66.文件映射为内存进行操作

#include<stdio.h>
#include<stdlib.h>
#include<Windows.h>

char path[256] = "kaifang.txt";

void main()
{
                              //路径，读写，    
    HANDLE hfile = CreateFileA(path, GENERIC_READ | GENERIC_WRITE, 0, NULL,
        OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);//打开一个文件

    //如果打开失败
    if (hfile ==INVALID_HANDLE_VALUE)
    {
        printf("打开文件失败");
        system("pause");
    }
    //获取文件大小
    printf("
%d", GetFileSize(hfile,NULL));
    //创建映射
    HANDLE hmap = CreateFileMappingA(hfile, 
        NULL, PAGE_READWRITE | SEC_COMMIT,//读写
        0, 
        GetFileSize(hfile, NULL) + 1,//文件大小多一位
        NULL);
    //判断是否映射失败
    if (hmap==NULL)
    {
        printf("映射失败");
        CloseHandle(hfile);
        system("pause");
    }
    //创建一个指针，存储映射以后的首地址
    PVOID pvfile = MapViewOfFile(hmap, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);

    if (pvfile==NULL)
    {
        printf("指针映射失败");
        CloseHandle(hfile);
        CloseHandle(hmap);
        system("pause");

    }

    puts("映射成功");
    char *pstart = pvfile;//首地址
    char *pend = pstart + GetFileSize(hfile, NULL);//结束地址
    system("pause");
    
    char str[100] = "test test";
    memcpy(pend, str, strlen(str));


    system("pause");
    UnmapViewOfFile(pvfile);//解除映射
    CloseHandle(hmap);
    system("pause");

}