Carrying the Load - PHP

Linux file structure contains within it a special area called /proc. Now, some believe that there's black magic in that directory. For those who know better than to fear the /proc, there awaits much good magic, in the form of server info. Looking for a way to retrieve real-time server information and display it to users in your Web application? Today's your lucky day! Take a look at the patSysinfo PHP class, which lets you do that and a whole lot more.

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By: icarus, (c) Melonfire

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February 16, 2004

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If it's system performance you're interested in, patSysinfo can give you that as well. Consider the getLoadAvg() method, which returns the average CPU load for the last 1, 5 and 15 minutes, or the getNumberUsers() function, which returns the number of users currently logged in to the system.

<?php // include class include("patSysinfo.php"); // instantiate object $sys = new patSysinfo(); // get load average // returns array of 3 values $loadArray = $sys->getLoadAvg(); // get number of users $users = $sys->getNumberUser(); // output values echo "Load averages " . $loadArray[0] . " (1 min) " . $loadArray[1] . " (5 min) " . $loadArray[2] . " (15 min), $users users"; ? >

Here's the output:

Load averages 0.01 (1 min) 2.11 (5 min) 1.43 (15 min), 12 users

You can obtain a list of all running processes with the getProcesses() method, equivalent to the UNIX "ps" command. The list of processes is returned as an array, each element of which represents a running process and contains details on that process' owner, ID, current status and resource usage. Consider the following example, which illustrates:

<html> <head> </head> <body> <table border="1" cellspacing="0" cellpadding="5"> <tr> <td>Process ID</td> <td>Command</td> <td>Owner</td> <td>Terminal</td> <td>Status</td> <td>Start</td> <td>Duration</td> <td>CPU %</td> <td>Memory %</td> </tr> <?php // include class include("patSysinfo.php"); // instantiate object $sys = new patSysinfo(); // get process list $processes = $sys->getProcesses(); foreach ($processes as $p) { echo "<tr>"; echo "<td>" . $p[pid] . "</td>"; echo "<td>" . $p[command] . "</td>"; echo "<td>" . $p[user] . "</td>"; echo "<td>" . $p[tty] . "</td>"; echo "<td>" . $p[stat] . "</td>"; echo "<td>" . $p[start] . "</td>"; echo "<td>" . $p[time] . "</td>"; echo "<td>" . $p[cpu] . "</td>"; echo "<td>" . $p[mem] . "</td>"; echo "</tr>"; } ? > </table> </body> </html>

And here's what the output looks like:

patSysinfo

A variant of this is the getTopProcesses() method, which returns the same output as getProcesses() but sorts the data by CPU usage. Here's the script,

<html> <head> </head> <body> <table border="1" cellspacing="0" cellpadding="5"> <tr> <td>Process ID</td> <td>Command</td> <td>Owner</td> <td>Terminal</td> <td>Status</td> <td>Start</td> <td>Duration</td> <td>CPU %</td> <td>Memory %</td> </tr> <?php // include class include("patSysinfo.php"); // instantiate object $sys = new patSysinfo(); // get process list $processes = $sys->getTopProcesses(); foreach ($processes as $p) { echo "<tr>"; echo "<td>" . $p['pid'] . "</td>"; echo "<td>" . $p['command'] . "</td>"; echo "<td>" . $p['user'] . "</td>"; echo "<td>" . $p['tty'] . "</td>"; echo "<td>" . $p['stat'] . "</td>"; echo "<td>" . $p['start'] . "</td>"; echo "<td>" . $p['time'] . "</td>"; echo "<td>" . $p['cpu'] . "</td>"; echo "<td>" . $p['mem'] . "</td>"; echo "</tr>"; } ? > </table> </body> </html>

and here's the output:

patSysinfo

For script such as these, which retrieve real-time information from the system, it's a good idea to insert an auto-refresh header at the top of the page, so that the page automatically updates itself with the latest information at a user-specified interval.

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