OPENDIR(3C) Standard C Library Functions OPENDIR(3C)


NAME


opendir, fdopendir - open directory

SYNOPSIS


#include <sys/types.h>
#include <dirent.h>

DIR *opendir(const char *dirname);


DIR *fdopendir(int fildes);


DESCRIPTION


The opendir() function opens a directory stream corresponding to the
directory named by the dirname argument.


The fdopendir() function opens a directory stream for the directory file
descriptor fildes. The directory file descriptor should not be used or
closed following a successful function call, as this might cause
undefined results from future operations on the directory stream obtained
from the call. Use closedir(3C) to close a directory stream.


The directory stream is positioned at the first entry. If the type DIR is
implemented using a file descriptor, applications will only be able to
open up to a total of {OPEN_MAX} files and directories. A successful call
to any of the exec functions will close any directory streams that are
open in the calling process. See exec(2).

RETURN VALUES


Upon successful completion, opendir() and fdopendir() return a pointer to
an object of type DIR. Otherwise, a null pointer is returned and errno is
set to indicate the error.

ERRORS


The opendir() function will fail if:

EACCES
Search permission is denied for the component of the path
prefix of dirname or read permission is denied for
dirname.


ELOOP
Too many symbolic links were encountered in resolving
path.


ENAMETOOLONG
The length of the dirname argument exceeds {PATH_MAX}, or
a path name component is longer than {NAME_MAX} while
{_POSIX_NO_TRUNC} is in effect.


ENOENT
A component of dirname does not name an existing
directory or dirname is an empty string.


ENOTDIR
A component of dirname is not a directory.


The fdopendir() function will fail if:

ENOTDIR
The file descriptor fildes does not reference a directory.


The opendir() function may fail if:

EMFILE
There are {OPEN_MAX} file descriptors currently open in
the calling process.


ENAMETOOLONG
Pathname resolution of a symbolic link produced an
intermediate result whose length exceeds PATH_MAX.


ENFILE
Too many files are currently open on the system.


USAGE


The opendir() and fdopendir() functions should be used in conjunction
with readdir(3C), closedir(3C) and rewinddir(3C) to examine the contents
of the directory (see the EXAMPLES section in readdir(3C)). This method
is recommended for portability.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+------------------------------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+------------------------------------------------+
|Interface Stability | opendir() is Standard; fdopendir() is Evolving |
+--------------------+------------------------------------------------+
|MT-Level | Safe |
+--------------------+------------------------------------------------+

SEE ALSO


lstat(2), symlink(2), closedir(3C), readdir(3C), rewinddir(3C),
scandir(3C), attributes(5)


June 26, 2007 OPENDIR(3C)