1 //判断读到文件末尾 2 #include 
     
       3 #define F_PRINT_ERR(e)\ 4 do\ 5 {\ 6     if(e == NULL)\ 7     {\ 8       printf("open error");\ 9       exit(-1);\10     }\11 }\12 while(0)13 int main(int argc,char* argv[])14 {15 16     FILE* pf = fopen("G:/qtcode/pfw.txt","w+");17     F_PRINT_ERR(pf);18 //往文件里写几个字符进去19     char ch;20     for(ch = 'a';ch <= 'd';ch++)21     {22         putchar(fputc(ch,pf));23     }24     putchar(10);25     rewind(pf);26 //尝试通过两种方式判断读到文件末尾27 #if 028     //错误用法29     while(!feof(pf))//30     {31         ch = fgetc(pf);32         printf("%x->%c\n",ch,ch);33     }34 #endif35 36 #if 037     //正确用法，先读再判断38     while((ch = fgetc(pf)) && (!feof(pf)))39     {40         printf("%x->%c\n",ch,ch);41     }42 #endif43 44 #if 045     //正确用法，先读再判断46     ch = fgetc(pf);47     while(!feof(pf))48     {49         printf("%x->%c\n",ch,ch);50         ch = fgetc(pf);51     }52 #endif53 54 #if 155     while((ch = fgetc(pf)) != EOF)56     {57         printf("%x->%c\n",ch,ch);58     }59 #endif60 61     return 0;62 }