opendir(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

OPENDIR(3)              Linux Programmer's Manual             OPENDIR(3)

NAME         top

       opendir, fdopendir - open a directory

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 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.

VERSIONS         top

       fdopendir() is available in glibc since version 2.4.

ATTRIBUTES         top

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

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

CONFORMING TO         top

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

NOTES         top

       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         top

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

COLOPHON         top

       This page is part of release 5.13 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

GNU                            2021-03-22                     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)