Last/First into two parts

<source lang="cpp">

1. include <stdio.h>
2. include <string.h>
3. include <stdlib.h>

char *my_strchr(char *string_ptr, char find){

   while (*string_ptr != find) {
      if (*string_ptr == "\0")
          return (NULL);
      ++string_ptr;
   }
   return (string_ptr);

} int main() {

   char line[80]="asdf";
   char *first_ptr;
   char *last_ptr;
   line[strlen(line)] = "\0";
   last_ptr = line;
   first_ptr = my_strchr(line, "d");
   if (first_ptr == NULL) {
       fprintf(stderr,"Error: Unable to find "a" in %s\n", line);
   }
   return (0);

}

      </source>