cbreclas.cpp

CBASE v1.01 采用Borland公司TC++编写的数据库管理源程序库

/*	Copyright (c) 1989 Citadel	*/
/*	   All Rights Reserved    	*/

/* #ident	"@(#)cbreclas.c	1.4 - 90/06/20" */

/* ansi headers */
#include <errno.h>

/* library headers */
#include "lseq.h"

/* local headers */
#include "cbase_.h"

/*man---------------------------------------------------------------------------
NAME
     cbreclast - last cbase record

SYNOPSIS
     #include <cbase.h>

     int cbreclast(cbp)
     cbase_t *cbp;

DESCRIPTION
     The cbreclast function positions the record cursor of cbase cbp
     on the last record.

     cbreclast will fail if one or more of the following is true:

     [EINVAL]       cbp is not a valid cbase pointer.
     [CBELOCK]      cbp is not locked.
     [CBENOPEN]     cbp is not open.
     [CBENREC]      cbp is empty.

SEE ALSO
     cbreccnt, cbrecfirst, cbrecnext, cbrecprev.

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Otherwise,
     a value of -1 is returned, and errno set to indicate the error.

------------------------------------------------------------------------------*/
int cbreclast(cbase_t *cbp)
{
	/* validate arguments */
	if (!cb_valid(cbp)) {
		errno = EINVAL;
		return -1;
	}

	/* check if not open */
	if (!(cbp->flags & CBOPEN)) {
		errno = CBENOPEN;
		return -1;
	}

	/* check if not locked */
	if (!(cbp->flags & CBLOCKS)) {
		errno = CBELOCK;
		return -1;
	}

	/* check if cbp is empty */
	if (lsreccnt(cbp->lsp) == 0) {
		errno = CBENREC;
		return -1;
	}

	/* set cursor to last record */
	if (lslast(cbp->lsp) == -1) {
		CBEPRINT;
		return -1;
	}

	errno = 0;
	return 0;
}