一切数据都是字节流

一切文件、数据都是以字节为单位进行读写。

#include <stdio.h>#include <stdlib.h>int main() {  int a = 1234;  int b = 5;  unsigned char *tmp = NULL;  int ret = 0;  FILE *fd = fopen("C:\\MinGW\\bin\\test.txt","w+");  printf("size of int is %d\n",sizeof(int));  if(!fd) {    printf("open file failed!\n");  }  if(!(ret=fwrite(&a,4,1,fd))) {    printf("failed fwrite,ret is %d\n",ret);  }  printf("write ret is %d\n",ret);  fclose(fd);  fd = fopen("C:\\MinGW\\bin\\test.txt","r");  fread(&b,4,1,fd);  tmp = (unsigned char*)&b;  printf("now tmp[0] is %d\n",tmp[0]);  printf("now tmp[1] is %d\n",tmp[1]);  printf("now tmp[2] is %d\n",tmp[2]);  printf("now tmp[3] is %d\n",tmp[3]);  fclose(fd);  system("pause");  return 0;}

其中核心测试数据1234,210,4对应的二进制数据分别如下：

1234 ->10011010010 210 ->   11010010   4 ->        100