仿写头文件 dirent.h
模拟linux下头文件 myDirent.h
#ifndef MYDIRENT_H
#define MYDIRENT_H
typedef struct _dirdesc {
int dd_fd; /** file descriptor associated with directory */
long dd_loc; /** offset in current buffer */
long dd_size; /** amount of data returned by getdirentries */
char *dd_buf; /** data buffer */
int dd_len; /** size of data buffer */
long dd_seek; /** magic cookie returned by getdirentries */
} DIR;
# define __dirfd(dp) ((dp)->dd_fd)
DIR *opendir(const char *);
struct dirent *readdir(DIR *);
void rewinddir(DIR *);
int closedir(DIR *);
#include <sys/types.h>
struct dirent
{
long d_ino; /* inode number*/
off_t d_off; /* offset to this dirent*/
unsigned short d_reclen; /* length of this d_name*/
unsigned char d_type; /* the type of d_name*/
char d_name[1]; /* file name (null-terminated)*/
};
#endif
实现函数 cpp
windows下仿写opendir() readdir() closedir()
利用FindFirstFile() FindNextFile() 这两个windows函数
myDirent.cpp
#include <iostream>
#include <string>
#include <stdio.h>
#include <windows.h>
#include "myDirent.h"
static HANDLE hFind;
DIR *opendir(const char *name)
{
DIR *dir;
WIN32_FIND_DATA FindData;
char namebuf[512];
//int sprintf ( char * str, const char * format, ... ); Write formatted data to string
sprintf(namebuf, "%s\\*.*", name);
hFind = FindFirstFile(namebuf, &FindData);
if (hFind == INVALID_HANDLE_VALUE)
{
printf("FindFirstFile failed (%d)\n", GetLastError());
return 0;
}
dir = (DIR *)malloc(sizeof(DIR));
if (!dir)
{
printf("DIR memory allocate fail\n");
return 0;
}
memset(dir, 0, sizeof(DIR));
dir->dd_fd = 0; // simulate return
return dir;
}
struct dirent *readdir(DIR *d)
{
int i;
BOOL bf;
WIN32_FIND_DATA FileData;
if (!d)
{
return 0;
}
bf = FindNextFile(hFind, &FileData);
//fail or end
if (!bf)
{
return 0;
}
struct dirent *dir = (struct dirent *)malloc(sizeof(struct dirent) + sizeof(FileData.cFileName));
for (i = 0; i < 256; i++)
{
dir->d_name[i] = FileData.cFileName[i];
if (FileData.cFileName[i] == '\0') break;
}
dir->d_reclen = i;
dir->d_reclen = FileData.nFileSizeLow;
//check there is file or directory
if (FileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
dir->d_type = 2;
}
else
{
dir->d_type = 1;
}
return dir;
}
int closedir(DIR *d)
{
if (!d)
return -1;
hFind = 0;
free(d);
return 0;
}
测试一下
int main()
{
// use as readdir() in Linux
DIR *dir;
struct dirent *ptr;
char *flow[65536];
int num = 0, i = 0;
if ((dir = opendir("E:\\data_of_weibo\\data_washed\\event_max_time")) == NULL) {
std::cerr << "open dir error." << std::endl;
return false;
}
while ((ptr = readdir(dir)) != NULL) {
flow[num] = (char *)malloc(sizeof(char));
strcpy(flow[num], ptr->d_name); //char d_name[1];
num++;
}
// output test
for (i = 0; i < num; ++i) {
if (strcmp(flow[i], "..") == 0 || strcmp(flow[i], ".") == 0)
std::cout << "find last directory." << std::endl;
else
std::cout << std::string(flow[i]) << std::endl;
}
std::cout << "total file: " << num - 1 << std::endl;
closedir(dir);
std::cout << "Press any key to continue.." << std::endl;
getchar();
return 0;
}
update:
//上面的写法,strcpy拷贝之后free flow数组会出问题,可能是覆盖了维护数据结构,改一下
int main()
{
// use as readdir() in Linux
DIR *dir;
struct dirent *ptr;
std::vector<std::string> resVec;
int num = 0, i = 0;
if ((dir = opendir("E:\\data_of_weibo\\data_washed\\event_max_time")) == NULL) {
std::cerr << "open dir error." << std::endl;
return false;
}
while ((ptr = readdir(dir)) != NULL)
resVec.push_back(std::string(ptr->d_name)); //char d_name[1];
for (unsigned j = 0; j < resVec.size(); j++)
std::cout << resVec.at(j) << std::endl; //包含 ".." 上级目录
std::cout << resVec.size() << std::endl;
closedir(dir);
std::cout << "Press any key to continue.." << std::endl;
getchar();
return 0;
}
结果
注意结果里面有 “..” 上级目录,顺序是按照字母表顺序读取
今天的文章windows下类似linux readdir()读取文件分享到此就结束了,感谢您的阅读。
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