DIRFD(3C) Standard C Library Functions DIRFD(3C)

NAME

dirfd - get directory stream file descriptor

SYNOPSIS

#include <dirent.h>

int dirfd(DIR *dir);

DESCRIPTION

The dirfd() function returns the file descriptor associated with the
directory stream dir.


This file descriptor is the one used internally by the directory stream
operations. See opendir(3C), closedir(3C), readdir(3C), rewinddir(3C),
seekdir(3C), telldir(3C). The file descriptor is automatically closed
when closedir() is called for the directory stream dir or when one of the
exec functions is called. See exec(2).


The file descriptor can safely be used only by functions that do not
depend on or alter the file position, such as fstat(2) and fchdir(2).
Closing the file descriptor with close(2) or modifying the file position
by means other than the directory stream operations listed above causes
undefined behavior to occur when one of the directory stream operations
is subsequently called with the directory stream dir.

RETURN VALUES

Upon successful completion, the dirfd() function returns an open file
descriptor for the directory associated with the directory stream dir.

ERRORS

There are no defined error returns. Passing an invalid directory stream
as an argument to the dirfd() function results in undefined behavior.

USAGE

The dirfd() function is intended to be used to obtain a file descriptor
for use with the fchdir() function.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Committed |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+

SEE ALSO

close(2), exec(2), fchdir(2), fstat(2), closedir(3C), opendir(3C),
readdir(3C), rewinddir(3C), seekdir(3C), telldir(3C), attributes(7)


October 24, 2007 DIRFD(3C)