<?php

/*
 * This file is part of Linfo (c) 2010 Joseph Gillotti.
 * 
 * Linfo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Linfo 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Linfo. If not, see <http://www.gnu.org/licenses/>.
 * 
*/


defined('IN_LINFO') or exit;


/*
 * The BSD os's are largely similar and thus draw from this class.
*/

abstract class OS_BSD_Common extends OS_Unix_Common {
	
	// Store these
	protected
		$settings,
		$exec,
		$error,
		$dmesg,
		$sysctl = array();
	
	// Start us off
	protected function __construct($settings) {

		// Localize settings
		$this->settings = $settings;
		
		// Localize error handler
		$this->error = LinfoError::Singleton();
		
		// Exec running
		$this->exec = new CallExt;

		// Get dmesg
		$this->loadDmesg();
	}
	
	// Save dmesg
	protected function loadDmesg() {
		$this->dmesg = LinfoCommon::getContents('/var/run/dmesg.boot');
	}

	// Use sysctl to get something, and cache result.
	// Also allow getting multiple keys at once, in which case sysctl 
	// will only be called once instead of multiple times (assuming it doesn't break)
	protected function getSysCTL($keys, $do_return = true) {

		// Get the keys as an array, so we can treat it as an array of keys
		$keys = (array) $keys;

		// Store the results of which here
		$results = array();

		// Go through each
		foreach ($keys as $k => $v) {
			$keys[$k] = escapeshellarg($v);
			
			// Check and see if we have any of these already. If so, use previous 
			// values and don't retrive them again
			if (array_key_exists($v, $this->sysctl)) {
				unset($keys[$k]);
				$results[$v] = $this->sysctl[$v];
			}
		}

		// Try running sysctl to get all the values together
		try {
			// Result of sysctl
			$command = $this->exec->exec('sysctl', implode(' ', $keys));

			// Place holder
			$current_key = false;

			// Go through each line
			foreach (explode("\n", $command) as $line) {

				// If this is the beginning of one of the keys' values
				if (preg_match('/^([a-z0-9\.\-\_]+)\s*(?:\:|=)(.+)/', $line, $line_match) == 1) {
					if ($line_match[1] != $current_key) {
						$current_key = $line_match[1];
						$results[$line_match[1]] = trim($line_match[2]);
					}
				}

				// If this line is a continuation of one of the keys' values
				elseif($current_key != false) {
					$results[$current_key] .= "\n".trim($line);
				}
			}
		}

		// Something broke with that sysctl call; try getting
		// all the values separately (slower)
		catch(CallExtException $e) {

			// Go through each
			foreach ($keys as $v) {

				// Try it
				try {
					$results[$v] = $this->exec->exec('sysctl', $v);
				}

				// Didn't work again... just forget it and set value to empty string
				catch (CallExtException $e) {
					$results[$v] = '';
				}
			}
		}

		// Cache these incase they're called upon again
		$this->sysctl = array_merge($results, $this->sysctl);

		// Return an array of all values retrieved, or if just one was 
		// requested, then that one as a string
		if ($do_return)
			return count($results) == 1 ? reset($results) : $results;
	}
}
