da_read_capacity.c

使用libscsi做的一系列cdrom操作工具程序。包含cdwrite,cdflush,cdda三个程序

/*
  da_read_capacity -- read drive capacity
  Copyright (C) 1996 Dieter Baron and Armin Obersteiner

  This file is part of libscsi, a library for direct scsi device access
  The authors can be contacted at
	<[e-mail]>
	<[e-mail]>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <scsi/cd.h>



int
sc_da_read_capacity(SCSI *fd, u_long *lba, u_long *bl, int pmi)
{
    static unsigned char cmd[10] = { 0x25 };
    unsigned char b[8];
    int result;

    if (pmi) {
	cmd[8] = 1;
	sc_store_l(cmd+2, *lba);
    }
    else
	memset(cmd+2, 0, 8);

    if ((result=sc_send(fd, SC_READ, 10, cmd, 8, b)) >= 0) {
	sc_fetch_l(*lba, b);
	sc_fetch_l(*bl, b+4);
    }

    return result;
}