【APUE】目录操作

函数原型

opendir

	#include 
	#include 

	DIR *opendir(const char *name);
	DIR *fdopendir(int fd);

readdir

	#include 

	struct dirent *readdir(DIR *dirp);

struct dirent 结构体定义：

	struct dirent {
	   ino_t          d_ino;       /* Inode number */
	   off_t          d_off;       /* Not an offset; see below */
	   unsigned short d_reclen;    /* Length of this record */
	   unsigned char  d_type;      /* Type of file; not supported
									  by all filesystem types */
	   char           d_name[256]; /* Null-terminated filename */
	};

closedir

	#include 
	#include 

	int closedir(DIR *dirp);

示例

kls.c

#include "khead.h"
#include 
#include 

int main(int argc, char* argv[]) {
	if (argc != 2) {
		printf("usage: kls dir");
		exit(1);
	}
	DIR *dp;
	struct dirent *dep;
	dp = opendir(argv[1]);
	if (dp == NULL) {
		err_msg("opendir err");
	}
	while (dep = readdir(dp)) {
		printf("%s\n", dep->d_name);
	}
	closedir(dp);
	return 0;
}

khead.c 头文件

#include 
#include 
#include 
#include 

extern int errno;

void err_msg(const char* str) {
        printf("%s\n", str);
        printf("errno: %d\terrmsg: %s\n", errno, strerror(errno));
}