The first news is that I have just released Bill 0.2, which introduces the following changes:

• Change license to the new GPLv3.
• Modules have now a .bash suffix instead of .bsh
• Compatibility fixes, so it now works better with Bash 3.1
• Better handling of comment lines and nicer error handler in the text/config module.
• Some other minor bug fixes.
• New modules: twiki/ext, text/bte, data/time, text/log

Last but not least, as my colleagues are saying (e.g. Mario, Joaquim, Javier M., Sergio) in their latest posts, we had a very nice inauguration party at our brand new office. I think they have already written what needs to be said, so I will only add that I think that it worths having some inconveniences (as we had!) during the switch from one office to another. Everyone did a good job to get everything in place. Congrats!

I hope to start blogging again regularly. I have some ideas pending to be written, now the problem is to find some spare time slots to expand them

Bash 3.2 has died… long live Bash 3.2!

• Better test suite and fixes for the data/hash module
• Fix bug which prevented serving content from a non-default Billet
• Allow for manually setting the server name in billetd
• New config_ini_get_chained function in module text/config
• The butt utility now accepts file names as arguments, so you can choose which unit tests to run, instead of waiting for the full lot to finish
• Speed improvements when decoding MIME data in module text/mime

Last, but not least, some polish was applied to the documentation and code style, and autogenerated files (i.e. HTML documentation) was removed from the GIT repository.

And now, go and get some packages

Enjoy!

the_world_is_flat=true
# ...do something interesting...
if $the_world_is_flat ; then
  echo 'Be carefule not to fall off!'
fi

This example may look familiar to some of my readers, because in fact it is taken from the Bill tutorial. Some modules included in Bill use this kind of syntax extensively. Some care must be taken, because we are directly executing the contents of a variable in the if clause, so you would not better use this with values entered by the user, but I find very convenient to directly expand and evaluate true and false from variables when they come from “trusted” code.

I learned this trick several years ago from my friend Andrés when we were working together. I do not know when did he learn this syntax, but I am sure that the thing is not as new as it sounds.

Oops, almost forgot: have a nice 2009!

In short, Bill is a solution for creating high-quality Bash code using reusable components. As GNU Bash is its only dependency, it can be run nearly everywhere—even on resource-limited systems!

Origins and motivation

Sometimes one wants to spit out some code to glue together a set of already available tools and quickly solve a problem by combining their strengths. That is okay, and using a shell script is probably the best solution, until annoyances arise:

1. Portions of boilerplate code is repeated one script after another. Bill addresses this problem by providing a way of creating and reusing modules, and by providing a set of standard ones. It comes with batteries included.
2. The script will eventually grow; and it will become a nightmare to debug and maintain. Bill includes tools for testing and documenting the code.
3. Some ideas are complicated to achieve in shell code, and usually implementing them can be tricky. Bill already does the tricks for you, so you can focus on the actual code.

Thus, Bill was born with three main goals in mind: having as little dependencies as possible, easing development of complex applications, and serving as a playground for advanced usage of Bash. While I was making progress with the code, we had the ideas of running simple web applications coded in shell scripts and having unit tests and added them on the go.

Trying it out

If you use a dpkg-based distribution (Ubuntu, Debian), just grab the .deb package and install it by running dpkg -i bill_0.1-1_all.deb. Otherwise you can download the source tarball and unpack it with tar -xfj bill-0.1.tar.bz2. You can run Bill without installing by adding the bill-0.1/scripts/ directory to your PATH environment variable.

Once you have your copy you are ready to read the tutorial. I will give you only an appetizer here:

$ bill
(bill) echo "Hello, Bill!"
Hello, Bill!
(bill)

This is all for today, but expect more news related to Bill in the future. For the intrepid in you, you can check out the code repository at Gitorious, the code is under the GPL v2 license. I hope you enjoy this initial release as much as I did while preparing it.

Have a lot of fun…