Overview

xmlcmd

xmlcmd is a proof of concept experiment in augmenting standard POSIX commands with superpowers, such as outputting xml.

Sadly it is more sleight of hand than any real magic.

To begin with, a directory which is first on the PATH must be created (e.g. ~/bin). This should not be on the path which whereis uses, so if things go wrong you can always do $(whereis cmd) to execute affected commands.

The idea is to put symlinks to xmlcmd (which is created in the normal python setup.py install installation) into this directory for a number of commands. When these commands are run with an --xml option, the _{cmd} module will be imported from the xmlcmd package and the main() function run with two arguments: the original list of command line arguments (typically corresponding to sys.argv) minus the --xml, and the full path to the 'original' file which would have been run if the --xml option had not been specified.

This is similar to the way busybox works to implement a whole range of UNIX commands from a single binary, by using argv[0] to determine the required action. This allows the relevant logic to be factored out into a single place.

ben$ sudo pip install xmlcmd
...
ben$ ln -s $(which xmlcmd) ~/bin/ls
ben$ ls --xml
<an XMLish representation of a file listing...>

Plans:

  1. Add a few more commands (currently only supports ls and ps)
  2. Put a bunch of actually helpful XML output things into the xmlcmd package to simplify creation of additional command helpers
  3. A more useful xpath command than the perl program of that name on my OS X and Ubuntu installs

Ben Bass 2011