Coding Style Conventions
========================

Coding style guidelines are about reducing the number of unnecessary
reformatting patches and making things easier for developers to work together.

You don't have to like them or even agree with them, but once put in place we
all have to abide by them (or vote to change them).  However, coding style
should never outweigh coding itself and so the guidelines described here are
hopefully easy enough to follow as they are very common and supported by tools
and editors.

The basic style for C code is the Linux kernel coding style [1] with one
excecption, we use 4 spaces instead of tabs. This closely matches what most
libssh developers use already anyways, with a few exceptions as mentioned
below.

To shorthen this here are the highlights:

* Maximum line width is 80 characters

  The reason is not about people with low-res screens but rather sticking
  to 80 columns prevents you from easily nesting more than one level of
  if statements or other code blocks.

* Use 4 spaces to indent

* No trailing whitespaces

* Follow the K&R guidelines.  We won't go through all of them here. Do you
  have a copy of "The C Programming Language" anyways right?

Editors
========

VIM
----

set ts=4 sw=4 et cindent

For Vim, the following settings in $HOME/.vimrc will also deal with
displaying trailing whitespace:

    if has("syntax") && (&t_Co > 2 || has("gui_running"))
        syntax on
        function! ActivateInvisibleCharIndicator()
            syntax match TrailingSpace "[ \t]\+$" display containedin=ALL
            highlight TrailingSpace ctermbg=Red
        endf
        autocmd BufNewFile,BufRead * call ActivateInvisibleCharIndicator()
    endif
    " Show tabs, trailing whitespace, and continued lines visually
    set list listchars=tab:»·,trail:·,extends:…

    " highlight overly long lines same as TODOs.
    set textwidth=80
    autocmd BufNewFile,BufRead *.c,*.h exec 'match Todo /\%>' . &textwidth . 'v.\+/'

[1] https://www.kernel.org/doc/Documentation/CodingStyle