= sysexits

project:: https://bitbucket.org/ged/sysexits github:: https://github.com/ged/sysexits docs:: http://deveiate.org/code/sysexits

== Description

Have you ever wanted to call exit() with an error condition, but weren't sure what exit status to use? No? Maybe it's just me, then.

Anyway, I was reading manpages late one evening before retiring to bed in my palatial estate in rural Oregon, and I stumbled across sysexits(3). Much to my chagrin, I couldn't find a +sysexits+ for Ruby! Well, for the other 2 people that actually care about style(9) as it applies to Ruby code, now there is one!

Sysexits is a completely awesome collection of human-readable constants for the standard (BSDish) exit codes, used as arguments to +exit+ to indicate a specific error condition to the parent process.

It's so fantastically fabulous that you'll want to fork it right away to avoid being thought of as that guy that's still using Webrick for his blog. I mean, exit(1) is so passé! This is like the 14-point font of Systems Programming.

Like the C header file from which this was derived (I mean forked, naturally), error numbers begin at Sysexits::EX__BASE (which is way more cool than plain old +64+) to reduce the possibility of clashing with other exit statuses that other programs may already return.

The codes are available in two forms: as constants which can be imported into your own namespace via include Sysexits, or as Sysexits::STATUS_CODES, a Hash keyed by Symbols derived from the constant names.

Allow me to demonstrate. First, the old way:

exit( 69 )

Whaaa...? Is that a euphemism? What's going on? See how unattractive and... well, 1970 that is? We're not changing vaccuum tubes here, people, we're building a totally-awesome future in the Cloud™!

include Sysexits
exit EX_UNAVAILABLE

Okay, at least this is readable to people who have used fork() more than twice, but you could do so much better!

include Sysexits
exit :unavailable

Holy Toledo! It's like we're writing Ruby, but our own made-up dialect in which variable++ is possible! Well, okay, it's not quite that cool. But it does look more Rubyish. And no monkeys were patched in the filming of this episode! All the simpletons still exiting with icky numbers can still continue blithely along, none the wiser.

== Caveats

At some point, Apple started including their own +sysexits+ library in +vendor_ruby+, so to load the gem version on a MacOS X 10.7+ box, you need to do:

gem 'sysexits'
require 'sysexits'

It's a bit ugly, but there isn't a whole lot I can do about it. Sorry.

== Contributing

You can clone the source with Mercurial, submit bug reports, suggestions, etc., via the project page:

https://bitbucket.org/ged/sysexits

Or if you prefer Git, you can clone the source via its Github mirror:

https://github.com/ged/sysexits

After checking out the source, run:

$ rake newb

This task will install any missing dependencies, run the tests/specs, and generate the RDoc.

You can read more super-exited pointless marketing at:

http://deveiate.org/sysexits.html

Or maybe not.

== License

Copyright (c) 2010-2012, Michael Granger All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

• Neither the name of the author/s, nor the names of the project's contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.