<?php

/**

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements. See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License. You may obtain a copy of the License at

 *

 *       http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/**

 * Log events to a system log using the PHP syslog() function.

 *

 * This appenders requires a layout.

 *

 * ## Configurable parameters: ##

 *

 * - **ident** - The ident of the syslog message.

 * - **priority** - The priority for the syslog message (used when overriding

 *     priority).

 * - **facility** - The facility for the syslog message

 * - **overridePriority** - If set to true, the message priority will always

 *     use the value defined in {@link $priority}, otherwise the priority will

 *     be determined by the message's log level.

 * - **option** - The option value for the syslog message.

 *

 * Recognised syslog options are:

 *

 * - CONS     - if there is an error while sending data to the system logger, write directly to the system console

 * - NDELAY - open the connection to the logger immediately

 * - ODELAY - delay opening the connection until the first message is logged (default)

 * - PERROR - print log message also to standard error

 * - PID    - include PID with each message

 *

 * Multiple options can be set by delimiting them with a pipe character,

 * e.g.: "CONS|PID|PERROR".

 *

 * Recognised syslog priorities are:

 *

 * - EMERG

 * - ALERT

 * - CRIT

 * - ERR

 * - WARNING

 * - NOTICE

 * - INFO

 * - DEBUG

 *

 * Levels are mapped as follows:

 *

 * - <b>FATAL</b> to LOG_ALERT

 * - <b>ERROR</b> to LOG_ERR

 * - <b>WARN</b> to LOG_WARNING

 * - <b>INFO</b> to LOG_INFO

 * - <b>DEBUG</b> to LOG_DEBUG

 * - <b>TRACE</b> to LOG_DEBUG

 *

 * @version $Revision: 1337820 $

 * @package log4php

 * @subpackage appenders

 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0

 * @link http://logging.apache.org/log4php/docs/appenders/syslog.html Appender documentation

 */

class LoggerAppenderSyslog extends LoggerAppender {

    /**

     * The ident string is added to each message. Typically the name of your application.

     *

     * @var string

     */

    protected $ident = "Apache log4php";

    /**

     * The syslog priority to use when overriding priority. This setting is

     * required if {@link overridePriority} is set to true.

     *

     * @var string

     */

    protected $priority;

    /**

     * The option used when opening the syslog connection.

     *

     * @var string

     */

    protected $option = 'PID|CONS';

    /**

     * The facility value indicates the source of the message.

     *

     * @var string

     */

    protected $facility = 'USER';

    /**

     * If set to true, the message priority will always use the value defined

     * in {@link $priority}, otherwise the priority will be determined by the

     * message's log level.

     *

     * @var string

     */

    protected $overridePriority = false;

    /**

     * Holds the int value of the {@link $priority}.

     * @var int

     */

    private $intPriority;

    /**

     * Holds the int value of the {@link $facility}.

     * @var int

     */

    private $intFacility;

    /**

     * Holds the int value of the {@link $option}.

     * @var int

     */

    private $intOption;

    /**

     * Sets the {@link $ident}.

     *

     * @param string $ident

     */

    public function setIdent($ident) {

        $this->ident = $ident;

    }

    /**

     * Sets the {@link $priority}.

     *

     * @param string $priority

     */

    public function setPriority($priority) {

        $this->priority = $priority;

    }

    /**

     * Sets the {@link $facility}.

     *

     * @param string $facility

     */

    public function setFacility($facility) {

        $this->facility = $facility;

    }

    /**

     * Sets the {@link $overridePriority}.

     *

     * @param string $overridePriority

     */

    public function setOverridePriority($overridePriority) {

        $this->overridePriority = $overridePriority;

    }

    /**

     * Sets the 'option' parameter.

     *

     * @param string $option

     */

    public function setOption($option) {

        $this->option = $option;

    }

    /**

     * Returns the 'ident' parameter.

     *

     * @return string $ident

     */

    public function getIdent() {

        return $this->ident;

    }

    /**

     * Returns the 'priority' parameter.

     *

     * @return string

     */

    public function getPriority() {

        return $this->priority;

    }

    /**

     * Returns the 'facility' parameter.

     *

     * @return string

     */

    public function getFacility() {

        return $this->facility;

    }

    /**

     * Returns the 'overridePriority' parameter.

     *

     * @return string

     */

    public function getOverridePriority() {

        return $this->overridePriority;

    }

    /**

     * Returns the 'option' parameter.

     *

     * @return string

     */

    public function getOption() {

        return $this->option;

    }

    public function activateOptions() {

        $this->intPriority = $this->parsePriority();

        $this->intOption = $this->parseOption();

        $this->intFacility = $this->parseFacility();

        $this->closed = false;

    }

    public function close() {

        if ($this->closed != true) {

            closelog();

            $this->closed = true;

        }

    }

    /**

     * Appends the event to syslog.

     *

     * Log is opened and closed each time because if it is not closed, it

     * can cause the Apache httpd server to log to whatever ident/facility

     * was used in openlog().

     *

     * @see http://www.php.net/manual/en/function.syslog.php#97843

     */

    public function append(LoggerLoggingEvent $event) {

        $priority = $this->getSyslogPriority($event->getLevel());

        $message = $this->layout->format($event);

        openlog($this->ident, $this->intOption, $this->intFacility);

        syslog($priority, $message);

        closelog();

    }

    /** Determines which syslog priority to use based on the given level. */

    private function getSyslogPriority(LoggerLevel $level) {

        if ($this->overridePriority) {

            return $this->intPriority;

        }

        return $level->getSyslogEquivalent();

    }

    /** Parses a syslog option string and returns the correspodning int value. */

    private function parseOption() {

        $value = 0;

        $options = explode('|', $this->option);

        foreach ($options as $option) {

            if (!empty($option)) {

                $constant = "LOG_" . trim($option);

                if (defined($constant)) {

                    $value |= constant($constant);

                } else {

                    trigger_error("log4php: Invalid syslog option provided: $option. Whole option string: {$this->option}.", E_USER_WARNING);

                }

            }

        }

        return $value;

    }

    /** Parses the facility string and returns the corresponding int value. */

    private function parseFacility() {

        if (!empty($this->facility)) {

            $constant = "LOG_" . trim($this->facility);

            if (defined($constant)) {

                return constant($constant);

            } else {

                trigger_error("log4php: Invalid syslog facility provided: {$this->facility}.", E_USER_WARNING);

            }

        }

    }

    /** Parses the priority string and returns the corresponding int value. */

    private function parsePriority() {

        if (!empty($this->priority)) {

            $constant = "LOG_" . trim($this->priority);

            if (defined($constant)) {

                return constant($constant);

            } else {

                trigger_error("log4php: Invalid syslog priority provided: {$this->priority}.", E_USER_WARNING);

            }

        }

    }

}