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readdir

NAME

readdir - read a directory

SYNOPSIS

#include <sys/types.h>
#include <dirent.h>
struct dirent *readdir(DIR *dir);

DESCRIPTION

The readdir() function returns a pointer to a dirent structure representing the next directory entry in the directory stream pointed to by dir. It returns NULL on reaching the end-of-file or if an error occurred.

On Linux, the dirent structure is defined as follows:

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 */
    char           d_name[256]; /* filename */
};

According to POSIX, the dirent structure contains a field char d_name[] of unspecified size, with at most NAME_MAX characters preceding the terminating null byte. POSIX.1-2001 also documents the field ino_t d_ino as an XSI extension. Use of other fields will harm the portability of your programs.

The data returned by readdir() may be overwritten by subsequent calls to readdir() for the same directory stream.

RETURN VALUE

The readdir() function returns a pointer to a dirent structure, or NULL if an error occurs or end-of-file is reached. On error, errno is set appropriately.

ERRORS

EBADF

Invalid directory stream descriptor dir.

CONFORMING TO

SVr4, 4.3BSD, POSIX.1-2001

SEE ALSO

read(2), closedir(3), dirfd(3), ftw(3), opendir(3), rewinddir(3), scandir(3), seekdir(3), telldir(3)