/*

* srch_str.c

* This program reads two strings and finds all the occurrences of the second

* string within the first.

*/

#include <stdio.h>

#include <string.h>

#define MAX_LENGTH 80

int main ()

{

char str1[MAX_LENGTH + 1]; /* The first string. */

char str2[MAX_LENGTH + 1]; /* The second string. */

char *p_suffix; /* The current suffix of the first string. */

char *p_place; /* The current occurence of the second string

in this suffix. */

int index; /* The index in which it occurs. */

int n_occurs = 0; /* Total number of occurences. */

/* Read the input strings. */

printf ("1. Please enter a string (at most %d characters): ", MAX_LENGTH);

scanf ("%s", str1);

printf ("2. Please enter a string (at most %d characters): ", MAX_LENGTH);

scanf ("%s", str2);

/* Initially, the suffix of str1 equals the entire string. */

p_suffix = str1;

while ((p_place = strstr (p_suffix, str2)) != NULL)

{

/* Print the current occurence. */

index = p_place - str1;

printf ("- Found \"%s\" at index %d.\n", str2, index);

/* Take the suffix so it begins one character after the location of the

current occurence of str2. */

p_suffix = p_place + 1;

/* Update the number of occurences. */

n_occurs++;

}

printf ("Found %d occurence%s in total.\n",

n_occurs, (n_occurs == 1) ? "" : "s");

return (0);

}