0. INTRODUCTION
This is a port and cleanup of my bash debugger bashdb
(http://bashdb.sf.net). 

The command syntax generally follows that of the GNU debugger gdb.

However this debugger depends on a number bug fixes and of debugging
support features that are neither part of the POSIX 1003.1 standard
and are not in current "stable" zsh releases. In particular, the
"functrace" function should always report filenames and absolute line
numbers.  Also both "functrace" and "funcstack" should include
source'd files in their arrays.

1. SETUP

To get the code, install git and run in a zsh shell:

  git-clone git://github.com/rocky/zshdb.git
  cd zshdb
  ./autogen.sh  # Add configure options. See ./configure --help 

If you've got a suitable zsh installed, then
  make && make test

To try on a real program such as perhaps /etc/zsh/zshrc:
  ./zshdb /etc/zsh/zshrc # substitute .../zshrc with your favorite zsh script

If you are happy and "make test" above worked, install via:
  sudo make install

and uninstall with 
  sudo make uninstall # ;-)

See INSTALL for generic configure installation instructions.

2. WHAT'S HERE, WHAT'S NOT and WHY NOT

What's missing falls into a two categories:

  * Stuff that can be ported in a straightforward way from bashdb
  * Stuff that needs additional zsh support

Of the things which can be ported in a straight-forward way, however
some of them I want to revise and simplify. In some cases, the fact
that zsh has associative arrays simplifies code. On other cases, the
code I wrote needs refactoring and better modularization.

Writing documentation is important, but an extensive guide will have
to wait. For now one can consult the reference guide that comes with
bashdb: http://bashdb.sf.net/bashdb.html There is some minimal help to
get a list of commands and some help for each.

3. WHAT'S NOT HERE YET IN DETAIL

3.a) Showing frame arguments

This can done with or without support from zsh, albeit faster with
help from zsh. Changing scope when changing frames however has to be
done with zsh support.

3.b) Setting $0

3.c) lots of other stuff including...

  display expressions, signal handling, 
  debugger commands:
     debug
     condition
     file
     handle
     history
     pwd
     signal
     tty
     watch

  None of this is rocket science. Should be pretty straight-forward to
  add.

4. WHAT MAY NEED MORE WORK AND SUPPORT FROM ZSH

4.a) stopping points that can be used for breakpoint