opendir(3)                 Library Functions Manual                 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.

       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   |
       +--------------------------------------------+---------------+---------+
       |opendir (), fdopendir ()                    | 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)

Linux man-pages 6.7               2023-10-31                        opendir(3)