后台推送php实现程序

<?php require 'config.php'; require 'fun.php'; $db = mysqli_connect($db_host, $db_user, $db_password, $db_name); if(!$db) show404(); mysqli_set_charset($db, 'utf8'); register_shutdown_function('beyond_time'); set_time_limit($max_time_pushing); error_reporting(0); $what = ''; $done = false; while(!$what) { $sql = 'select * from chat where id='.$_COOKIE['chatid']; $result = mysqli_query($db, $sql); if(mysqli_num_rows($result) == 0) { $done = true; show404(); } mysqli_free_result($result); $sql = 'select * from sentence where chat_id='.$_COOKIE['chatid'].' and time>\''.$_COOKIE['time'].'\' or time=\''.$_COOKIE['time'].'\''; mysqli_query($db, 'lock tables sentence WRITE'); $result = mysqli_query($db, $sql); if(mysqli_num_rows($result) > 0) { while(($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) != null) { $word = '<p class="line"><span style="color:blue;">'; $word .= ($row['speaker'] == $_COOKIE['speaker']) ? 'YOU:' : 'TA :'; $word .= '</span>'.$row['content'].'</p>'; $what .= $word; if($row['got'] > 0) $sql = 'delete from sentence where id='.$row['id']; else $sql = 'update sentence set got=got+1 where id='.$row['id']; mysqli_query($db, $sql); $time = $row['time']; } setcookie('time', $time); } mysqli_query($db, 'unlock tables'); mysqli_free_result($result); } mysqli_close($db); echo $what; function beyond_time() { if($GLOBALS['db'] && !$GLOBALS['what']) { if(!$done) { $sql = 'delete from chat where id='.$_COOKIE['chatid']; mysqli_query($GLOBALS['db'], $sql); } mysqli_close($GLOBALS['db']); } } ?>