Java CD Audio Player Application

Jcd was an experiment to see if Java could be used for something more than simple applets. I chose to write a CD player because it required: interfacing to C, controlling hardware, threads, file IO, sockets, text parsing, image manipulation, data entry, graphical user interfaces. A great project for trying out a new language.

I'm not pushing it so much as a CD player, but as a sample Java application illustrating how some of the above can be tackled. I'm don't have a detailed reference on AWT, so some aspects of the GUI aren't the best. I'd welcome pointers as to what I've done right/wrong.

This is an application, not an applet, ie it accesses files and devices and can't be run under Netscape. You must use something that runs a Java application: eg Sun's JDK. If you've managed to get the AWT to run, you shouldn't have any trouble installing and running jcd.

Features:

• Play/Stop/Pause/Prev/Next/Eject/Volume control panel.
• Track/Index direct access by entry into the numeric display.
• Displays track, index, num-tracks, track-time/track-remaining/disc-rem'ing.
• Program play, continuous/single play, shuffle play.
• Xmcd CDDB artist/disc/track title lookup and display.
  • Xmcd CDDB database format and protocols courtesy of Ti Kan and Steve Scherf ( http://www.cddb.com).
  • Optional remote CDDB server lookup.
  • Autosave of remote lookups to local cache.
  • GUI window for creating/editing artist/title/track local cache entries.
• Icon button widget - e.g. play button, pause button light up when active.

Jcd is available from ftp://sunsite.unc.edu/pub/Linux/apps/sound/cdrom

VH-Man2html V1.5

I wanted users to be able to browse local man pages from a web browser under Caldera Linux 1.0. What does the resulting HTML look like? Here's a sample page for telnet(1)

The March 1997 Linux Journal includes my article on vh-man2html. If you're interested in more details of how it came about, and a summary of how it works, please see the article.

Update: I uploaded new tar.gz's and rpms for vh-man2html-1.5 on 9 March 1997 to fix a looping bug when a man directory contains no man pages. You can also just apply this small patch by doing as follows:

  mkdir fix-vh
  cp /home/httpd/cgi-bin/manwhatis /home/httpd/cgi-bin/mansec fix-vh
  (cd fix-vh; patch < ../vh.patch)
  cp fix-vh/manwhatis fix-vh/mansec /home/httpd/cgi-bin

Thanks to Mike Richardson (mike@quaking.demon.co.uk) for pointing out the cause of this problem.

Update: Redhat 4.1 has changed the location of grep/egrep to /bin. A quick fix is for Redhat 4.1 is to manually edit the /home/httpd/cgi-bin/manwhatis script changing the relevant references.

• "Verhoeven" man2html was written by Richard Verhoeven (NL:5482ZX35) at the Eindhoven University of Technology (email: rcb5@win.tue.nl). It works by reading the man page source directly. This is faster and more accurate, but you need the sources online (not a problem for Linux systems). There are other translators also called man2html around on the net. Richard has a web page that summarises what's around, and where you can also get the original source for man2html.c.
• RosettaMan (Rman) - which works by examining the formatted output pages from troff+tbl+eqn. RosettaMan can be obtained via anonymous ftp to ftp://ftp.cs.berkeley.edu:/ucb/people/phelps/tcltk/rman.tar.Z. Rosetta man's strength is that it can be used on systems where man page sources aren't supplied, eg SGI.

I've enhanced Richard's man2html so that it can also handle BSD mandoc-style man pages. I've also written some scripts to front-end man2html. They are designed to work with the man related commands and makewhatis info from Caldera/Redhat Linux. They generate indexes and perform searchs. The Indexes are generated on demand and update themselves when necessary. The indexes are ordered alphabetically with an A,B,C,... quick-link header and divided into man sections with section cross-links.

I've called my enhanced version of man2html, vh-man2html to distinguish it from both Richard's orginal and the many other scripts and programs of the same name. The V standing for Verhoeven's man2html, and the H for Hamilton's enhancements and packaging.

VH-Man2html privides the following functionality:

• man.html - Main page for access to man2html and man indexes.
• man2html - CGI binary that converts man pages to html.
• manwhatis - CGI script for a name and synopsis index organised by manual section. Generated from the makewhatis info.
• mansec - CGI script for a name only index for each section.
• mansearch - CGI script for a glimpse based full text search.
• netscape-man - script which emulates the man command, but uses netscape as its pager.
• /var/man2html - Cache directory for indexes and glimpse indexes.

• Can work as a remote man-page server.
• Support for BSD mandoc man pages. This means it can now cope with all the Caldera/Redhat man pages (eg telnet, ftp, and lpr are now converted correctly).
• The /usr/bin/netscape-man script performs like the man command but talks to a live (already running) netscape to present pages, e.g.

         netscape-man lpr         - netscape pops up lpr man page.
         netscape-man 8 sendmail  - pops up sendmail (8) man page.
         netscape-man 7 into      - pops up name+description index for sec 7.
         netscape-man 5           - pops up name-only index for sec 5.
         netscape-man -k pine     - pops up a glimpse text search for pine.
  

The latest vh-man2html (v1.5) and an optional glimpse Redhat rpm are available at ftp://ftp.redhat.com in the Incoming or in the contrib directory. It is also available at ftp.caldera.com.

Christoph Lameter (clameter@waterf.org) has put a version of vh-man2html into Debian Linux. His version is modified to work with man 2.3.

While working on man2html, I made some improvements to makewhatis that reduces its run time from 30 minutes to about 1.5 minutes on my 486DX2/66. It is now available as part of man-1.4g.tar.gz: at

ftp://sunsite.unc.edu/pub/Linux/apps/doctools/man

Linux/SGI Gr_Monitor

Linux 2.0 version available!

Gr_Monitor displays information about processes resisdent on a UNIX system. For each process it displays a bar graph of CPU, Memory, Resident Set Size, and Elapsed Time. The processes are grouped by username. Each username group sits on its own little plinth.

There are controls for translating, rotating, scaling, lighting and fog effects.

Gr_Monitor consists of two components. The first gathers data from the Linux/IRIX process file system. This info is piped to the second display process which displays the data. By using rsh its possible to run the gather program on one machine and the display program on another. The display program input format is quite flexible, and could be used to display other kinds of data without any modification.

Gr_Monitor is something I hacked together to learn more about OpenGL, SGI's open standard for 2D/3D graphics. The whole thing was developed under Linux using the Mesa, OpenGL look-a-like, library.

I now have SGI process file-system version of process info gatherer. I haven't found an SGI home for it. So if you're interested email me. Gr_Monitor is very slow on a typical 486 with a non-accelerated graphics card (I don't know if an accelerated card would help). But it is fun to watch, especially on a machine where processes or users are coming and going. It is very useful for spotting hogs and uninhibited growth.

I have a larger 32k gif preview of what a gr_monitor display looks like.

Gr_monitor version 0.53 is available for anonymous ftp from sunsite.unc.edu where it normally resides in /pub/Linux/system/status. The tar includes both Linux and SGI source code.

Getdate - Safely sync your system date

Getdate is a utility that queries an RFC 868 time server and adjusts or sets the local date and time. It's useful for querying and copying the date/time from other Internet hosts. It will work correctly across time zones.

Get uses the UNIX adjtime() call so that it can be safely set up as a cron job. It can be set to reject hosts that respond slowly, or that vary too greatly from the local time. It should work on most of the modern UNIX variants.

The getdate man page is available for perusal.

The latest getdate-1.1 has been dropped off at ftp.redhat.com where it should move from /pub/Incoming to /pub/contrib. Getdate 1.0 is available from sunsite.unc.edu in /pub/Linux/system/network/misc/getdate-1.0.tar.gz.

Fm.py - Some example Python/Tkinter code

Python is my favorite programming language. Here is a short example of how to program the new Python 1.3 with Tkinter. The code demonstrates how to do things like:

• Data entry forms.
• Simple labelled entry widgets.
• Labled entry widgets with dropdown menu help.
• Text entry widgets with a vertical scrollbar.
• Spread-sheet-style cellular views of data with scrollbars and arrows keys used for cell movement.
• Forms imbedded in scrollable canvases.

You can view the source code to the forms module fm.py and the small test program testfm.py. My code isn't the best python (I'm still learning). It's just over 900 lines of python including comments.

I originally had something similar written in Tcl/Tk, which I used in TkCD (see next heading). It's nice to see that python can be used far more cleanly without resorting to global variables and evals.

TkCD Audio CD Player

TkCD is a GUI CD player interface I developed for the Linux operating system. TkCD 1.0 is actually a Tk/Tcl front end for CDplayer 2.0 by Mark Buckaway (mark @datasoft.com). Currently CDplayer 2.0 works on Linux and Coherent, but should be portable to any system supporting Sun CDROM ioctl. TkCD was developed using Tk/Tcl (an embeddable scripting language and GUItoolset). The entire application is available via anonymous ftp from sunsite.unc.edu where it resides in /pub/Linux/apps/sound/cdrom as part of the CDplayer-2.0 distribution.

TkCD needs a small patch to work with tcl 7.4. Just apply it to your installed tkcd script:

	cd  to-where-tkcd-lives
	patch < patch-file-name
	

If you are thinking of obtaining TkCD you might like to preview the TkCD interface before you consider ftp'ing it.(13373 byte gif).

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Last modified: Wed Jul 16 22:59:56 NZST