#include <stdio.h>

int main()
{
	char str[10]="Hello";
	FILE *fp;
	char *p;

	if((fp=fopen("in.txt","w"))==NULL){
		printf("Error in opening file\n");
		return;
	}

	p=str;
	while(1){
		if(fputc(*p,fp)==EOF){
			printf("Error in writing file\n");
			break;
		}
		p++;
	}

	fclose(fp);

	if((fp=fopen("in,txt","r"))==NULL){
		printf("Error in reading file\n");
		return;
	}

	while(1){
		if (fgetc(fp)==EOF){
			printf("Error");
			break;
			putchar(fgetc(fp));
		}
	}
	fclose(fp);
}