OPENDIR(3) Linux Programmer's Manual OPENDIR(3)
opendir, fdopendir - open a directory
DIR *opendir(const char *name);
DIR *fdopendir(int fd);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Since glibc 2.10:
_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
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 fdopendir() function is like opendir(), but returns a directory stream for the direc-
tory 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
The opendir() and fdopendir() functions return a pointer to the directory stream. On
error, NULL is returned, and errno is set appropriately.
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.
name is not a directory.
fdopendir() is available in glibc since version 2.4.
opendir() is present on SVr4, 4.3BSD, and specified in POSIX.1-2001. fdopendir() is spec-
ified in POSIX.1-2008.
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),
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GNU 2010-06-20 OPENDIR(3)