dolibarr/htdocs/includes/escpos/example/interface/linux-usb.php

<?php
/* Change to the correct path if you copy this example! */
require_once(dirname(__FILE__) . "/../../Escpos.php");

/**
 * On Linux, use the usblp module to make your printer available as a device
 * file. This is generally the default behaviour if you don't install any
 * vendor drivers.
 *
 * Once this is done, use a FilePrintConnector to open the device.
 *
 * Troubleshooting: On Debian, you must be in the lp group to access this file.
 * dmesg to see what happens when you plug in your printer to make sure no
 * other drivers are unloading the module.
 */
try {
	// Enter the device file for your USB printer here
	$connector = null;
	//$connector = new FilePrintConnector("/dev/usb/lp0");
	//$connector = new FilePrintConnector("/dev/usb/lp1");
	//$connector = new FilePrintConnector("/dev/usb/lp2");

	/* Print a "Hello world" receipt" */
	$printer = new Escpos($connector);
	$printer -> text("Hello World!\n");
	$printer -> cut();
	
	/* Close printer */
	$printer -> close();
} catch(Exception $e) {
	echo "Couldn't print to this printer: " . $e -> getMessage() . "\n";
}