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BTSEARCH.C
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1991-09-23
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/* Copyright (c) 1989 Citadel */
/* All Rights Reserved */
/* #ident "@(#)btsearch.c 1.5 - 91/09/23" */
#include <ansi.h>
/* ansi headers */
#include <errno.h>
/* library headers */
#include <blkio.h>
/* local headers */
#include "btree_.h"
/*man---------------------------------------------------------------------------
NAME
btsearch - search a btree
SYNOPSIS
#include <btree.h>
int btsearch(btp, buf)
btree_t *btp;
const void *buf;
DESCRIPTION
The btsearch function searches the btree btp for the key pointed
to by buf. If it is found, the cursor is set to the location of
the key and 1 is returned. If it is not found, the cursor is set
to the next higher key and 0 is returned.
btsearch will fail if one or more of the following is true:
[EINVAL] btp is not a valid btree pointer.
[EINVAL] buf is the NULL pointer.
[BTELOCK] btp is not read locked.
SEE ALSO
btdelcur, btdelete, btinsert.
DIAGNOSTICS
Upon successful completion, a value of 1 is returned if the key
was found or a value of 0 if it was not found. On failure, a
value of -1 is returned, and errno set to indicate the error.
------------------------------------------------------------------------------*/
#ifdef AC_PROTO
int btsearch(btree_t *btp, const void *buf)
#else
int btsearch(btp, buf)
btree_t *btp;
const void *buf;
#endif
{
int found = 0; /* key found flag */
/* validate arguments */
if (!bt_valid(btp) || buf == NULL) {
errno = EINVAL;
return -1;
}
/* check locks */
if (!(btp->flags & BTRDLCK)) {
errno = BTELOCK;
return -1;
}
/* search to position to insert */
found = bt_search(btp, buf);
if (found == -1) {
BTEPRINT;
return -1;
}
/* check if cursor on empty slot */
if (found == 0) {
if (btp->cbtpos.key > btp->cbtnp->n) {
btp->cbtpos.key = btp->cbtnp->n;
if (btnext(btp) == -1) {
BTEPRINT;
return -1;
}
}
}
return found == 1 ? 1: 0;
}