linux 编程--目录相关

一.头文件

#include <dirent.h>

二.结构体

struct dirent
  {
#ifndef __USE_FILE_OFFSET64
    __ino_t d_ino;
    __off_t d_off;
#else
    __ino64_t d_ino;
    __off64_t d_off;
#endif
    unsigned short int d_reclen;
    unsigned char d_type;
    char d_name[256];		/* We must not include limits.h! */
  };

struct __dirstream
{
void *__fd; /* `struct hurd_fd' pointer for descriptor.   */
char *__data; /* Directory block.   */
int __entry_data; /* Entry number `__data' corresponds to.   */
char *__ptr; /* Current pointer into the block.   */
int __entry_ptr; /* Entry number `__ptr' corresponds to.   */
size_t __allocation; /* Space allocated for the block.   */
size_t __size; /* Total valid data in the block.   */
__libc_lock_define (, __lock) /* Mutex lock for this structure.   */
};
typedef struct __dirstream DIR;

三.API函数

int closedir(DIR *dirp);

关闭目录
DIR *opendir(const char *dirname);

打开目录
struct dirent *readdir(DIR *dirp);

读目录
void seekdir(DIR *dirp, long loc);

设置目录流目前的读取位置
long telldir(DIR *dirp);

目录流的当前位置

 

四.例子

#include	<sys/types.h>
#include	<dirent.h>
#include	<stdio.h>

int main(int argc, char *argv[])
{
	DIR	*dp;
	struct dirent	*dirp;

	if (argc != 2){
		printf("use like ./ls /dev \n");
		return 0;
	}

	if ((dp = opendir(argv[1])) == NULL){
		printf("can not open dir\n");
		return 0;
	}

	while ((dirp = readdir(dp)) != NULL)
		printf("%s\n", dirp->d_name);

	closedir(dp);
	return 0;
}