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DIRECTORY(3)	       FreeBSD Library Functions Manual		  DIRECTORY(3)

NAME
     opendir, fdopendir, readdir, readdir_r, telldir, seekdir, rewinddir,
     closedir, fdclosedir, dirfd -- directory operations

LIBRARY
     Standard C	Library	(libc, -lc)

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

     DIR *
     opendir(const char	*filename);

     DIR *
     fdopendir(int fd);

     struct dirent *
     readdir(DIR *dirp);

     int
     readdir_r(DIR *dirp, struct dirent	*entry,	struct dirent **result);

     long
     telldir(DIR *dirp);

     void
     seekdir(DIR *dirp,	long loc);

     void
     rewinddir(DIR *dirp);

     int
     closedir(DIR *dirp);

     int
     fdclosedir(DIR *dirp);

     int
     dirfd(DIR *dirp);

DESCRIPTION
     The opendir() function opens the directory	named by filename, associates
     a directory stream	with it	and returns a pointer to be used to identify
     the directory stream in subsequent	operations.  The pointer NULL is
     returned if filename cannot be accessed, or if it cannot malloc(3)	enough
     memory to hold the	whole thing.

     The fdopendir() function is equivalent to the opendir() function except
     that the directory	is specified by	a file descriptor fd rather than by a
     name.  The	file offset associated with the	file descriptor	at the time of
     the call determines which entries are returned.

     Upon successful return from fdopendir(), the file descriptor is under the
     control of	the system, and	if any attempt is made to close	the file
     descriptor, or to modify the state	of the associated description other
     than by means of closedir(), readdir(), readdir_r(), or rewinddir(), the
     behavior is undefined.  Upon calling closedir() the file descriptor is
     closed.  The FD_CLOEXEC flag is set on the	file descriptor	by a success-
     ful call to fdopendir().

     The readdir() function returns a pointer to the next directory entry.  It
     returns NULL upon reaching	the end	of the directory or on error.  In the
     event of an error,	errno may be set to any	of the values documented for
     the getdirentries(2) system call.

     The readdir_r() function provides the same	functionality as readdir(),
     but the caller must provide a directory entry buffer to store the results
     in.  If the read succeeds,	result is pointed at the entry;	upon reaching
     the end of	the directory result is	set to NULL.  The readdir_r() function
     returns 0 on success or an	error number to	indicate failure.

     The telldir() function returns a token representing the current location
     associated	with the named directory stream.  Values returned by telldir()
     are good only for the lifetime of the DIR pointer,	dirp, from which they
     are derived.  If the directory is closed and then reopened, prior values
     returned by telldir() will	no longer be valid.

     The seekdir() function sets the position of the next readdir() operation
     on	the directory stream.  The new position	reverts	to the one associated
     with the directory	stream when the	telldir() operation was	performed.
     State associated with the token returned by telldir(is, freed, when, it,
     is, passed, to) seekdir().	 If you	wish return to the same	location
     again, then you must create a new token with another telldir() call.

     The rewinddir() function resets the position of the named directory
     stream to the beginning of	the directory.

     The closedir() function closes the	named directory	stream and frees the
     structure associated with the dirp	pointer, returning 0 on	success.  On
     failure, -1 is returned and the global variable errno is set to indicate
     the error.

     The fdclosedir() function is equivalent to	the closedir() function	except
     that this function	returns	directory file descriptor instead of closing
     it.

     The dirfd() function returns the integer file descriptor associated with
     the named directory stream, see open(2).

     Sample code which searches	a directory for	entry ``name'' is:

	   dirp	= opendir(".");
	   if (dirp == NULL)
		   return (ERROR);
	   len = strlen(name);
	   while ((dp =	readdir(dirp)) != NULL)	{
		   if (dp->d_namlen == len && strcmp(dp->d_name, name) == 0) {
			   (void)closedir(dirp);
			   return (FOUND);
		   }
	   }
	   (void)closedir(dirp);
	   return (NOT_FOUND);

SEE ALSO
     close(2), lseek(2), open(2), read(2), dir(5)

HISTORY
     The opendir(), readdir(), telldir(), seekdir(), rewinddir(), closedir(),
     and dirfd() functions appeared in 4.2BSD.	The fdopendir()	function
     appeared in FreeBSD 8.0.  fdclosedir() function appeared in FreeBSD 10.0.

BUGS
     The invalidation of telldir() tokens when calling seekdir() is non-stan-
     dard.

FreeBSD	9.3			August 18, 2013			   FreeBSD 9.3

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY | BUGS

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