http://coursesweb.net/php-mysql/register-show-online-users-
visitors_t

这是一个不错的教程，正是您所需要的。

注册并显示在线用户和访客

使用MySQL表对在线用户和访问者进行计数在本教程中，您可以学习如何注册，计数并在网页中显示在线用户和访问者的数量。原理是这样的：每个用户/访问者都在文本文件或数据库中注册。每次访问网站页面时，php脚本都会删除所有早于特定时间（例如2分钟）的记录，添加当前用户/访问者，并显示剩余的记录数。

您可以将在线用户和访问者存储在服务器上的文件或MySQL表中。在这种情况下，我认为使用文本文件添加和读取记录要比将它们存储到需要更多请求的MySQL表中更快。

首先，它介绍了在服务器上以文本文件记录的方法，而不是使用MySQL表的方法。

要使用本教程中介绍的脚本下载文件，请单击->计算在线用户和访问者。

•这两个脚本都可以包含在“ .php”文件中（包括include（））， 也可以包含在“
.html”文件中（带有），如您在本页底部的示例中所见；但是服务器必须运行PHP。将在线用户和访客存储在文本文件中

要使用PHP在服务器上的文件中添加记录，必须为该文件设置CHMOD 0766（或CHMOD 0777）权限，以便PHP可以在其中写入数据。

1-在服务器上创建一个文本文件（例如，名为“ userson.txt”），并为其赋予CHMOD
0777权限（在FTP应用程序中，右键单击该文件，选择“属性”，然后选择“读取”，“写入”和“执行”选项） ）。2-创建一个具有以下代码的PHP文件（名为“
usersontxt.php”），然后将此php文件复制到与“ userson.txt”相同的目录中。usersontxt.php的代码

<?php
// Script Online Users and Visitors - http://coursesweb.net/php-mysql/
if(!isset($_SESSION)) session_start();        // start Session, if not already started

$filetxt = 'userson.txt';  // the file in which the online users /visitors are stored
$timeon = 120;             // number of secconds to keep a user online
$sep = '^^';               // characters used to separate the user name and date-time
$vst_id = '-vst-';        // an identifier to know that it is a visitor, not logged user

/*
 If you have an user registration script,
 replace $_SESSION['nume'] with the variable in which the user name is stored.
 You can get a free registration script from:  http://coursesweb.net/php-mysql/register-login-script-users-online_s2
*/

// get the user name if it is logged, or the visitors IP (and add the identifier)

    $uvon = isset($_SESSION['nume']) ? $_SESSION['nume'] : $_SERVER['SERVER_ADDR']. $vst_id;

$rgxvst = '/^([0-9\.]*)'. $vst_id. '/i';         // regexp to recognize the line with visitors
$nrvst = 0;                                       // to store the number of visitors

// sets the row with the current user /visitor that must be added in $filetxt (and current timestamp)

    $addrow[] = $uvon. $sep. time();

// check if the file from $filetxt exists and is writable

    if(is_writable($filetxt)) {
      // get into an array the lines added in $filetxt
      $ar_rows = file($filetxt, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
      $nrrows = count($ar_rows);

            // number of rows

  // if there is at least one line, parse the $ar_rows array

      if($nrrows>0) {
        for($i=0; $i<$nrrows; $i++) {
          // get each line and separate the user /visitor and the timestamp
          $ar_line = explode($sep, $ar_rows[$i]);
      // add in $addrow array the records in last $timeon seconds
          if($ar_line[0]!=$uvon && (intval($ar_line[1])+$timeon)>=time()) {
            $addrow[] = $ar_rows[$i];
          }
        }
      }
    }

$nruvon = count($addrow);                   // total online
$usron = '';                                    // to store the name of logged users
// traverse $addrow to get the number of visitors and users
for($i=0; $i<$nruvon; $i++) {
 if(preg_match($rgxvst, $addrow[$i])) $nrvst++;       // increment the visitors
 else {
   // gets and stores the user's name
   $ar_usron = explode($sep, $addrow[$i]);
   $usron .= '<br/> - <i>'. $ar_usron[0]. '</i>';
 }
}
$nrusr = $nruvon - $nrvst;              // gets the users (total - visitors)

// the HTML code with data to be displayed
$reout = '<div id="uvon"><h4>Online: '. $nruvon. '</h4>Visitors: '. $nrvst. '<br/>Users: '. $nrusr. $usron. '</div>';

// write data in $filetxt
if(!file_put_contents($filetxt, implode("\n", $addrow))) $reout = 'Error: Recording file not exists, or is not writable';

// if access from <script>, with GET 'uvon=showon', adds the string to return into a JS statement
// in this way the script can also be included in .html files
if(isset($_GET['uvon']) && $_GET['uvon']=='showon') $reout = "document.write('$reout');";

echo $reout;             // output /display the result
?>

3-如果要在“ .php”文件中包含上述脚本，请在要显示在线用户和访问者数量的位置添加以下代码：

4-要显示“ .html”文件中的在线访问者/用户数，请使用以下代码：

<script type="text/javascript" src="usersontxt.php?uvon=showon"></script>

该脚本（以及下面提供的其他脚本）与$
_SESSION一起使用。在使用它的PHP文件的开头，必须添加：session_start（）;。使用MySQL表统计在线用户和访客

要在MySQL表中注册，计数和显示在线访问者和用户的数量，需要执行三个SQL查询：删除早于特定时间的记录。使用新用户/
visitor插入一行，或者如果已插入新用户/ visitor，则在其列中更新时间戳。选择其余的行。这是使用MySQL表（名为“
userson”）存储和显示在线用户和访客的脚本代码。

1-首先，我们创建带有两列（uvon，dt）的“ userson”表。在“ uvon”列中存储用户名（如果已登录）或访问者的IP。在“
dt”列中，存储了访问页面时带有时间戳（Unix时间）的数字。-在php文件中添加以下代码（例如，名为“
create_userson.php”）：create_userson.php的代码

<?php
header('Content-type: text/html; charset=utf-8');

// HERE add your data for connecting to MySQ database
$host = 'localhost';           // MySQL server address
$user = 'root';                // User name
$pass = 'password';            // User`s password
$dbname = 'database';          // Database name

// connect to the MySQL server
$conn = new mysqli($host, $user, $pass, $dbname);

// check connection
if (mysqli_connect_errno()) exit('Connect failed: '. mysqli_connect_error());

// sql query for CREATE "userson" TABLE
$sql = "CREATE TABLE `userson` (
 `uvon` VARCHAR(32) PRIMARY KEY,
 `dt` INT(10) UNSIGNED NOT NULL
 ) CHARACTER SET utf8 COLLATE utf8_general_ci";

// Performs the $sql query on the server to create the table
if ($conn->query($sql) === TRUE) echo 'Table "userson" successfully created';
else echo 'Error: '. $conn->error;

$conn->close();
?>

2. - Now we create the script that Inserts, Deletes, and Selects data in the "userson" table (For explanations about the code, see the comments in script).
- Add the code below in another php file (named "usersmysql.php"):
In both file you must add your personal data for connecting to MySQL database, in the variables: $host, $user, $pass, and $dbname .
The code for usersmysql.php

<?php
// Script Online Users and Visitors - coursesweb.net/php-mysql/
if(!isset($_SESSION)) session_start();         // start Session, if not already started

// HERE add your data for connecting to MySQ database
$host = 'localhost';           // MySQL server address
$user = 'root';                // User name
$pass = 'password';            // User`s password
$dbname = 'database';          // Database name

/*
 If you have an user registration script,
 replace $_SESSION['nume'] with the variable in which the user name is stored.
 You can get a free registration script from:  http://coursesweb.net/php-mysql/register-login-script-users-online_s2
*/

// get the user name if it is logged, or the visitors IP (and add the identifier)
$vst_id = '-vst-';         // an identifier to know that it is a visitor, not logged user
$uvon = isset($_SESSION['nume']) ? $_SESSION['nume'] : $_SERVER['SERVER_ADDR']. $vst_id;

$rgxvst = '/^([0-9\.]*)'. $vst_id. '/i';         // regexp to recognize the rows with visitors
$dt = time();                                    // current timestamp
$timeon = 120;             // number of secconds to keep a user online
$nrvst = 0;                                     // to store the number of visitors
$nrusr = 0;                                     // to store the number of usersrs
$usron = '';                                    // to store the name of logged users

// connect to the MySQL server
$conn = new mysqli($host, $user, $pass, $dbname);

// Define and execute the Delete, Insert/Update, and Select queries
$sqldel = "DELETE FROM `userson` WHERE `dt`<". ($dt - $timeon);
$sqliu = "INSERT INTO `userson` (`uvon`, `dt`) VALUES ('$uvon', $dt) ON DUPLICATE KEY UPDATE `dt`=$dt";
$sqlsel = "SELECT * FROM `userson`";

// Execute each query
if(!$conn->query($sqldel)) echo 'Error: '. $conn->error;
if(!$conn->query($sqliu)) echo 'Error: '. $conn->error;
$result = $conn->query($sqlsel);

// if the $result contains at least one row
if ($result->num_rows > 0) {
  // traverse the sets of results and set the number of online visitors and users ($nrvst, $nrusr)
  while($row = $result->fetch_assoc()) {
    if(preg_match($rgxvst, $row['uvon'])) $nrvst++;       // increment the visitors
    else {
      $nrusr++;                   // increment the users
      $usron .= '<br/> - <i>'.$row['uvon']. '</i>';          // stores the user's name
    }
  }
}

$conn->close();                  // close the MySQL connection

// the HTML code with data to be displayed
$reout = '<div id="uvon"><h4>Online: '. ($nrusr+$nrvst). '</h4>Visitors: '. $nrvst. '<br/>Users: '. $nrusr. $usron. '</div>';

// if access from <script>, with GET 'uvon=showon', adds the string to return into a JS statement
// in this way the script can also be included in .html files
if(isset($_GET['uvon']) && $_GET['uvon']=='showon') $reout = "document.write('$reout');";

echo $reout;             // output /display the result
?>

1. 在服务器上创建这两个php文件之后，在浏览器上运行“ create_userson.php”以创建“ userson”表。

2. 在要显示在线用户和访问者数量的php文件中包括“ usersmysql.php”文件。

3. 或者，如果要将其插入到“ .html”文件中，请添加以下代码：

使用这些脚本的示例

•在php文件中包含“ usersontxt.php”：

对抗在线用户和访客

•在HTML文件中包含“ usersmysql.php”：计数器在线用户和访问者

这两个脚本（将数据存储在服务器上的文本文件中或MySQL表中）将显示如下结果：联机：5

访客：3用户：2-MarPlo-Marius