redhat man page for readdir

READDIR(2)						     Linux Programmer's Manual							READDIR(2)

NAME
       readdir - read directory entry

SYNOPSIS
       #include <unistd.h>
       #include <linux/dirent.h>
       #include <linux/unistd.h>

       _syscall3(int, readdir, uint, fd, struct dirent *, dirp, uint, count);

       int readdir(unsigned int fd, struct dirent *dirp, unsigned int count);

DESCRIPTION
       This  is not the function you are interested in.  Look at readdir(3) for the POSIX conforming C library interface.  This page documents the
       bare kernel system call interface, which can change, and which is superseded by getdents(2).

       readdir reads one dirent structure from the directory pointed at by fd into the memory area pointed to by dirp.	 The  parameter  count	is
       ignored; at most one dirent structure is read.

       The dirent structure is declared as follows:

	      struct dirent
	      {
		  long d_ino;		      /* inode number */
		  off_t d_off;		      /* offset to this dirent */
		  unsigned short d_reclen;    /* length of this d_name */
		  char d_name [NAME_MAX+1];   /* file name (null-terminated) */
	      }

       d_ino  is  an  inode  number.   d_off  is the distance from the start of the directory to this dirent.  d_reclen is the size of d_name, not
       counting the null terminator.  d_name is a null-terminated file name.

RETURN VALUE
       On success, 1 is returned.  On end of directory, 0 is returned.	On error, -1 is returned, and errno is set appropriately.

ERRORS
       EBADF  Invalid file descriptor fd.

       EFAULT Argument points outside the calling process's address space.

       EINVAL Result buffer is too small.

       ENOENT No such directory.

       ENOTDIR
	      File descriptor does not refer to a directory.

CONFORMING TO
       This system call is Linux specific.

SEE ALSO
       getdents(2), readdir(3)

Linux 1.3.6							    1995-07-22								READDIR(2)