gnu/io/RXTXCommDriver.java

/*-------------------------------------------------------------------------
|   RXTX License v 2.1 - LGPL v 2.1 + Linking Over Controlled Interface.
|   RXTX is a native interface to serial ports in java.
|   Copyright 1998 Kevin Hester, kevinh@acm.org
|   Copyright 2000-2008 Trent Jarvi tjarvi@qbang.org and others who
|   actually wrote it.  See individual source files for more information.
|
|   A copy of the LGPL v 2.1 may be found at
|   http://www.gnu.org/licenses/lgpl.txt on March 4th 2007.  A copy is
|   here for your convenience.
|
|   This library is free software; you can redistribute it and/or
|   modify it under the terms of the GNU Lesser General Public
|   License as published by the Free Software Foundation; either
|   version 2.1 of the License, or (at your option) any later version.
|
|   This library is distributed in the hope that it will be useful,
|   but WITHOUT ANY WARRANTY; without even the implied warranty of
|   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
|   Lesser General Public License for more details.
|
|   An executable that contains no derivative of any portion of RXTX, but
|   is designed to work with RXTX by being dynamically linked with it,
|   is considered a "work that uses the Library" subject to the terms and
|   conditions of the GNU Lesser General Public License.
|
|   The following has been added to the RXTX License to remove
|   any confusion about linking to RXTX.   We want to allow in part what
|   section 5, paragraph 2 of the LGPL does not permit in the special
|   case of linking over a controlled interface.  The intent is to add a
|   Java Specification Request or standards body defined interface in the
|   future as another exception but one is not currently available.
|
|   http://www.fsf.org/licenses/gpl-faq.html#LinkingOverControlledInterface
|
|   As a special exception, the copyright holders of RXTX give you
|   permission to link RXTX with independent modules that communicate with
|   RXTX solely through the Sun Microsytems CommAPI interface version 2,
|   regardless of the license terms of these independent modules, and to copy
|   and distribute the resulting combined work under terms of your choice,
|   provided that every copy of the combined work is accompanied by a complete
|   copy of the source code of RXTX (the version of RXTX used to produce the
|   combined work), being distributed under the terms of the GNU Lesser General
|   Public License plus this exception.  An independent module is a
|   module which is not derived from or based on RXTX.
|
|   Note that people who make modified versions of RXTX are not obligated
|   to grant this special exception for their modified versions; it is
|   their choice whether to do so.  The GNU Lesser General Public License
|   gives permission to release a modified version without this exception; this
|   exception also makes it possible to release a modified version which
|   carries forward this exception.
|
|   You should have received a copy of the GNU Lesser General Public
|   License along with this library; if not, write to the Free
|   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
|   All trademarks belong to their respective owners.
--------------------------------------------------------------------------*/
/**
*
*	Martin Pool <mbp@linuxcare.com> added support for
* 	explicitly-specified lists of ports, October 2000.
*
* 	Joseph Goldstone <joseph@lp.com> reorganized to support registered
* 	ports, known ports, and scanned ports, July 2001.
*
**/

package gnu.io;

import java.lang.*;
import java.util.*;
import java.io.*;
import java.util.StringTokenizer;

/**
*   This is the JavaComm for Linux driver.
*/

public class RXTXCommDriver implements CommDriver
{

	private final static boolean debug = "true".equals( System.getProperty( "gnu.io.rxtx.DEBUG" ) );
	private final static boolean CheckLPT = "true".equals( System.getProperty( "gnu.io.rxtx.CheckL" ) );
	private final static boolean noVersionOutput = "true".equals( System.getProperty( "gnu.io.rxtx.NoVersionOutput" ) );


	static
	{
		if(debug) System.out.println("RXTXCommDriver{}:Static");
		System.loadLibrary( "rxtxSerial" );

		/**
		*	Perform a crude check to make sure people don't mix
		*	versions of the Jar and native lib
		*
		*	Mixing the libs can create a nightmare.
		*
		*	It could be possible to move this over to RXTXVersion
		*	but All we want to do is warn people when first loading
		*	the Library.
		**/

		String JarVersion = RXTXVersion.getVersion();
		String LibVersion;

		try
		{
			LibVersion = RXTXVersion.nativeGetVersion();
		}
		catch ( Error UnsatisfiedLinkError )
		{

			/**
			*	for rxtx prior to 2.1.7
			**/

			LibVersion = nativeGetVersion();
		}
		if (!debug)
		{
			if ( ! noVersionOutput )
			{
				System.out.println(" RXTX Comm  - Stable Library");
				System.out.println(" =================================");
				System.out.println(" Native lib Version = " + LibVersion);
				System.out.println(" Java lib Version   = " + JarVersion);
			}

		}
		else
		{
			System.out.println(" ==================================");
			System.out.println(" =                                =");
			System.out.println(" = RXTX Comm - In Java DEBUG mode =");
			System.out.println(" =                                =");
			System.out.println(" ==================================");

		}

		if ( ! JarVersion.equals( LibVersion ) )
		{
			System.out.println(" WARNING:  RXTX Version mismatch");
			System.out.println(" ** Jar version = " + JarVersion);
			System.out.println(" ** Native lib Version = " + LibVersion);
		}
		else if (debug)
		{
			System.out.println(" ** Jar version = " + JarVersion);
			System.out.println(" ** Native lib Version = " + LibVersion);
		}

		if(debug) System.out.println("RXTXCommDriver{}:Static:Exit");

	}

	/**
	*	Get the Serial port prefixes for the running OS
	**/

	private String deviceDirectory;
	private String osName;
	private native boolean registerKnownPorts(int PortType);
	private native boolean isPortPrefixValid(String dev);
	private native boolean testRead(String dev, int type);
	private native String getDeviceDirectory();

	/**
	*	for rxtx prior to 2.1.7
	**/

	public static native String nativeGetVersion();

	private final String[] getValidPortPrefixes(
		String CandidatePortPrefixes[]
	)
	{
		/**
		*  	256 is the number of prefixes ( COM, cua, ttyS, ...) not
		*	the number of devices (ttyS0, ttyS1, ttyS2, ...)
		*
		*	On a Linux system there are about 400 prefixes in
		*	deviceDirectory.
		*	registerScannedPorts() assigns CandidatePortPrefixes to
		*	something less than 50 prefixes.
		*
		*	Trent
		**/

		String ValidPortPrefixes[]=new String [256];

		if (debug) System.out.println("RXTXCommDriver:getValidPortPrefixes()");

		if(CandidatePortPrefixes==null)
		{
			if (debug)
			{
				System.out.println(" No ports prefixes known for this System.");
				System.out.println(" Please check the port prefixes listed");
				System.out.println(" for " + osName + " in registerScannedPorts()");
			}
		}

		int i=0;
		for(int j=0;j<CandidatePortPrefixes.length;j++)
		{
			if(isPortPrefixValid(CandidatePortPrefixes[j])) {
				ValidPortPrefixes[i++]= CandidatePortPrefixes[j];
			}
		}

		String[] returnArray=new String[i];
		System.arraycopy(ValidPortPrefixes, 0, returnArray, 0, i);

		if(ValidPortPrefixes[0]==null)
		{
			if (debug)
			{
				System.out.println(" No ports matched the list assumed for this");
				System.out.println(" System in the directory " + deviceDirectory);
				System.out.println(" Please check the ports listed for");
				System.out.println(" \"" + osName + "\" in");
				System.out.println(" RXTXCommDriver:registerScannedPorts()");
				System.out.println(" Tried:");
				for(int j=0;j<CandidatePortPrefixes.length;j++){
					System.out.println(" - " + CandidatePortPrefixes[i]);
				}
			}
		}
		else
		{
			if (debug)
			{
				System.out.println(" The following port prefixes have been");
				System.out.println(" identified as valid on " + osName + ":");
				System.out.println(" -- ouput withheld --");

				/**
				*	for(int j=0;j<returnArray.length;j++)
				*	{
				*	if (debug) System.out.println("\t" + j + " " + returnArray[j]);
				*	}
				**/
			}
		}
		if (debug) System.out.println("RXTXCommDriver:getValidPortPrefixes:Exit");

		return returnArray;


	}

	/**
	*	handle solaris/sunos /dev/cua/a convention
	**/

	private void checkSolaris(
		String PortName,
		int PortType
	)
	{
		System.out.println("RXTXCommDriver:checkSolaris()");

		char p[] =  { 91 };

		for( p[0] =97 ;p[0] < 123; p[0]++ )
		{
			if (testRead(PortName.concat(new String(p)),PortType))
			{
				CommPortIdentifier.addPortName(
					PortName.concat(new String(p)),
					PortType,
					this
				);
			}
		}

		/**
		*	check for 0-9 in case we have them (Solaris USB)
		**/

		for( p[0] =48 ;p[0] <= 57; p[0]++ )
		{
			if (testRead(PortName.concat(new String(p)),PortType))
			{
				CommPortIdentifier.addPortName(
						PortName.concat(new String(p)),
						PortType,
						this
				);
			}
		}

		if (debug) System.out.println("RXTXCommDriver:checkSolaris:Exit");
	}

	private void registerValidPorts(
		String CandidateDeviceNames[],
		String ValidPortPrefixes[],
		int PortType
	)
	{
		if (debug) System.out.println("RXTXCommDriver:registerValidPorts(" + PortType + ")");

		int i =0;
		int p =0;

		/**
		*	FIXME quick fix to get COM1-8 on windows working.  The
		*	Read test is not working properly and its crunch time...
		*	if(osName.toLowerCase().indexOf("windows") != -1 )
		*	{
		*		for( i=0;i < CandidateDeviceNames.length;i++ )
		*		{
		*			CommPortIdentifier.addPortName(
		*				CandidateDeviceNames[i],
		*				PortType,
		*				this
		*			);
		*		}
		*		return;
		*
		*	}
		**/

		if (debug)
		{

			System.out.println(" Candidate Ports");
			for (
				int dn=0;
				dn<CandidateDeviceNames.length;
				dn++
			)
			{
				System.out.println(" - " + CandidateDeviceNames[dn]);
			}
			System.out.println(" Valid port prefixes:");
			for (
				int pp=0;
				pp<ValidPortPrefixes.length;
				pp++
			)
			{
				System.out.println(" - " + ValidPortPrefixes[pp]);
			}
		}

		if ( CandidateDeviceNames!=null && ValidPortPrefixes!=null)
		{
			for( i = 0;i<CandidateDeviceNames.length; i++ )
			{
				for( p = 0;p<ValidPortPrefixes.length; p++ )
				{
					/**
					*	this determines:
					* 	device file Valid ports
					* 	/dev/ttyR[0-9]*  != /dev/ttyS[0-9]*
					* 	/dev/ttySI[0-9]* != /dev/ttyS[0-9]*
					* 	/dev/ttyS[0-9]*  == /dev/ttyS[0-9]*
					*
					*	Otherwise we check some ports
					*	multiple times.  Perl would rock
					*	here.
					*
					*	If the above passes, we try to read
					*	from the port.  If there is no err
					*	the port is added.
					*
					*	Trent
					**/

					String V =  ValidPortPrefixes[ p ];
					String C =   CandidateDeviceNames[ i ];

					int VL = V.length();

					if( C.length() < VL ) continue;

					String CU =	C.substring(VL).toUpperCase();
					String Cl =	C.substring(VL).toLowerCase();

					if
					(
						!(
							C.regionMatches(0, V, 0, VL ) &&
							CU.equals( Cl )
						)
					)
					{
						continue;
					}

					String PortName;

					if(osName.toLowerCase().indexOf("windows") == -1 )
					{
						PortName = deviceDirectory + C;
					}
					else
					{
						PortName = C;
					}

					if (debug)
					{
						System.out.println( " - " + C + " " + V );
						System.out.println( " - " + CU + " " + Cl );
					}

					if
					(
						osName.equals("Solaris") ||
						osName.equals("SunOS"))
						checkSolaris(PortName,PortType);
					else
					{
						if (debug) System.out.println(" CheckLPT is " + CheckLPT + " and PortType is" + PortType);
						if ( (!CheckLPT) && (PortType!=1) )
						{
							/**
							*	Don't attempt to check LPT ports,
							*	if CheckLPT is set to false in env args
							**/

							CommPortIdentifier.addPortName
							(
								PortName,
								PortType,
								this
							);
						}
						else
						{
							if (testRead(PortName, PortType))
							{
								CommPortIdentifier.addPortName
								(
									PortName,
									PortType,
									this
								);
							}
						}

					}
				}
			}
		}

		if (debug) System.out.println("RXTXCommDriver:registerValidPorts:Exit");

	}


	/**
	*	initialize() will be called by the CommPortIdentifier's static
*	initializer. The responsibility of this method is:
*	1) Ensure that that the hardware is present.
*	2) Load any required native libraries.
*	3) Register the port names with the CommPortIdentifier.
	*
	*	<p>From the NullDriver.java CommAPI sample.
	*	added printerport stuff
	*	Holger Lehmann
	*	July 12, 1999
	*	IBM
	*
	* 	Added ttyM for Moxa boards
	* 	Removed obsolete device cuaa
	* 	Peter Bennett
	* 	January 02, 2000
	* 	Bencom
**/

	/**
	*	Determine the OS and where the OS has the devices located
	**/
	public void initialize()
	{

		if (debug) System.out.println("RXTXCommDriver:initialize()");

		osName=System.getProperty("os.name");
		deviceDirectory=getDeviceDirectory();

		/**
		*	First try to register ports specified in the properties
		*	file.  If that doesn't exist, then scan for ports.
		**/

		for
		(
			int PortType=CommPortIdentifier.PORT_SERIAL;
			PortType<=CommPortIdentifier.PORT_PARALLEL;
			PortType++
		)
		{
			/**
			*	Load prefixes for all ports from env and file pairs
			**/
			if (!registerSpecifiedPorts(PortType))
			{

				/**
				*	Load OS knoow ports (APPLE thing)
				**/
				if (!registerKnownPorts(PortType))
				{

					/**
					*	Load ports via a scan...
					**/
					registerScannedPorts(PortType);
				}
			}
		}

		if (debug) System.out.println("RXTXCommDriver:initialize:Exit");

	}

	private void addSpecifiedPorts(
		String names,
		int PortType
	)
	{

		if (debug) System.out.println("RXTXCommDriver:addSpecifiedPorts()");

		final String pathSep = System.getProperty("path.separator", ":");
		final StringTokenizer tok = new StringTokenizer(names, pathSep);

		while (tok.hasMoreElements())
		{
			String PortName = tok.nextToken();

			if (testRead(PortName, PortType))
				CommPortIdentifier.addPortName(PortName,
					PortType, this);
		}

		if (debug) System.out.println("RXTXCommDriver:addSpecifiedPorts:Exit");

	}

	/**
*	Register ports specified in the file "gnu.io.rxtx.properties"
*	Key system properties:
*	gnu.io.rxtx.SerialPorts
*	gnu.io.rxtx.ParallelPorts
*
*	Tested only with sun jdk1.3
*
*	The file gnu.io.rxtx.properties must reside in the java extension dir
*
*	Example: /usr/local/java/jre/lib/ext/gnu.io.rxtx.properties
*
*	The file contains the following key properties:
*
*  	gnu.io.rxtx.SerialPorts=/dev/ttyS0:/dev/ttyS1:
*  	gnu.io.rxtx.ParallelPorts=/dev/lp0:
*
**/
	private boolean registerSpecifiedPorts(
		int PortType
	)
	{
		if (debug) System.out.println("RXTXCommDriver:registerSpecifiedPorts(" + PortType + ")");

		final String pathSep = System.getProperty("path.separator", ":");
		final String fileSep = System.getProperty("file.separator");
		String val = null;
		String err_str = null;
		String ext_loc[];
		boolean props_loaded = false;

		/**
		*	Save System properties, to restore on func exit.
		**/

		Properties origp = System.getProperties();

		String ext_dir=System.getProperty("java.ext.dirs");

		if (ext_dir.length() > 0)
		{

			if (ext_dir.indexOf(":") > 0)
			{
				ext_loc = ext_dir.split(pathSep);
			}
			else
			{
				ext_loc = new String[1];
				ext_loc[1] = ext_dir;

			}

			for (
				int el=0;
				el<ext_loc.length;
				el++
			)
			{
				ext_loc[el] = ext_loc[el] + fileSep;

				if (debug)
					System.out.println(" - searching config location " + ext_loc[el]);

				try
				{
					FileInputStream rxtx_prop=new FileInputStream(ext_loc[el] + "gnu.io.rxtx.properties");
					Properties p=new Properties();
					p.load(rxtx_prop);
					System.setProperties(p);
					for (Iterator it = p.keySet().iterator(); it.hasNext();)
					{
						String key = (String) it.next();
						System.setProperty(key, p.getProperty(key));
					}
				}
				catch(Exception e)
				{
					err_str = e.toString();

					if (debug)
					{
						if (err_str.indexOf("java.io.FileNotFoundException") < 0)
						{
							System.out.println(err_str);
						}
						else
						{
							System.out.println("   -> The file '" + ext_loc[el] + "gnu.io.rxtx.properties' doesn't exists.");
						}
					}
				}
			}
		}
		if (debug)
			System.out.println(" Checking Environment Properties for ports of type " + PortType);

		switch (PortType) {
			case CommPortIdentifier.PORT_SERIAL:
				if ((val = System.getProperty("gnu.io.rxtx.SerialPorts")) == null)
				{
					val = System.getProperty("gnu.io.SerialPorts");
					if (debug)
						System.out.println(" - Capture gnu.io.SerialPorts = '" + val + "' where Port Type =" + PortType);
				}
				break;

			case CommPortIdentifier.PORT_PARALLEL:
				if ((val = System.getProperty("gnu.io.rxtx.ParallelPorts")) == null)
				{
					val = System.getProperty("gnu.io.ParallelPorts");
					if (debug)
						System.out.println(" - Capture gnu.io.ParallelPorts = '" + val + "' where Port Type =" + PortType);
				}
				break;
			default:
				if (debug)
				System.out.println(" !!ERROR - Unknown port type " + PortType + " passed to RXTXCommDriver.registerSpecifiedPorts()");
		}

		/**
		*	Not sure if the following line undoes the properties load,
		*	or just ensures properties before the proc is called are
		*	not manipulated.  Anti-injection?  - We've finished with
		*	them anyway...
		**/
		System.setProperties(origp); //recall saved properties

		if (val != null)
		{

			addSpecifiedPorts(val, PortType);
			if (debug)
			{
				System.out.println(" = Ports added from Environmental Properties");
				System.out.println("RXTXCommDriver:registerSpecifiedPorts(True):Exit");
			}
			return true;
		}
		else
		{
			if (debug) System.out.println("RXTXCommDriver:registerSpecifiedPorts(False):Exit");
			return false;
		}
	}

	/**
	*	Look for all entries in deviceDirectory, and if they look like they should
	*	be serial ports on this OS and they can be opened then register
	*	them.
	**/

	private void registerScannedPorts(
		int PortType
	)
	{
		if (debug) System.out.println("RXTXCommDriver:registerScannedPorts(" + PortType + ")");

		String[] 	CandidateDeviceNames;
		int 		iFound;

		if (debug) System.out.println(" Scanning " + deviceDirectory + " for ports of type " + PortType);

		if(osName.equals("Windows CE"))
		{
			String[] temp = {
				"COM1:",
				"COM2:",
				"COM3:",
				"COM4:",
				"COM5:",
				"COM6:",
				"COM7:",
				"COM8:"
			};
			CandidateDeviceNames=temp;
		}
		else if(osName.toLowerCase().indexOf("windows") != -1 )
		{
			String[] temp = new String[259];
			for( int i = 1; i <= 256; i++ )
			{
				temp[i - 1] = "COM" + i;
			}
			for( int i = 1; i <= 3; i++ )
			{
				temp[i + 255] = "LPT" + i;
			}
			CandidateDeviceNames=temp;
		}
		else if ( osName.equals("Solaris") || osName.equals("SunOS"))
		{
			/**
			*	Solaris uses a few different ways to identify ports.
			*	They could be /dev/term/a /dev/term0 /dev/cua/a /dev/cuaa
			*	the /dev/???/a appears to be on more systems.
			*
			*	The uucp lock files should not cause problems.
			*/

			/**
			*	File dev = new File( "/dev/term" );
			*	String deva[] = dev.list();
			*	dev = new File( "/dev/cua" );
			*	String devb[] = dev.list();
			*	String[] temp = new String[ deva.length + devb.length ];
			*	for(int j =0;j<deva.length;j++)
			*		deva[j] = "term/" + deva[j];
			*	for(int j =0;j<devb.length;j++)
			*		devb[j] = "cua/" + devb[j];
			*	System.arraycopy( deva, 0, temp, 0, deva.length );
			*	System.arraycopy( devb, 0, temp,
			*			deva.length, devb.length );
			*	if( debug ) {
			*		for( int j = 0; j< temp.length;j++)
			*			System.out.println( temp[j] );
			*	}
			*	CandidateDeviceNames=temp;
			**/

			/**
			*	ok..  Look the the dirctories representing the port
			*	kernel driver interface.
			*
			*	If there are entries there are possibly ports we can
			*	use and need to enumerate.
			**/

			String term[] = new String[2];
			int l = 0;
			File dev = null;
			dev = new File( "/dev/term" );
			if( dev.list().length > 0 ) term[l++] ="term/";

			/**
			*	dev = new File( "/dev/cua0" );
			*	if( dev.list().length > 0 ) term[l++] = "cua/";
			**/

			String[] temp = new String[l];
			for(l--;l >= 0;l--) temp[l] = term[l];
			CandidateDeviceNames=temp;
		}
		else
		{
			File dev = new File( deviceDirectory );
			String[] temp = dev.list();
			CandidateDeviceNames=temp;
		}

		if (CandidateDeviceNames==null)
		{
				if (debug) System.out.println(" No device files to check ");
				return;
		}
		else
		{
			int found = CandidateDeviceNames.length;
			if (debug) System.out.println(" Found " + found + " devices files to check");
		}

		String CandidatePortPrefixes[] = {};

		switch (PortType) {
			case CommPortIdentifier.PORT_SERIAL:
				if (debug) System.out.println(" scanning for serial ports for os " + osName);

				/**
				*	There are _many_ possible ports that can be used
				*	on Linux.  See below in the fake Linux-all-ports
				*	case for a list.  You may add additional ports
				*	here but be warned that too many will significantly
				*	slow down port enumeration.  Linux 2.6 has udev
				*	support which should be faster as only ports the
				*	kernel finds should be exposed in /dev
				*
				*	See also how to override port enumeration and
				*	specifying port in INSTALL.
				*
				*	taj
				**/

				if(osName.equals("Linux"))
				{
					String[] Temp = {
					"ttyS",		// linux Serial Ports
					"ttySA",	// for the IPAQs
					"ttyUSB",	// for USB frobs
					"rfcomm",   // bluetooth serial device
					"ttyircomm"	// linux IrCommdevices (IrDA serial emu)
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("Linux-all-ports"))
				{
					/**
					*	If you want to enumerate all ports ~5000
					*	possible, then replace the above with this
					**/

					String[] Temp = {
						"comx",  // linux COMMX synchronous serial card
						"holter",// custom card for heart monitoring
						"modem", // linux symbolic link to modem.
						"rfcomm",   // bluetooth serial device
						"ttyircomm",	// linux IrCommdevices (IrDA serial emu)
						"ttycosa0c",	// linux COSA/SRP synchronous serial card
						"ttycosa1c",	// linux COSA/SRP synchronous serial card
						"ttyACM",		// linux CDC ACM devices
						"ttyC",			// linux cyclades cards
						"ttyCH",		// linux Chase Research AT/PCI-Fast serial card
						"ttyD",			// linux Digiboard serial card
						"ttyE",			// linux Stallion serial card
						"ttyF",			// linux Computone IntelliPort serial card
						"ttyH",			// linux Chase serial card
						"ttyI",			// linux virtual modems
						"ttyL",			// linux SDL RISCom serial card
						"ttyM",			// linux PAM Software's multimodem boards
						"ttyMX",		// linux Moxa Smart IO cards
						"ttyP",			// linux Hayes ESP serial card
						"ttyR",			// linux comtrol cards
						"ttyS",			// linux Serial Ports
						"ttySI",		// linux SmartIO serial card
						"ttySR",		// linux Specialix RIO serial card 257+
						"ttyT",			// linux Technology Concepts serial card
						"ttyUSB",		//linux USB serial converters
						"ttyV",			// linux Comtrol VS-1000 serial controller
						"ttyW",			// linux specialix cards
						"ttyX"			// linux SpecialX serial card
					};

					CandidatePortPrefixes=Temp;
				}
				else if(osName.toLowerCase().indexOf("qnx") != -1 )
				{
					String[] Temp = {
						"ser"
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("Irix"))
				{
					String[] Temp = {
						"ttyc",	// irix raw character devices
						"ttyd", // irix basic serial ports
						"ttyf", // irix serial ports with hardware flow
						"ttym", // irix modems
						"ttyq", // irix pseudo ttys
						"tty4d",// irix RS422
						"tty4f",// irix RS422 with HSKo/HSki
						"midi", // irix serial midi
						"us"	// irix mapped interface
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("FreeBSD"))
				//See here: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/serial.html
				{
					String[] Temp = {
						"ttyu",	//general purpose serial ports
						"ttyU",	//general purpose serial ports (UArduino Drv)
						"cuau",	//general purpose serial ports (post v10)
						"cuaU",	//general purpose serial ports (UARduino Drv)
						"cuad",	//general purpose serial ports (pre v10)
						"ttyd",	//general purpose serial ports

						//Historic <v8 - Not sure if drvs still work?
						"cuaa",	//dialout serial ports
						"ttyA",	//Specialix SI/XIO dialin ports
						"cuaA",	//Specialix SI/XIO dialout ports
						"ttyD",	//Digiboard - 16 dialin ports
						"cuaD",	//Digiboard - 16 dialout ports
						"ttyE",	//Stallion EasyIO (stl) dialin ports
						"cuaE",	//Stallion EasyIO (stl) dialout ports
						"ttyF",	//Stallion Brumby (stli) dialin ports
						"cuaF",	//Stallion Brumby (stli) dialout ports
						"ttyR",	//Rocketport dialin ports
						"cuaR",	//Rocketport dialout ports
						"stl"	//Stallion EasyIO board or Brumby N
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("NetBSD")) // FIXME this is probably wrong
				{
					String[] Temp = {
						"tty0"	// netbsd serial ports
					};
					CandidatePortPrefixes=Temp;
				}
				else if ( osName.equals("Solaris") || osName.equals("SunOS"))
				{
					String[] Temp = {
						"term/",
						"cua/"
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("HP-UX"))
				{
					String[] Temp = {
						"tty0p",	// HP-UX serial ports
						"tty1p"		// HP-UX serial ports
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("UnixWare") || osName.equals("OpenUNIX"))
				{
					String[] Temp = {
						"tty00s",	// UW7/OU8 serial ports
						"tty01s",
						"tty02s",
						"tty03s"
					};
					CandidatePortPrefixes=Temp;
				}
				else if	(osName.equals("OpenServer"))
				{
					String[] Temp = {
						"tty1A",	// OSR5 serial ports
						"tty2A",
						"tty3A",
						"tty4A",
						"tty5A",
						"tty6A",
						"tty7A",
						"tty8A",
						"tty9A",
						"tty10A",
						"tty11A",
						"tty12A",
						"tty13A",
						"tty14A",
						"tty15A",
						"tty16A",
						"ttyu1A",	// OSR5 USB-serial ports
						"ttyu2A",
						"ttyu3A",
						"ttyu4A",
						"ttyu5A",
						"ttyu6A",
						"ttyu7A",
						"ttyu8A",
						"ttyu9A",
						"ttyu10A",
						"ttyu11A",
						"ttyu12A",
						"ttyu13A",
						"ttyu14A",
						"ttyu15A",
						"ttyu16A"
					};
					CandidatePortPrefixes=Temp;
				}
				else if (osName.equals("Compaq's Digital UNIX") || osName.equals("OSF1"))
				{
					String[] Temp = {
						"tty0"	// Digital Unix serial ports
					};
					CandidatePortPrefixes=Temp;
				}
					else if(osName.equals("BeOS"))
				{
					String[] Temp = {
						"serial"	// BeOS serial ports
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.equals("Mac OS X"))
				{
					String[] Temp = {
						"cu.KeyUSA28X191.",		// Keyspan USA-28X adapter, USB port 1
						"tty.KeyUSA28X191.",	// Keyspan USA-28X adapter, USB port 1
						"cu.KeyUSA28X181.", 	// Keyspan USA-28X adapter, USB port 2
						"tty.KeyUSA28X181.", 	// Keyspan USA-28X adapter, USB port 2
						"cu.KeyUSA19181.", 		// Keyspan USA-19 adapter
						"tty.KeyUSA19181." 		// Keyspan USA-19 adapter
					};
					CandidatePortPrefixes=Temp;
				}
				else if(osName.toLowerCase().indexOf("windows") != -1 )
				{
					String[] Temp = {
						"COM"		// win32 serial ports
						//"//./COM"	// win32 serial ports (piped)
					};
					CandidatePortPrefixes=Temp;
				}
				else
				{
					if (debug) System.out.println("No valid prefixes for serial ports have been entered for "+osName + " in RXTXCommDriver.java.  This may just be a typo in the method registerScanPorts().");
				}

				iFound = CandidateDeviceNames.length;
				if (debug) System.out.println("Found " + iFound + " port prefixes on " + osName + " for port type " + PortType);
				break;

			case CommPortIdentifier.PORT_PARALLEL:

				if (debug) System.out.println("scanning for parallel ports for os "+osName);

				/**
				*	Get the Parallel port prefixes for the running os
				*	Holger Lehmann
				*	July 12, 1999
				*	IBM
				**/

				if(osName.equals("Linux")

				/**
				*	|| osName.equals("NetBSD") FIXME
				*	|| osName.equals("HP-UX")  FIXME
				*	|| osName.equals("Irix")   FIXME
				*	|| osName.equals("BeOS")   FIXME
				*	|| osName.equals("Compaq's Digital UNIX")   FIXME
				**/

				)
				{
					String[] temp={
						"lp"	// linux printer port
					};
					CandidatePortPrefixes=temp;
				}
				else if(osName.equals("FreeBSD"))
				{
					String[] temp={
						"lpt"
					};
					CandidatePortPrefixes=temp;
				}
				else if(osName.toLowerCase().indexOf("windows") != -1 )
				{
					String[] temp={
						"LPT"
					};
					CandidatePortPrefixes=temp;
				}
				else  /* printer support is green */
				{
					String [] temp={};
					CandidatePortPrefixes=temp;
				}

				iFound = CandidateDeviceNames.length;
				if (debug) System.out.println("Found " + iFound + " port prefixes on " + osName + " for port type " + PortType);

				break;

			default:
				if (debug) System.out.println(" Unknown PortType " + PortType + " passed to RXTXCommDriver.registerScannedPorts()");
		}

		registerValidPorts(
			CandidateDeviceNames,
			CandidatePortPrefixes,
			PortType
		);

		if (debug) System.out.println("RXTXCommDriver:registerScannedPorts:Exit");

	}


	/**
	* <p>From the NullDriver.java CommAPI sample.
	*
	*	@param PortName The name of the port the OS recognizes
	*	@param PortType CommPortIdentifier.PORT_SERIAL or PORT_PARALLEL
	*	@return CommPort
	*	getCommPort() will be called by CommPortIdentifier from its
	*	openPort() method. PortName is a string that was registered earlier
	*	using the CommPortIdentifier.addPortName() method. getCommPort()
	*	returns an object that extends either SerialPort or ParallelPort.
	**/

	public CommPort getCommPort(
		String PortName,
		int PortType
	)
	{
		if (debug) System.out.println("RXTXCommDriver:getCommPort(" + PortName + "," + PortType + ")");
		try
		{
			switch (PortType) {
				case CommPortIdentifier.PORT_SERIAL:
					if(osName.toLowerCase().indexOf("windows") == -1 )
					{
						return new RXTXPort( PortName );
					}
					else
					{
						return new RXTXPort( deviceDirectory + PortName );
					}
				case CommPortIdentifier.PORT_PARALLEL:
					return new LPRPort( PortName );
				default:
					if (debug)
						System.out.println(" Unknown PortType  "+PortType+" passed to RXTXCommDriver.getCommPort()");
			}
		}
		catch( PortInUseException e )
		{
			if (debug) System.out.println(" Port "+PortName+" in use by another application");
		}

		if (debug) System.out.println("RXTXCommDriver:getCommPort:Exit");

		return null;


	}

	/**
	*	Yikes.
	*	Trying to call println from C for odd reasons
	**/

	public void Report(
		String arg
	)
	{
		System.out.println(arg);
	}
}