opendir(3) - Linux manual page (original) (raw)

opendir(3) Library Functions Manual opendir(3)

NAME top

   opendir, fdopendir - open a directory

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#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 top

   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 top

   The **opendir**() and **fdopendir**() functions return a pointer to the
   directory stream.  On error, NULL is returned, and _[errno](../man3/errno.3.html)_ is set to
   indicate the error.

ERRORS top

   **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 top

   For an explanation of the terms used in this section, see
   [attributes(7)](../man7/attributes.7.html).
   ┌──────────────────────────────────────┬───────────────┬─────────┐
   │ **Interface** │ **Attribute** │ **Value** │
   ├──────────────────────────────────────┼───────────────┼─────────┤
   │ **opendir**(), **fdopendir**()               │ Thread safety │ MT-Safe │
   └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS top

   POSIX.1-2008.

STANDARDS top

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

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

NOTES top

   Filename entries can be read from a directory stream using
   [readdir(3)](../man3/readdir.3.html).

   The underlying file descriptor of the directory stream can be
   obtained using [dirfd(3)](../man3/dirfd.3.html).

   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 top

   [open(2)](../man2/open.2.html), [closedir(3)](../man3/closedir.3.html), [dirfd(3)](../man3/dirfd.3.html), [readdir(3)](../man3/readdir.3.html), [rewinddir(3)](../man3/rewinddir.3.html),
   [scandir(3)](../man3/scandir.3.html), [seekdir(3)](../man3/seekdir.3.html), [telldir(3)](../man3/telldir.3.html)

COLOPHON top

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   man-pages@man7.org

Linux man-pages 6.10 2024-07-23 opendir(3)

Pages that refer to this page:close_range(2), execve(2), fanotify_mark(2), fork(2), open(2), closedir(3), dirfd(3), fts(3), getdirentries(3), glob(3), readdir(3), rewinddir(3), scandir(3), seekdir(3), telldir(3)