#include <stdio.h>   /* C example */
#include <stdlib.h>
#include <errno.h>   /* for errno */
#include <string.h>  /* for strerror */

int main(int argc, char **argv)
{
	FILE *fp;
	long position;
	char buffer[256];

	fp = fopen("file", "w+");
	if (fp == NULL) {
		fprintf(stderr, "can't open file: %s\n", strerror(errno));
		return EXIT_FAILURE;
	}

	fprintf(fp, "hello\n");
	if (fflush(fp) != 0) {
		fprintf(stderr, "can't fflush: %s\n", strerror(errno));
		return EXIT_FAILURE;
	}

	position = ftell(fp);
	if (position == -1) {
		fprintf(stderr, "can't ftell: %s.\n", strerror(errno));
		return EXIT_FAILURE;
	}
	printf("position %ld\n", position);

	if (fseek(fp, 0, SEEK_SET) != 0) {   /* rewind file back to beginning */
		fprintf(stderr, "can't fseek: %s.\n", strerror(errno));
		return EXIT_FAILURE;
	}

	position = ftell(fp);
	if (position == -1) {
		fprintf(stderr, "can't ftell: %s.\n", strerror(errno));
		return EXIT_FAILURE;
	}
	printf("position %ld\n", position);

	if (fscanf(fp, "%s", buffer) != 1) {
		fprintf(stderr, "can't fscanf\n");
		if (ferror(fp)) {
			fprintf(stderr, ": %s", strerror(errno));
		}
		fprintf(stderr, ".\n");
	}

	printf("%s\n", buffer);

	if (fclose(fp) != 0) {
		fprintf(stderr, "can't fclose: %s.\n", strerror(errno));
		return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;
}