/***** **** *** ** *  *   *    *     *       *     *   *  * ** *** **** *****\

    logresolve 2.0 - http://www.net/~tomr/progs/logresolve/

    lr-dbm-flock.h - flock for systems that don't have it in their libraries

    Tom Rathborne - tomr@uunet.ca - http://www.net/~tomr/

\***** **** *** ** *  *   *    *     *       *     *   *  * ** *** **** *****/

#ifndef LR_DBM_FLOCK_H
#define LR_DBM_FLOCK_H

#ifdef LR_NEED_OWN_FLOCK

#define LOCK_SH 1
#define LOCK_EX 2
#define LOCK_NB 4
#define LOCK_UN 8

static int
flock(fd, op)
    int fd, op;
{
    struct flock f;

    bzero(&f, sizeof f);
    switch (op & ~LOCK_NB) {
	case LOCK_EX:
	    f.l_type = F_WRLCK;
	    break;
	case LOCK_SH:
	    f.l_type = F_RDLCK;
	    break;
	case LOCK_UN:
	    f.l_type = F_UNLCK;
	    break;
	default:
	    errno = EINVAL;
	    return -1;
    }
    if (fcntl(fd, (op & LOCK_NB) ? F_SETLK : F_SETLKW, &f) != -1)
	return 0;
    if (errno == EACCES || errno == EAGAIN)
	errno = EWOULDBLOCK;
    return -1;
}

#endif

#endif

/*** end of lr-dbm-flock.h ***/