/* Illustrate the differences between char * and an array of characters (string).
 */
#include <stdio.h>
#include <string.h>

int main() {
    char * s1 = NULL;
    char s2[20] = "abcdef";
    char s3[20] = "abcdef";
    int i;

    /* Why does this not work? */
    if ( s2 == s3 ) {
        printf("s2 = %s equals s3 = %s\n", s2, s3);
    } else {
        printf("s2 = %s does not equal s3 = %s\n", s2, s3);
    } /* if */

    /* Pointer arithmetic versus indexing. */
    s1 = s2;
    for ( i = 0; i < strlen(s2); i += 1 ) {
        printf( "s1 = %c, s2[%d] = %c\n", *s1, i, s2[i] );
        s1 += sizeof(char);
    } /* for */

    s1 = s2;
    printf("Now s1 = %s\n", s1);

    /* Generate a segmentation fault by over running the amount of space allocated for s1.
     */
    for (;;) {
        s1 = strcat(s1,s2);
        printf("%s", s1);
    } /* for */
} /* main */