opendir(3)

NAME
opendir, fdopendir - open a directory

LIBRARY
Standard C library (libc, -lc)

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

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

    Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

fdopendir():
    Since glibc 2.10:
        _POSIX_C_SOURCE >= 200809L
    Before glibc 2.10:
        _GNU_SOURCE

DESCRIPTION
The opendir() function opens a directory stream corresponding to the directory name, and returns a pointer to the directory stream. The stream is positioned at the first entry in the directory.

The fdopendir() function is like opendir(), but returns a directory stream for the directory referred to by the open file descriptor fd. After a successful call to fdopendir(), fd is used internally by the implementation, and should not otherwise be used by the application.

RETURN VALUE
The opendir() and fdopendir() functions return a pointer to the directory stream. On error, NULL is returned, and errno is set to indicate the error.

ERRORS

EACCES
    Permission denied.

EBADF
    fd is not a valid file descriptor opened for reading.

EMFILE
    The per-process limit on the number of open file descriptors has been reached.

ENAMETOOLONG
    name was too long.

ENFILE
    The system-wide limit on the total number of open files has been reached.

ENOENT
    Directory does not exist, or name is an empty string.

ENOMEM
    Insufficient memory to complete the operation.

ENOTDIR
    name is not a directory.

ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value
 | Thread safety | MT-Safe

STANDARDS
POSIX.1-2008.

STANDARDS

opendir()
    SVr4, 4.3BSD, POSIX.1-2001.

fdopendir()
    POSIX.1-2008. glibc 2.4.

NOTES
Filename entries can be read from a directory stream using readdir(3).

The underlying file descriptor of the directory stream can be obtained using dirfd(3).

The opendir() function sets the close-on-exec flag for the file descriptor underlying the DIR *. The fdopendir() function leaves the setting of the close-on-exec flag unchanged for the file descriptor, fd. POSIX.1-200x leaves it unspecified whether a successful call to fdopendir() will set the close-on-exec flag for the file descriptor, fd.

SEE ALSO
open(2), closedir(3), dirfd(3), readdir(3), rewinddir(3), scandir(3), seekdir(3), telldir(3)