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Cream of the Crop 1
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Cream of the Crop 1.iso
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PROGRAM
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CBASE102.ARJ
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CBKEYNEX.C
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1991-09-23
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/* Copyright (c) 1989 Citadel */
/* All Rights Reserved */
/* #ident "@(#)cbkeynex.c 1.5 - 91/09/23" */
#include <ansi.h>
/* ansi headers */
#include <errno.h>
#ifdef AC_STDLIB
#include <stdlib.h>
#endif
#ifdef AC_STRING
#include <string.h>
#endif
/* library headers */
#include <blkio.h>
#include <btree.h>
#include <lseq.h>
/* local headers */
#include "cbase_.h"
/*man---------------------------------------------------------------------------
NAME
cbkeynext - next cbase key
SYNOPSIS
#include <cbase.h>
int cbkeynext(cbp, field)
cbase_t *cbp;
int field;
DESCRIPTION
The cbkeynext function advances the key cursor of the specified
field in cbase cbp by one. The record cursor of cbp is
positioned to the record associated with that key. Other key
cursors are not affected.
cbkeynext 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.
[CBELOCK] cbp is not locked.
[CBENKEY] field is not a key.
[CBENOPEN] cbp is not open.
SEE ALSO
cbkcursor, cbkeyfirst, cbkeylast, cbkeyprev, cbrecnext.
DIAGNOSTICS
Upon successful completion, a value of 0 is returned. Otherwise,
a value of -1 is returned, and errno set to indicate the error.
------------------------------------------------------------------------------*/
#ifdef AC_PROTO
int cbkeynext(cbase_t *cbp, int field)
#else
int cbkeynext(cbp, field)
cbase_t *cbp;
int field;
#endif
{
void *buf = NULL;
cbrpos_t cbrpos = NIL;
lspos_t lspos = NIL;
/* validate arguments */
if (!cb_valid(cbp)) {
errno = EINVAL;
return -1;
}
/* check if not open */
if (!(cbp->flags & CBOPEN)) {
errno = CBENOPEN;
return -1;
}
/* validate arguments */
if (field < 0 || field >= cbp->fldc) {
errno = EINVAL;
return -1;
}
/* check if field not a key */
if (!(cbp->fldv[field].flags & CB_FKEY)) {
errno = CBENKEY;
return -1;
}
/* check if not locked */
if (!(cbp->flags & CBLOCKS)) {
errno = CBELOCK;
return -1;
}
/* set key cursor to next key */
if (btnext(cbp->btpv[field]) == -1) {
CBEPRINT;
return -1;
}
/* check if cursor is null */
if (btcursor(cbp->btpv[field]) == NULL) {
/* set record cursor to null */
if (lssetcur(cbp->lsp, NULL) == -1) {
CBEPRINT;
return -1;
}
return 0;
}
/* get record position */
if (btkeysize(cbp->btpv[field]) != (cbp->fldv[field].len + sizeof(cbrpos_t))) {
CBEPRINT;
errno = CBEPANIC;
return -1;
}
buf = calloc((size_t)1, btkeysize(cbp->btpv[field]));
if (buf == NULL) {
CBEPRINT;
errno = ENOMEM;
return -1;
}
if (btgetk(cbp->btpv[field], buf) == -1) {
CBEPRINT;
free(buf);
return -1;
}
memcpy(&cbrpos, (char *)buf + cbp->fldv[field].len, sizeof(cbrpos));
free(buf);
buf = NULL;
/* set record cursor */
lspos = cbrpos;
if (lssetcur(cbp->lsp, &lspos) == -1) {
CBEPRINT;
return -1;
}
return 0;
}