c语言2进制文件操作

//最为稳妥不出错的方法……（这话说的）

//要点，正真读写操作时以rb+后缀最为稳妥，不带b时fseek函数的走位比较醉。w会覆盖。a不让走位……

#include"闫文山.h"
int main(){
FILE *fp;
int a = 2147483644;
int b = 4;
char d = 'n';
char c[4] = "四";
if ((fp = fopen("d:\\text.bin", "r")) == NULL){
printf("不存在该文件，是否新建？'y' or no");
if((d = getchar()) != 'y'){
return 1;
}
else{
fflush(stdin);
fp = fopen("d:\\text.bin", "w");
}
}
fclose(fp);
if ((fp = fopen("d:\\text.bin", "rb+")) == NULL){
printf("二次文件打开异常");
exit(0);
}
fseek(fp,0,2);
fwrite(c, sizeof(c), 1, fp);

fclose(fp);
return 0;
}