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822 lines
28 KiB
822 lines
28 KiB
/*-------------------------------------------------------------------------
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| rxtx is a native interface to serial ports in Java.
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| Copyright 1997-2004 by Trent Jarvi taj@www.linux.org.uk
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| This library is free software; you can redistribute it and/or
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| modify it under the terms of the GNU Library General Public
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| License as published by the Free Software Foundation; either
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| version 2 of the License, or (at your option) any later version.
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| This library is distributed in the hope that it will be useful,
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| but WITHOUT ANY WARRANTY; without even the implied warranty of
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| Library General Public License for more details.
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| You should have received a copy of the GNU Library General Public
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| License along with this library; if not, write to the Free
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| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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--------------------------------------------------------------------------*/
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This is the INSTALL file for RXTX. Thu Jul 7 19:46:26 EDT 2005
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If, while following the instructions, you find this file unclear or incorrect
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please make a note and email the details to taj@www.linux.org.uk.
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A note about rxtx 2.1:
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rxtx 2.1 replaces the entire CommAPI. Every effort is made to conform to
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CommAPI but out of respect for our friends at Sun the package name of 2.1 has
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been moved to gnu.io. A script is offered in contrib/ChangePackage.sh that
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will switch source tree's between javax.comm and gnu.io.
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See Sun's CommAPI license for more details on why this decision was made.
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If you would like to use javax.comm, use rxtx 1.4 with Sun's CommAPI.
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A note on Mac OS X:
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Go to the MacOSX file for install instructions.
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1. INSTALL INSTRUCTIONS IN OTHER LANGUAGES
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A. Japanese
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2. BUILDING COMMAPI SUPPORT
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A. Quick Install
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B. Uninstalling Sun's comm.jar
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C. installing javax.comm.properties.
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D. Add RXTXcomm.jar to your CLASSPATH.
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E. Build and Install the jar.
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F. Where did everything end up?
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G. Compiling for Win32 support
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3. COMMON PROBLEMS
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A. java.lang.UnsatisfiedLinkError: nSetOwner while loading driver
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gnu.io.RXTXCommDriver
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B. Exception in thread "main" java.lang.UnsatisfiedLinkError:
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no rxtxSerial in java.library.path
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C. I Can Not Open the Port.
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D. java.lang.NoClassDefFoundError: gnu/io/CommPort
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E. The Compiler Cannot Find Java Include Files
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F. Configure says 'unterminated sed command' and stops
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G. Java Can Not Find libstdc++-libc6.0-1.so.2
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H. BlackBox Can Not Handle all the ports!
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I. Illegal use of nonvirtal function call!
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J. My libc5 Linux system is generating SIGSEGV
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K. AM_PROG_LIBTOOL not found in library
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L. Problems with RMISecurityManager()
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M. Which Wires Should be Connected?
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N. Which Device Should be Used?
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O. It Did Not Work!
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P. Which jdk should be used?
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Q. How does rxtx detect ports? Can I override it?
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R. How can I use Lock Files with rxtx?
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S. How can I tell which version of rxtx is installed?
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T. What Type of Latency can I expect with RXTX
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U. I got rxtx working on a new OS but I can't read from the port
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V. My ThinkPad is Not Working!
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4) APPLETS
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A. Using Applets
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-------------------------------------------------------------------------------
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1. INSTALL INSTRUCTIONS IN OTHER LANGUAGES
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A. Japanese
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Instructions are available in Japanese at
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The instructions are fairly old but should help.
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http://www.geocities.co.jp/Technopolis/4789/settei.htm#id1
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Thanks to Masayuki "Tencho" Yamashita <tencho@venus.kanazawa-it.ac.jp>
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home page http://www.geocities.co.jp/Technopolis/4789/
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A copy of these install instructions is provided in
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install-japanese.html
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We will gladly include instructions in any language provided. Tencho
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was the first to contribute instructions in another language.
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2. BUILDING COMMAPI SUPPORT
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The following is concerned with building and installing commapi
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support with Sun's CommAPI package. A full stand alone version of
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rxtx is in the CVS archive for interested developers.
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A. Quick Install
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The following packages are used to build rxtx:
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autoconf-2.59
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automake-1.9.5
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libtool-1.5.18
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gnu make-3.79.1 On some systems like FreeBSD this is
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called gmake
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jdk 1.3 or newer
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With the packages installed, proceed to build and install rxtx.
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$ tar -xzvf rxtx-2.1.tar.gz
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$ cd rxtx-2.1
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$ ./configure (follow the instructions)
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$ make install (gmake if your system uses that convention)
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Read "R. How can I use Lock Files with rxtx?"
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One catch that has showed up... you cannot have spaces in the path.
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for instance: /home/jarvi/test build/rxtx/... will cause problems.
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----^
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If that does not work or you do not want a script messing with the
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system, read on..
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B. Uninstalling Sun's comm.jar
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Sun's comm.jar is not required. It is a valid option on
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some platforms. IT WILL CREATE CHAOS if you have it installed
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while trying to build rxtx 2.1.
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http://java.sun.com/products/javacomm/index.html
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C. Installing javax.comm.properties.
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javax.comm.properties is not currently required by rxtx-2.1
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D. Add RXTXcomm.jar to your CLASSPATH.
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jdk-1.1:
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make sure /usr/local/java/lib/RXTXcomm.jar is in your
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CLASSPATH. If you want to use apps that require
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RXTXcomm.jar.
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in bash:
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$ export CLASSPATH=/usr/local/java/lib/RXTXcomm.jar:.
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jdk-1.2 and newer:
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No changes are needed.
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E. Build and Install the jar.
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configure configure supports build directories.
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configure requires javac in its path or
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JAVA_HOME set to grab some java system
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properties.
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make to build RXTXcomm.jar and the libraries
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make install to place the jar and libraries in the correct
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location
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You may select the JDK you wish to build with using $JAVA_HOME
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For example:
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export JAVA_HOME=/usr/local/java
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Otherwise, configure grabs the JDK from your PATH.
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F. Where did everything end up?
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Lets assume the top java directory is /usr/local/java
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jdk-1.2 the files go in
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/usr/local/java/jre/lib/ext/RXTXcomm.jar
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/usr/local/java/jre/lib/$(ARCH)/librxtxSerial.so.
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/usr/local/java/jre/lib/$(ARCH)/librxtxParallel.so.
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/usr/local/java/jre/lib/$(ARCH)/lib/...
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jdk-1.1.* the files go in
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/usr/local/java/lib/RXTXcomm.jar
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/usr/lib/librxtxSerial.so.
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/usr/lib/librxtxParallel.so.
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/usr/lib/...
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The librxtxSerial.so librxtxParallel.so are placed in
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/usr/lib so people don't have to change with their
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LD_LIBRARY_PATH.
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G. Compiling for Win32 support
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Get the Sun CommAPI if you want a plug-in solution. The code
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is provided for people that may have demanding needs and coding
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ability.
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There is only serial port code at this time.
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Three ways of compiling win32 libraries are offered:
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mingw32 tools in DOS
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lcc tools in DOS
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cross-compiling from Linux
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----------------- mingw32 tools in DOS -----------------------
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Install mingw32 http://www.mingw.org
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Install a jdk http://java.sun.com/j2se
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Make sure the ming32\bin and jdk\bin directories are in your
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path.
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In the rxtx top directory to the following:
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mkdir build
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copy Makefile.mingw32 build\Makefile
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cd build
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edit the Makefile and make sure the directories are correct.
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execute the following:
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make
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make install
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----------------- lcc tools in DOS ---------------------------
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Install a jdk http://java.sun.com/j2se
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Install lcc http://www.cs.virginia.edu/~lcc-win32/
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A make file (Makefile.lcc) for compiling rxtx with lcc
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contributed by Valentin Pavlov
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You will need a config.h file in the src directory. Other
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builds usually generate them automatically. The following
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should work.
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#define HAVE_FCNTL_H
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#define HAVE_SIGNAL_H
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#undef HAVE_SYS_FCNTL_H
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#undef HAVE_SYS_FILE_H
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#undef HAVE_SYS_SIGNAL_H
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#undef HAVE_TERMIOS_H
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#undef HAVE_SYS_TIME_H
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if you know how to create the above in a dos Makefile send in the changes.
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the following commands should then work fine on the command
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line.
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cd src
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make -f ..\Makefile.lcc
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----------------- cross-compiling from Linux -----------------
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Grab ming32:
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Wayne Roberts contributed the version used by the maintainer.
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(Wayne is largely responsible for bringing rxtx back to win32.)
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http://www.linuxgrrls.org/~taj/crossmingw32-2.95-1.i386.rpm
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A more current version can be obtained:
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http://www.devolution.com/~slouken/SDL/Xmingw32/crossgcc/index.html
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prebuilt Binaries:
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http://www.devolution.com/~slouken/SDL/Xmingw32/mingw32-linux-x86-glibc-2.1.tar.gz
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I built the dll with jdk-1.2.2 for linux using jdk-1.2.2
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include files from the win32 JDK.
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Make sure that ming32 bin dir is the first in your path (at
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least before /usr/bin/gcc)
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$ export PATH=" \
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/usr/local/cross-tools/i386-mingw32/bin/: \
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$PATH:/usr/X11R6/bin:/usr/local/java/bin: \
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/usr/local/java/jre/bin/:"
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Place Sun jdk 1.2.2 win32 include files in a known location.
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$ mkdir /home/jarvi/win32java
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$ cp -r /mnt/win98//java/include /home/jarvi/win32java
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If you are developing win32 support you may want to
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export the location to make the config script
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non interactive
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$ export WIN32INCLUDE=/home/jarvi/tools/win32-include
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run configure to generate a Makefile
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$ cd /home/jarvi/rxtx-*
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$ mkdir build
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$ cd build
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$ ../configure --target=i386-mingw32 \
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--host=i386-redhat-linux
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build the class files and dll.
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$ make
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the files will be located in
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rxtx-*/build/...
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If you're looking at rxtx as an example of cross-compiling you
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may be interested in looking at the examples provided at:
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ftp.xraylith.wisc.edu
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/pub/khan/gnu-win32/mingw32/misc/java-jni-examples.zip
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3. COMMON PROBLEMS
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A. I get java.lang.UnsatisfiedLinkError: nSetOwner while loading driver
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gnu.io.RXTXCommDriver when using rxtx.
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SetOwner appears to be some win32 call.
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Do not use Sun's win32 CommAPI files. Get the Solaris version.
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"javacomm20-x86.tar.Z" and rxtx-1.4 if you want Sun's solution.
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See Also: 2-B. Installing Sun's comm.jar (IE its not needed at all)
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B. Exception in thread "main" java.lang.UnsatisfiedLinkError: no rxtxSerial in
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java.library.path
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librxtxSerial.so is located in the wrong directory. Here is an example
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$ mv /usr/local/java/jre/lib/i386/librxtxSerial* /usr/local/lib
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$ java BlackBox
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Exception in thread "main" java.lang.UnsatisfiedLinkError: no rxtxSerial
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in java.library.path
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at java.lang.ClassLoader.loadLibrary(Compiled Code)
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at java.lang.Runtime.loadLibrary0(Compiled Code)
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at java.lang.System.loadLibrary(Compiled Code)
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at gnu.io.NativePort.<clinit>(NativePort.java:32)
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at gnu.io.RXTXPort.<init>(Compiled Code)
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at gnu.io.RXTXCommDriver.getCommPort(Compiled Code)
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at gnu.io.CommPortIdentifier.open(Compiled Code)
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at SerialPortDisplay.openBBPort(Compiled Code)
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at SerialPortDisplay.<init>(Compiled Code)
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at BlackBox.addPort(Compiled Code)
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at BlackBox.main(Compiled Code)
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... lets fix it.
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Solution 1: move the file to a place that works
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$ mv /usr/local/lib/librxtxSerial.* /usr/local/java/jre/lib/i386/
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Solution 2: add the location of librxtxSerial to LD_LIBRARY_PATH
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$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/
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Solution 3: pass the location in on the command line
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$ java -Djava.library.path=/usr/local/lib/ ...
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C. I Can Not Open the Port.
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If you're not able to open the port (read the errors carefully) then you
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may not have permission to use the device. Redhat Linux ships with the
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following permissions:
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crw-r--r-- /dev/ttyS?
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Users need to be able to read and write with serial communication...
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chmod 666 /dev/ttyS?
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should fix the problem. Be sure to check the file CommAPI for common
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mistakes.
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Make sure that the user can create lock files see R.
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D. java.lang.NoClassDefFoundError: gnu/io/CommPort
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RXTXcomm.jar is probably not in your classpath or not located in
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the proper directory.
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for example, lets not include RXTXcomm.jar
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export CLASSPATH=../java/lib/classes.zip
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$ java BlackBoxException in thread "main"
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java.lang.NoClassDefFoundError: gnu/io/CommPort
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E. The Compiler Cannot Find Java Include Files
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Check to top of the Makefile to make sure we agree on the location of
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the include files that came with the jdk. Specifically:
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JAVAINCLUDE = -I /usr/local/java/include/
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JAVANATINC = -I /usr/local/java/include/genunix
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also check the classpath
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CLASSPATH = ...
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F. Configure says 'unterminated sed command' and stops
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Unterminated sed command errors usually result from `find` producing
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unexpected results. If you are unsure remove all comm.jar and
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configure to place in in the correct place.
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G. Java Can Not Find libstdc++-libc6.0-1.so.2
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jdk-1.2 on redhat systems may note that Java complains about not being
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able to find libstdc++-libc6.0-1.so.2. A symbolic link can be used to
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get around this feature.
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ln -s /usr/lib/libstdc++ /usr/lib/libstdc++-libc6.0-1.so.2
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ls -l /usr/lib/libstdc++-libc6.0-1.so.2
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/usr/lib/libstdc++-libc6.0-1.so.2 -> libstdc++.so.2.8.0
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H. BlackBox Can Not Handle all the ports!
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BlackBox has a hard coded limit in BlackBox.java that prevents it from
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running if you don't specify a port. We are considering alternative
|
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ways of handling the large number of port names in Unix. The line in
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question
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is:
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portDisp = new SerialPortDisplay[50];
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just change 50 to say 256.
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I. Illegal use of nonvirtal function call!
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Exception in thread "main" java.lang.VerifyError: (class:
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gnu/io/RXTXPort$SerialOutputStream, method: flush signature: ()V)
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Illegal use of nonvirtual function call
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at gnu.io.RXTXCommDriver.getCommPort(Compiled Code)
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at gnu.io.CommPortIdentifier.open(Compiled Code)
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at SerialPortDisplay.openBBPort(Compiled Code)
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at SerialPortDisplay.<init>(Compiled Code)
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at BlackBox.addPort(Compiled Code)
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at BlackBox.main(Compiled Code)
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"1.1 compilers sometimes generate code that won't verify under 1.2.
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If you don't have the sources for the offending class to recompile with
|
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a 1.2 javac, the only solution I know of is to launch the VM with the
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-noverify option.
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Louis"
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In other words start with a fresh build directory, rebuild, and
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reinstall to avoid the problem.
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J. My libc5 Linux system is generating SIGSEGV
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|
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Older Linux Systems (libc5) should upgrade to a glibc system with
|
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libpthread-0.7 or newer. We have run into many problems with older
|
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libraries. SIGSEGV was the most common symptom. Reported by Peter
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Bennett <bencom@bencom.co.nz>
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K. AM_PROG_LIBTOOL not found in library
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|
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cd. && aclocal
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aclocal:configure.in: 23: macro 'AM_PROG_LIBTOOL' not found in library
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make:***[aclocal.m4]Error 1
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If you're positive things are setup right you may try the autogen.sh
|
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script to try regenerating the scripts with your tools.
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L. Problems with RMISecurityManager()
|
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|
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Please see the file RMISecurityManager.html
|
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|
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M. Which Wires Should be Connected?
|
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|
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With the DB25 use 2 (TX), 3 (RX) and 7 (GD) to connect to the device.
|
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With the DB9 use 2 (RX), 3 (TX) and 5 (GD) to connect to the device.
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You will need to hook up more than that for hardware flow control.
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N. Which Device Should be Used?
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Linux serial ports should use /dev/ttyS?
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specialx, cyclades and isdn4 linux have been reported to work.
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as many as 64 ports have worked at one time.
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FreeBSD uses cuaa?
|
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netbsd uses tty0?
|
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Irix uses ttyd? ttym? ttyf?
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HP-UX uses tty0p? tty1p?
|
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BeOS uses /dev/ports/serial?
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Win32 uses COM?
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O. It Did Not Work!
|
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|
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There are sure to be bugs. The goal is to make the install as painless
|
|
as possible. Send back comments if something could be easier.
|
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|
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If you run into a problem building the rxtx package please include the
|
|
output generated by the following script.
|
|
|
|
---------------clip-----------------
|
|
#!/bin/sh
|
|
which java
|
|
java -version
|
|
uname -a
|
|
autoconf --version
|
|
automake --version
|
|
libtool --version
|
|
make --version
|
|
---------------clip-----------------
|
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|
|
Here's what's on my system for comparison. Older make is known to cause
|
|
problems.
|
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|
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java 1.4
|
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autoconf-2.53
|
|
automake-1.6.3
|
|
libtool-1.4.2
|
|
gnu make-3.79.1
|
|
|
|
mail any bugs to taj@www.linux.org.uk.
|
|
|
|
P. Which jdk should be used?
|
|
|
|
Ideally any jdk would be fine. Here is a list of jdk's tried on
|
|
RedHat 6.0/kernel 2.2.17pre13 with various versions of glibc.
|
|
|
|
Sun IBM Blackdown
|
|
2.1.2_006 1.3.0 1.1.8v1
|
|
green native green native green native
|
|
------------------------------------------
|
|
glibc-2.1.1-6 | OK | *1 | *2 | *2 | OK | *3 |
|
|
-------------------------------------------
|
|
glibc-2.1.2-11 | OK | *1 | OK | OK | OK | OK |
|
|
-------------------------------------------
|
|
glibc-2.1.2-17 | OK | *1 | OK | OK | OK | OK |
|
|
-------------------------------------------
|
|
glibc-2.1.3-15 | OK | *1 | OK | OK | OK | OK |
|
|
-------------------------------------------
|
|
|
|
1) BlackBox (a demo application shipped with CommAPI locks after multiple
|
|
open()/close()
|
|
|
|
2) java wont start "Unable to load /usr/local/java/jre/bin/libhpi.so: symbol
|
|
sem_wait, version GLIBC_2.1 not defined in file libpthread.so.0 with link time
|
|
reference Could not create the Java virtual machine."
|
|
|
|
3) java wont start "error in loading shared libraries:
|
|
/usr/local/java/bin/../lib/i686/native_threads/libjava.so: symbol sem_init,
|
|
version GLIBC_2.1 not defined in file libpthread.so.0 with link time reference"
|
|
|
|
Conclusion? Avoid Sun's native threads unless you can figure out whats going
|
|
wrong.
|
|
|
|
Q. How does rxtx detect ports? Can I override it?
|
|
|
|
rxtx tries to detect ports on by scanning /dev for files matching any
|
|
of a set of known-good prefixes, such as 'ttyS', 'ttym', and so on.
|
|
Any ones that exist, are supposed to be good for the current operating
|
|
system, and that can be read and written are offered back from
|
|
CommPortIdentifier.getPortIdentifiers(), and only these can be used as
|
|
ports.
|
|
|
|
If you wish, you can set the system properties gnu.io.rxtx.SerialPorts
|
|
and gnu.io.rxtx.ParallelPorts. If either of these is set, then no
|
|
scanning will be carried out and only the specified ports will be
|
|
available. You can use this to make one platform look like another,
|
|
to restrict Java access to ports, or possibly for other reasons. For
|
|
example
|
|
|
|
java -Dgnu.io.rxtx.SerialPorts=/dev/cua/a:/dev/cua/b com.foo.MyApp
|
|
|
|
will look kind of like Solaris, if you have created the appropriate
|
|
device nodes.
|
|
|
|
A note on Linux port enumeration. We have set most ports aside. Once the
|
|
number of possible devices started getting into the thousands, checking them
|
|
all made little sense. Look in RXTXCommDriver.java and search for Linux.
|
|
|
|
You will see that only /dev/ttyS* is searched but the possible addition ports
|
|
that can be used are listed under it. Just copy the few you need.
|
|
|
|
R. How can I use Lock Files with rxtx?
|
|
|
|
Redhat users. Note that Redhat changed group uucp to group lock with Redhat
|
|
7.2.
|
|
|
|
Mandrake users. Note that /var/lock needs to be group uucp for this to work.
|
|
|
|
Mac OS X users. Note that you may need to create the lock directory with group uucp ownership. There is a script in contrib called fixperm.sh to help with
|
|
this on Mac OS X.
|
|
|
|
RXTX uses lock files by default. configure --disable-lockfiles to generate
|
|
rxtx libraries without lock files. Its strongly recommended that you do
|
|
use lock files to prevent rxtx from stomping on other programs using serial
|
|
ports.
|
|
|
|
Lock files are used to prevent more than one program accessing a port at a
|
|
time. Lock files require a bit of sysadmin to work properly..
|
|
|
|
Rxtx has support for lock files on Linux only. It may work on other
|
|
platforms but read the source before blindly trying it.
|
|
|
|
Before you use lock files you need to do one of two things:
|
|
|
|
1. Be the root or uucp user on your machine whenever you use rxtx
|
|
2. add the specific user that needs to use rxtx to the group uucp.
|
|
(preferred)
|
|
|
|
To add a user to the uucp group edit /etc/group as root and change the
|
|
following:
|
|
uucp::14:uucp
|
|
to something like:
|
|
uucp::14:uucp,jarvi
|
|
In this case jarvi is the login name for the user that needs to use lock files.
|
|
Do not change the number (14). Whatever is in your group file is correct.
|
|
|
|
User jarvi in this case can now use rxtx with lock files.
|
|
|
|
The lock file code does not support kermit style lock files or lock files in
|
|
/var/spool. Its sure to fail if you're using subdirectories in /dev or do not
|
|
have /dev.
|
|
|
|
Still cant get things to run under a root account?
|
|
|
|
Vadim Tkachenko writes:
|
|
|
|
"Maybe you remember - couple of months back I've run into inability to
|
|
run the JDK 1.3+ from under root account.
|
|
|
|
Today, absolutely suddenly, something clicked in my head and the cause
|
|
was found: libsafe. To make JDK work, it is enough to disable libsafe
|
|
(unset LD_PRELOAD)."
|
|
|
|
As another option it is possible to use a Lock File Server. In this case,
|
|
a server runs in group uucp or lock and rxtx then connects to localhost
|
|
to lock and unlock the port. The server and install instructions can be
|
|
found in src/lfd. RXTX will need to be configured to use the server:
|
|
|
|
configure --enable-lockfile_server
|
|
|
|
Any user can then lock the ports if they are not already locked.
|
|
|
|
S. How can I tell which version of rxtx is installed?
|
|
|
|
Version information is not documented in Sun's CommAPI so this is probably
|
|
unique to RXTX.
|
|
|
|
As of rxtx-1.5-4 and rxtx-1.4-6 a class has been added to allow developers to
|
|
check which version of rxtx is installed. The class is RXTXVersion.
|
|
|
|
The static method: System.out.println(RXTXVersion.getVersion());
|
|
|
|
will print the rxtx version as a String in the following format:
|
|
|
|
"RXTX-MAJOR.MINOR-PATCH".
|
|
|
|
an example would be:
|
|
|
|
"RXTX-1.5-4"
|
|
|
|
A change in the MAJOR version would suggest you're in trouble.
|
|
|
|
Odd MINOR version are reserved for development. Even MINOR versions are
|
|
reserved for 'stable' releases.
|
|
|
|
PATCH is used to differentiate incremental releases of the MINOR releases.
|
|
|
|
CommPortIdentifier is expected to support getVersion() in the RXTX-1.5 series.
|
|
|
|
T. What Type of Latency can I expect with RXTX
|
|
|
|
frantz <fcapiez@club-internet.fr> put RXTX under a scope and found
|
|
the following:
|
|
|
|
RXTX currently has a latency of 150-200ms on a PII at 450mhz.
|
|
The latency can be reduced to 70-80ms by reducing the usleep()
|
|
value in SerialImp.c:eventLoop() to usleep(5000)).
|
|
|
|
Much lower latencies should be possible but the maintainer does not
|
|
have equipment to test changes.
|
|
|
|
He is going to look at this further. He needs 20 ms or less latency.
|
|
|
|
U. I got rxtx working on a new OS but I can't read from the port
|
|
|
|
> Now my java program starts up nicely without complaining. However, it does
|
|
> never read any data from the serial port. It looks like it can write data,
|
|
> because if I start a terminal program after I tried to run my program, I get
|
|
> all the return stuff from the modem that my program wrote.
|
|
>
|
|
> I hacked around abit and found out that it hangs in the select() call which
|
|
> simply never returns.
|
|
>
|
|
On Sun, 28 Jan 2001, Baldur Norddahl wrote:
|
|
> HPUX 11:
|
|
>
|
|
> As I wrote to the mailinglist I had some wierd problems where it apparently
|
|
> could write data to the modem, but not read anything back. My terminal
|
|
> programs had no problem using the port. A few days after I reported the
|
|
> problem to the mailinglist, I had given up for now, but then I noticed that
|
|
> it suddenly worked! So it remains a mystery what was wrong as I did not
|
|
> change anything at all, neither in my program nor on the host.
|
|
>
|
|
> Baldur
|
|
>
|
|
|
|
I suspect two java applications had the port open. Its easy to do while
|
|
developing. Perhaps <ctl> z instead of <ctl> c was entered.
|
|
|
|
This is the reason for adding lockfile support to rxtx. If another application
|
|
has opened the port, a second application will appear to not be able to
|
|
read or get only part of the data. ..because the first one is reading. Only
|
|
one of the select()s are waken.
|
|
|
|
Its possible to put lockfile support in for HPUX if it is known where other
|
|
applications place their lockfiles. The easiest way to find out where is
|
|
to fire up minicom, kermit, ... and see where its lockfile is placed.
|
|
|
|
Here are the known suspects:
|
|
|
|
const char *lockdirs[]={ "/etc/locks", "/usr/spool/kermit",
|
|
"/usr/spool/locks", "/usr/spool/uucp", "/usr/spool/uucp/",
|
|
"/usr/spool/uucp/LCK", "/var/lock", "/var/lock/modem",
|
|
"/var/spool/lock", "/var/spool/locks", "/var/spool/uucp",NULL
|
|
};
|
|
|
|
freebsd uses /var/spool/uucp/, linux uses /var/lock those are the only two
|
|
I've done so far. Adding the support is trivial once a directory is
|
|
decided upon.
|
|
|
|
Lockfiles are rather simple. when an application opens a port it first checks
|
|
if there is a file with the ports name. If there is it grabs the PID from the
|
|
file. If that PID is still active the application does not open the port.
|
|
|
|
If the PID is not active or there is no lockfile, the application creates one
|
|
with its own PID in it.
|
|
|
|
The confusion starts when you have to decide where (see above) to put the
|
|
lockfile, what the name format is for the file and how to store the PID.
|
|
|
|
rxtx follows The File System Hierarchy Standard http://www.pathname.com/fhs/
|
|
on linux. I'm not positive what is normal on other OS's.
|
|
|
|
more reading:
|
|
|
|
The File System Hierarchy Standard
|
|
http://www.pathname.com/fhs/
|
|
|
|
FSSTND
|
|
ftp://tsx-11.mit.edu/pub/linux/docs/linux-standards/fsstnd/
|
|
|
|
Proposed Changes to the File System Hierarchy Standard
|
|
ftp://scicom.alphacdc.com/pub/linux/devlock-0.X.tgz
|
|
|
|
"UNIX Network Programming", W. Richard Stevens,
|
|
Prentice-Hall, 1990, pages 96-101.
|
|
more reading:
|
|
|
|
V. My ThinkPad is Not Working!
|
|
|
|
Scott Burleigh <Scott.Burleigh@jpl.nasa.gov> writes:
|
|
|
|
For your files, and in case anybody asks in the
|
|
future, IBM Thinkpads ship with the external serial port
|
|
*disabled* by default. The Thinkpad configuration utility
|
|
supplied with the machine (under Windows) says it's enabled,
|
|
and the device manager in the System dialog of the Control
|
|
panel says it's enabled, but they lie. In order to enable the
|
|
port you have to use the old DOS ps2.exe bios configuration
|
|
utility which, under Windows 2000, is in
|
|
c:\Program Files\Thinkpad\utilities:
|
|
|
|
ps2 sera enable
|
|
|
|
Until you do, "setserial -ga /dev/ttyS0" will always tell you
|
|
the UART is unknown.
|
|
|
|
|
|
|
|
4. APPLETS
|
|
|
|
More info is needed on signing applets. This is an exchange from the rxtx mail-
|
|
list.
|
|
|
|
A. Using Applets
|
|
|
|
prashantg10@yahoo.com asked:
|
|
|
|
Hi All !
|
|
|
|
I am trying to use applet on thin terminal which has
|
|
Linux base Kernel.For testing I am using Linux
|
|
machine.I have install all the required components.
|
|
e.g. JDK, RXTX. Everthing is fine. BlackBox runs ,even
|
|
my application runs. When It comes to applet,
|
|
everything is halts. It does not even show the listing
|
|
of ports. Is it because applet can't run under root
|
|
account or what might be the reasons. Can anybody tell
|
|
me solution.
|
|
|
|
Son To <son@openbx.net> replied:
|
|
|
|
Java applets run withing the sandbox of the security manager.
|
|
Applets must be signed to access the com port, but for development
|
|
purposes you can put
|
|
|
|
user_pref("signed.applets.codebase_principal_support", true);
|
|
|
|
in your prefs.js located in ~/.mozilla/default/XYYrandomDirName
|
|
|
|
I didn't use Java applet for my application. I used XUL and CSS for
|
|
the GUI development and used mozilla Javascript SOAP library to
|
|
communicate with apache Axis webservice backend which uses RXTX to
|
|
access the com port.
|
|
|
|
--
|
|
Trent Jarvi
|
|
taj@www.linux.org.uk
|
|
-------------------------------------------------------------------------------
|
|
You made it this far.. what is one more line.
|
|
|
|
Sun, Solaris and Java are registered trademarks of Sun Microsystems, Inc.
|
|
|
|
|
|
reminder:
|
|
|
|
redhat 7.1 needs:
|
|
export LD_ASSUME_KERNEL=2.2.5
|