| HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |  |
| NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | STANDARDS | STANDARDS | NOTES | SEE ALSO | COLOPHON | |
| |
opendir(3) Library Functions Manual opendir(3) opendir, fdopendir - open a directory
Standard C library (libc, -lc)
#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
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.
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.
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.
For an explanation of the terms used in this section, see attributes(7). ┌──────────────────────────────────────┬───────────────┬─────────┐ │ Interface │ Attribute │ Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │ opendir(), fdopendir() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘
POSIX.1-2008.
opendir() SVr4, 4.3BSD, POSIX.1-2001. fdopendir() POSIX.1-2008. glibc 2.4.
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.
open(2), closedir(3), dirfd(3), readdir(3), rewinddir(3), scandir(3), seekdir(3), telldir(3)
This page is part of the man-pages (Linux kernel and C library user-space interface documentation) project. Information about the project can be found at ⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report for this manual page, see ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩. This page was obtained from the tarball man-pages-6.15.tar.gz fetched from ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on 2025-08-11. If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up- to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to man-pages@man7.org Linux man-pages 6.15 2025-05-17 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)
| HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. | |