opendir(3)

NAME

   opendir, fdopendir - open a directory

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:
           _XOPEN_SOURCE >= 700 || _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
   appropriately.

ERRORS

   EACCES Permission denied.

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

   EMFILE Too many file descriptors in use by process.

   ENFILE Too many files are currently open in the system.

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

   ENOMEM Insufficient memory to complete the operation.

   ENOTDIR
          name is not a directory.

VERSIONS

   fdopendir() is available in glibc since version 2.4.

ATTRIBUTES

   For an explanation of the terms used in this section, see
   attributes(7).

   ┌───────────────────────┬───────────────┬─────────┐
   │Interface              │ Attribute     │ Value   │
   ├───────────────────────┼───────────────┼─────────┤
   │opendir(), fdopendir() │ Thread safety │ MT-Safe │
   └───────────────────────┴───────────────┴─────────┘

CONFORMING TO

   opendir() is present on SVr4, 4.3BSD, and specified in POSIX.1-2001.
   fdopendir() is specified in POSIX.1-2008.

NOTES

   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.