1. Introduction

    Xdbx implements an X Window interface to the dbx debugger.  It is written 
    using X11R3 Toolkit Intrinsics and Athena widgets.  

    Xdbx provides buttons and action handlers for a subset of dbx commands:
	 run, cont, next, step, stop at, stop in, delete,
	 up, down, print, print *, func, file, quit

    Xdbx uses the regular expression routines provided in GNU Emacs 
    distribution.  The files regex.c and regex.h are included in this
    distribution.  Regex.c is slightly modified to include <alloca.h>
    to compile under SunOS 4.0.

2. Installation

    Xdbx supports both Berkeley dbx and Sun dbx.  Sun dbx, available on
    the Sun workstations, is an enhanced and extended version of Berkeley dbx.
    If you run Sun dbx with no arguments, you get a dbx prompt:
      (dbx)
    If you run Berkeley dbx with no arguments, you would get something like:
      dbx version 2.0 of 11/17/87 21:23
      Type 'help' for help.
      enter object file name (default is `a.out'):

    If you are using Berkeley dbx, you probably have to edit the Imakefile to
    include the -DBSD flag.  
    Generate your own Makefile from Imakefile using imake and makedepend.

    Xdbx has been tested on Sun 3 running Sun 4.2BSD Unix Release 3.4, 
    and VAXstation II/GPX running Ultrix 2.2, both under uwm.

3. Bugs

   * Xdbx does not work properly under SunOS 4.0 because of a problem in 
     disabling the packet mode (TIOCPKT) of the pseudo-terminal.  If the
     packet mode is not disabled, each read from the master will return 
     data written previously to the slave (dbx commands entered would 
     reappear), and each newline character is incorrectly mapped to a 
     carriage return and a newline during text display.
   * The above problem sometimes appear on Sun 3 under release 3.4.  If you 
     see ^M at the end of each line in the dialog window, quit xdbx, try 
     again by either logging out and in (hopefully this will reset the pty),
     or by doing an rlogin to try another pty.
   * Typing control-C in the dialog window fails to interrupt dbx.
   * The file command button does not unhighlight itself.
   * Stuffing text to a window outside the xdbx window will sometimes give:
	X Toolkit Error: AtomPtr was not initialized

   Please send any comments, bug reports, bug fixes, enhancements to:

	Po Cheung
	Department of Electrical and Computer Engineering
	University of Texas
	Austin, TX 78712
	po@volta.ece.utexas.edu


4. Acknowledgements

    I would like to express my sincere thanks to Dr. Joe Rahmeh for his help
    and guidance, without him this would not have been possible.  His idea
    to use GNU regular expression package made it much easier for xdbx to
    support both versions of dbx.  I must also thank my brother, Yin Cheung,
    for his support and encouragement throughout the past four months.  Many 
    thanks go to Adrian Lao, Mike Schoenfelder, Yah Bin Sim and Nasr Ullah 
    for making this release date possible.
