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Running Commands with exec()

The exec() function is one of several functions you can use to pass commands to the shell. The exec() function requires a string representing the path to the command you want to run, and optionally accepts an array variable which will contain the output of the command, and a scalar variable which will contain the return value (1 or 0). For example:

exec("/path/to/somecommand", $output_array, $return_val);

Listing 12.4 uses the exec() function to produce a directory listing with the shell-based ls command.

Listing 12.4. Using exec() and ls to Produce a Directory Listing

1: <?php 2: exec("ls -al .", $output_array, $return_val); 3: echo "Returned $return_val<br>"; 4: foreach ($output_array as $o) { 5: echo "$o <br>"; ...