Running Linux Commands through PHP

I have prepared a module that will show the CPU utilization, current processes, memory utilization and disk quota of a remote system when asked on a PHP page

Below is the syntax and code in PHP and HTML just copy and paste it on the desired directory.

<table width="900" border="0" cellpadding="3" cellspacing="3">

<tr bgcolor="#666666">

    <td align="center"><font color="#FFFFFF"><b><h1><?php system("hostname"); ?></h1></b></font></td>

  </tr>

  <tr bgcolor="#000000">

    <td><font color="#FFFFFF"><b>Uptime:</b></font></td>

  </tr>

  <tr bgcolor="#FFE4E1">

    <td><?php system("uptime"); ?></td>

  </tr>

  <tr bgcolor="#000000">

    <td><font color="#FFFFFF"><b>System Information:</b></font></td>

  </tr>

  <tr bgcolor="#FFDAB9">

    <td><?php system("uname -a"); ?></td>

  </tr>

 <tr bgcolor="#000000">

    <td><font color="#FFFFFF"><b>Memory Usage (MB):</b></font></td>

  </tr>

  <tr bgcolor="#FFF0F5">

    <td><?php system("free -m"); ?></td>

  </tr>

 <tr bgcolor="#000000">

    <td><font color="#FFFFFF"><b>Disk Usage:</b></font></td>

  </tr>

  <tr bgcolor="#E6E6FA">

    <td><?php system("df -h"); ?></td>

  </tr>

 <tr bgcolor="#000000">

    <td><font color="#FFFFFF"><b>CPU Information:</b></font></td>

  </tr>

  <tr bgcolor="#F0FFF0">

    <td><?php system("cat /proc/cpuinfo | grep \"model name\\|processor\""); ?></td>

  </tr>

</table>