Zabbix

<?php

/*

** 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/>.

**/

​

​

abstract class CParser {

​

    const PARSE_FAIL = -1;

    const PARSE_SUCCESS = 0;

    const PARSE_SUCCESS_CONT = 1;

​

    protected $length = 0;

    protected $match = '';

    protected $error_source = false;

    protected $error_pos = 0;

    protected $error_msgs = [

        'empty' => 'string is empty',

        'unexpected_end' => 'unexpected end of string'

    ];

​

    /**

     * Try to parse the string starting from the given position.

     *

     * @param string    $source     string to parse

     * @param int       $pos        position to start from

     *

     * @return int

     */

    abstract public function parse($source, $pos = 0);

​

    /**

     * Returns length of the parsed element.

     *

     * @return int

     */

    public function getLength() {

        return $this->length;

    }

​

    /**

     * Returns parsed element.

     *

     * @return string

     */

    public function getMatch() {

        return $this->match;

    }

​

    /**

     * Returns the error message if string is invalid.

     *

     * @return string

     */

    public function getError(): string {

        if ($this->error_source === false) {

            return '';

        }

​

        if (!isset($this->error_source[$this->error_pos])) {

            return ($this->error_pos == 0) ? $this->error_msgs['empty'] : $this->error_msgs['unexpected_end'];

        }

​

        // The error message is prepared here to avoid extra calculations if the error message is not used.

        return $this->errorPosMessage($this->error_source, $this->error_pos);

    }

​

    /**

     * Save error source string and position for later use, when error will be retrieved.

     *

     * @param string $source

     * @param int $pos

     */

    protected function errorPos($source, $pos): void {

        $this->error_source = $source;

        $this->error_pos = $pos;

    }

​

    /**

     * Clears error, when parse is used multiple times with same parser.

     */