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,structdirent*,dirp,uint,count);
intreaddir(unsignedint fd,structdirent*dirp,unsignedint 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kernel system call interface, which can change, and which is superseded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.
RETURNVALUE
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.
CONFORMINGTO
This system call is Linux specific.
SEEALSO
getdents(2), readdir(3)
Linux 1.3.6 1995-07-22 READDIR(2)
Take our 
