Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

** without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

** See the GNU Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#include "zbxexpression.h"

​

#include "zbxnum.h"

#include "zbxvariant.h"

#include "zbxexpr.h"

#include "zbxalgo.h"

​

/******************************************************************************

 *                                                                            *

 *                     Module for evaluating expressions                      *

 *                  ---------------------------------------                   *

 *                                                                            *

 * Global variables are used for efficiency reasons so that arguments do not  *

 * have to be passed to each of evaluate_termX() functions. For this reason,  *

 * too, this module is isolated into a separate file.                         *

 *                                                                            *

 * The priority of supported operators is as follows:                         *

 *                                                                            *

 *   - (unary)   evaluate_term8()                                             *

 *   not         evaluate_term7()                                             *

 *   * /         evaluate_term6()                                             *

 *   + -         evaluate_term5()                                             *

 *   < <= >= >   evaluate_term4()                                             *

 *   = <>        evaluate_term3()                                             *

 *   and         evaluate_term2()                                             *

 *   or          evaluate_term1()                                             *

 *                                                                            *

 * Function evaluate_term9() is used for parsing tokens on the lowest level:  *

 * those can be suffixed numbers like "12.345K" or parenthesized expressions. *

 *                                                                            *

 ******************************************************************************/

​

static const char   *ptr;       /* character being looked at */

static int      level;      /* expression nesting level  */

​

static char     *buffer;    /* error message buffer      */

static size_t       max_buffer_len; /* error message buffer size */

​

/******************************************************************************

 *                                                                            *

 * Purpose: check whether the character delimits a numeric token.             *

 *                                                                            *

 ******************************************************************************/

static int  is_number_delimiter(char c)

{

    return 0 == isdigit(c) && '.' != c && 0 == isalpha(c) ? SUCCEED : FAIL;

}

​

/******************************************************************************