usr/src/sys/stand.att/lseek.c

/*-
 * Copyright (c) 1982, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.proprietary.c%
 *
 *      @(#)lseek.c     8.1 (Berkeley) %G%
 */

#include <sys/param.h>
#include <stand.att/saio.h>

off_t
lseek(fdesc, addr, ptr)
        int fdesc, ptr;
        off_t addr;
{
        register struct iob *io;

#ifndef SMALL
        if (ptr != L_SET) {
                printf("Seek not from beginning of file\n");
                errno = EOFFSET;
                return (-1);
        }
#endif
        fdesc -= 3;
#ifndef SMALL
        if (fdesc < 0 || fdesc >= SOPEN_MAX ||
            ((io = &iob[fdesc])->i_flgs & F_ALLOC) == 0) {
                errno = EBADF;
                return (-1);
        }
#endif
        io->i_offset = addr;
        io->i_bn = addr / DEV_BSIZE;
        io->i_cc = 0;
        return (0);
}