cbgetrf.cpp

来自「CBASE v1.01 采用Borland公司TC++编写的数据库管理源程序库」· C++ 代码 · 共 92 行

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

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

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

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

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

/*man---------------------------------------------------------------------------
NAME
     cbgetrf - get cbase record field

SYNOPSIS
     #include <cbase.h>

     int cbgetrf(cbp, field, buf)
     cbase_t *cbp;
     int field;
     void *buf;

DESCRIPTION
     The cbgetrf function reads the specified field from the current
     record of cbase cbp into buf.  buf must point to a storage area
     of size no less than the size of the specified field.

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

     [EINVAL]       cbp is not a valid cbase pointer.
     [EINVAL]       field is not a valid field number for
                    cbase cbp.
     [EINVAL]       buf is the NULL pointer.
     [CBELOCK]      cbp is not read locked.
     [CBENOPEN]     cbp is not open.
     [CBENREC]      The record cursor for cbp is null.

SEE ALSO
     cbcursor, cbgetr, cbputrf.

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 cbgetrf(cbase_t *cbp, int field, void *buf)
{
	/* validate arguments */
	if (!cb_valid(cbp) || buf == NULL) {
		errno = EINVAL;
		return -1;
	}

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

	/* validate field argument */
	if (field < 0 || field >= cbp->fldc) {
		errno = EINVAL;
		return -1;
	}

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

	/* check if cursor is null */
	if (lscursor(cbp->lsp) == NULL) {
		errno = CBENREC;
		return -1;
	}

	/* read field */
	if (lsgetrf(cbp->lsp, cbp->fldv[field].offset, buf, cbp->fldv[field].len) == -1) {
		CBEPRINT;
		return -1;
	}

	errno = 0;
	return 0;
}