Coding Style Guide
==================

Introduction
------------
This document attempts to explain the basic styles and patterns that
are used in the bash completion.  New code should try to conform to
these standards so that it is as easy to maintain as existing code.
Of course every rule has an exception, but it's important to know
the rules nonetheless!

This is particularly directed at people new to the bash completion
codebase, who are in the process of getting their code reviewed.
Before getting a review, please read over this document and make
sure your code conforms to the recommendations here.

Indentation
-----------
Indent step should be 4 spaces, no tabs.

Globbing in case labels
-----------------------

Avoid "fancy" globbing in case labels, just use traditional style when
possible.  For example, do "--foo|--bar)" instead of "--@(foo|bar))".
Rationale: the former is easier to read, often easier to grep, and
doesn't confuse editors as bad as the latter, and is concise enough.

[[ ]] vs [ ]
----------------

Use [[ ]] instead of [ ] when testing multiple conditions. [ ] is fine
for single conditions where the syntax works.  Rationale: [[ ]] has
short circuit behavior within one test containing multiple conditions
separated by && or ||, while [ ] with -a or -o does not.  Thus it can
be more efficient in some cases and may reduce need for nesting
conditions, and it's cleaner to write for example [[ ... && ... ]]
than [ ... ] && [ ... ], and in general [[ ]] has more features.

Line wrapping
-------------

Try to wrap lines at 79 characters. Never go past this limit, unless
you absolutely need to (example: a long sed regular expression, or the
like). This also holds true for the documentation and the testsuite.
Other files, like ChangeLog, or COPYING, are exempt from this rule.

$(...) vs `...`
---------------

When you need to do some code substitution in your completion script,
you *MUST* use the $(...) construct, rather than the `...`. The former
is preferable because anyone, with any keyboard layout, is able to
type it. Backticks aren't always available, without doing strange
key combinations.

/////////////////////////////////////////
case/esac vs if
---------------

quoting
-------

awk vs cut for simple cases
---------------------------

variable and function naming
----------------------------

/////////////////////////////////////////