The Execution Operator | Spring Into PHP 5

Here's a cool onethe execution operator lets you run operating system commands and programs. All you've got to do is to enclose the command you want to run in backticks (`not the same as a single quote!). Here's an example that runs the date system command, captures the output, and displays it:

 <?php $output =  `date`; echo $output; ?>

Here's the kind of result you might see under Unix, using the bash shell:

 -bash-2.05b$ php t.php Thu Aug 12 10:53:28 PDT 2004

Because date is also a command in DOS, here's what you might see in a DOS window:

 C:\php>php t.php The current date is: Thu 08/12/2004 Enter the new date: (mm-dd-yy)

What if you want to pass an argument to the system command? Include the argument in the backticks too, as in the following, where we're executing the command dir c:\temp in Windows:

 <?php     $output = `dir c:\\temp`;     echo $output; ?>

The result appears in Figure 2-4.

Figure 2-4. Executing system commands.