lseek.c

guide and some example with visualC++

/* lseek.c -- move read/write pointer.
 *
 * Copyright (c) 1995 Cygnus Support
 *
 * The authors hereby grant permission to use, copy, modify, distribute,
 * and license this software and its documentation for any purpose, provided
 * that existing copyright notices are retained in all copies and that this
 * notice is included verbatim in any distributions. No written agreement,
 * license, or royalty fee is required for any of the authorized uses.
 * Modifications to this software may be copyrighted by their authors
 * and need not follow the licensing terms described here, provided that
 * the new terms are clearly indicated on the first page of each file where
 * they apply.
 */
#include <sys/types.h>
#include <errno.h>
#include "glue.h"

/*
 * lseek --  Since a serial port is non-seekable, we return an error.
 */
off_t
_DEFUN (lseek, (fd,  offset, whence),
       int fd _AND
       off_t offset _AND
       int whence)
{
  #ifdef debuglg
  prs("[lseek]\n");
  inbyte();
  #endif
  SET_ERRNO (ESPIPE); 
  return ((off_t)-1);
}