Embedded Linux system Programming (v)--Directory file functions

embedded Linux system Programming (v)--directory file functions

directories in Linux are also files, and directory manipulation functions are standard IO library functions. The main functions are as follows:

#include <sys/types.h>

#include <dirent.h>

DIR *opendir (const char *name);

DIR *fdopendir (int fd);

Successfully returns a pointer to the directory stream, fails to return NULL, and sets the errno global variable.

#include <dirent.h>

struct Dirent *readdir (DIR *dirp);

A pointer to the directory dirent structure is returned successfully, if the end of the directory stream is reached or the error returns NULL.

#include <dirent.h>

int Scandir (const char *dirp,// directory name

struct dirent ***namelist,// return directory list

Int (*filter) (const struct dirent *),// filter directory,NULL not filtered

Int (*compar) (const struct dirent **,const struct dirent * *));// Sort return directory,NULL not sorted

The number of files successfully returned in the directory, failed to return -1.

Directory file information structure body dirent:

struct Dirent {

ino_t D_ino; /* inode number */

off_t D_off; /* Offset to the next dirent */

unsigned short d_reclen; /* Length of this record */

unsigned char d_type; /* type of file; Not supported

By all file system types */

Char d_name[256]; /* FileName */

};

To traverse a directory function:

int Traverse_dir (const char *path)

{

struct Dirent **dent;

unsigned int i = 0;

i = scandir (path, &dent, NULL, NULL);

while (*dent)

{

printf ("%s\n", (*dent)->d_name);

dent++;

}

return 0;

}

This article from "Endless life, Struggle not only" blog, reprint please contact the author!

Embedded Linux system Programming (v)--Directory file functions