Demonstrates the use of strchr(), written for a tutorial.

gistfile1.h

/* 
 * Demonstrates the use of strchr to count the number of spaces in a string
 * entered by the user. 
 * 
 * Prepared for tutorial purposes by David Warde-Farley, CSC209H Winter 2008
 */

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

#define BUFSIZE 100

int
main()
{
	char buf[BUFSIZE];

	int numspaces = 0;  /* To keep track of the number of spaces.     */

	char *ptr;          /* A pointer to move through the string with. */

	printf("Enter a string: ");
	fgets(buf, BUFSIZE, stdin);

	/* Ask strchr to find the first space */	
	ptr = strchr(buf, ' ');

	/* 
	 * strchr will return NULL when it gets to the end of the string
	 * and finds no more spaces.
	 */
	while (ptr != NULL) 
	{
		numspaces++;

		printf("Returned by strchr: %s", ptr);
		/* 
		 * Get us past the space we just found by incrementing 
		 * our pointer by one; without this we loop forever.
		 */
		ptr++;
		
		/* Let strchr find the next space. */
		ptr = strchr(ptr, ' ');
	} 

	printf("\nFound %d spaces in your string.\n", numspaces);
	return 0;
}