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GETDIRENTRIES(2)	  FreeBSD System Calls Manual	      GETDIRENTRIES(2)

NAME
     getdirentries, getdents --	get directory entries in a file	system inde-
     pendent format

LIBRARY
     Standard C	Library	(libc, -lc)

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

     int
     getdirentries(int fd, char	*buf, int nbytes, long *basep);

     int
     getdents(int fd, char *buf, int nbytes);

DESCRIPTION
     The getdirentries() and getdents()	system calls read directory entries
     from the directory	referenced by the file descriptor fd into the buffer
     pointed to	by buf,	in a file system independent format.  Up to nbytes of
     data will be transferred.	The nbytes argument must be greater than or
     equal to the block	size associated	with the file, see stat(2).  Some file
     systems may not support these system calls	with buffers smaller than this
     size.

     The data in the buffer is a series	of dirent structures each containing
     the following entries:

	   u_int32_t d_fileno;
	   u_int16_t d_reclen;
	   u_int8_t  d_type;
	   u_int8_t  d_namlen;
	   char	   d_name[MAXNAMELEN + 1]; /* see below	*/

     The d_fileno entry	is a number which is unique for	each distinct file in
     the file system.  Files that are linked by	hard links (see	link(2)) have
     the same d_fileno.	 The d_reclen entry is the length, in bytes, of	the
     directory record.	The d_type entry is the	type of	the file pointed to by
     the directory record.  The	file type values are defined in
     _sys/dirent.h_.  The d_name entry contains	a null terminated file name.
     The d_namlen entry	specifies the length of	the file name excluding	the
     null byte.	 Thus the actual size of d_name	may vary from 1	to MAXNAMELEN
     + 1.

     Entries may be separated by extra space.  The d_reclen entry may be used
     as	an offset from the start of a dirent structure to the next structure,
     if	any.

     The actual	number of bytes	transferred is returned.  The current position
     pointer associated	with fd	is set to point	to the next block of entries.
     The pointer may not advance by the	number of bytes	returned by
     getdirentries() or	getdents().  A value of	zero is	returned when the end
     of	the directory has been reached.

     The getdirentries() system	call writes the	position of the	block read
     into the location pointed to by basep.  Alternatively, the	current	posi-
     tion pointer may be set and retrieved by lseek(2).	 The current position
     pointer should only be set	to a value returned by lseek(2), a value
     returned in the location pointed to by basep (getdirentries() only) or
     zero.

RETURN VALUES
     If	successful, the	number of bytes	actually transferred is	returned.
     Otherwise,	-1 is returned and the global variable errno is	set to indi-
     cate the error.

ERRORS
     The getdirentries() system	call will fail if:

     [EBADF]		The fd argument	is not a valid file descriptor open
			for reading.

     [EFAULT]		Either buf or basep point outside the allocated
			address	space.

     [EINVAL]		The file referenced by fd is not a directory, or
			nbytes is too small for	returning a directory entry or
			block of entries, or the current position pointer is
			invalid.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

SEE ALSO
     lseek(2), open(2)

HISTORY
     The getdirentries() system	call first appeared in 4.4BSD.	The getdents()
     system call first appeared	in FreeBSD 3.0.

FreeBSD	10.1			  May 3, 1995			  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | HISTORY

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