在上文介绍了C中文件操作的一些基本函数，下面给一个简单例子，完成从控制台输入一段字符串，然后将其写入文件，然后从文件中读出刚刚写入的内容，代码如下：

#include <stdio.h>#include <string.h>#include <stdlib.h>const int LENGTH=80;int main(void){	char mystr[LENGTH];	int lstr=0;	int mychar=0;	FILE * pfile=NULL;	char *filename="C:\\temp\\test.txt";	printf("\nEnter an interesting string of less than 80 characters:\n");	fgets(mystr,LENGTH,stdin);	if(!(pfile=fopen(filename,"w")))	{		printf("Fail to open");		exit(1);	}	lstr=strlen(mystr);	for(int i=0;i<lstr;i++){		fputc(mystr[i],pfile);	}	fclose(pfile);		if(!(pfile=fopen(filename,"r")))	{		printf("Fail to open");		exit(1);	}	printf("This is the content of your interesting string:\n");	while((mychar=fgetc(pfile))!=EOF)		putchar(mychar);	putchar('\n');	fclose(pfile);	//	remove(filename);	return 0;}