OPENDIR(3C)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 direc‐
tory 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 con‐
tents 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 ALSOlstat(2), symlink(2), closedir(3C), readdir(3C), rewinddir(3C), scan‐
dir(3C), attributes(5)
Jun 26, 2007 OPENDIR(3C)