Hacking on man-db
=================

man-db is not a large or particularly complicated project, but there is
still plenty for an interested developer to contribute. Here's a very brief
guide on how to get started.


Directory layout
----------------

The source tree looks something like this, ignoring some directories added
by autoconf, automake, gettext, and gnulib:

  docs/
    Assorted documentation.
  man/
    Man pages for man-db's programs.
  manual/
    The man-db manual, written in troff.
  include/
    Header files used throughout the package.
  lib/
    Basic library files, some of which supplement inadequate C libraries on
    various systems and some of which implement utility functions used
    throughout the package.
  libdb/
    The database access library. Code outside this directory should not know
    about specific back-end database implementations.
  src/
    Source code to the man-db programs themselves.
  tools/
    Miscellaneous add-on scripts.
  po/
    Translations.


Coding style
------------

Each indent is a single tab. Brace style is K&R. Each function name is
separated from the following opening parenthesis by a single space. (All
this is almost certainly controversial somewhere, but it's as close as
you'll get to a prevailing style here.)

Keep all code within 80 columns (counting tabs as 8). This can sometimes be
a little tight with the deep indent; think of it as a useful discipline to
stop indentation levels getting out of hand. :-) (This rule is currently
broken for argp option declarations, for the sake of other kinds of
readability. This may change.)

If you're editing existing code and it differs from any of the above, stick
with whatever the existing code does. Likewise, if in doubt, find similar
code and use its style. Maintaining a consistent style is important for
general readability, and is more important than any individual point. It's
also the easiest way to avoid long and tedious debates about "correct"
style.


Facilities and portability
--------------------------

man-db uses Gnulib to provide portability support and utility functions
common to many GNU packages (although man-db is not itself a GNU package),
while the lib/ directory provides some other utility functions specific to
man-db. Please make use of these facilities where available. In particular,
there are various functions beginning with 'x' which check the return values
from the system's memory allocation calls, which you should use instead of
their non-'x' siblings.

appendstr() provides manageable string concatenation. Use it where
appropriate. Remember to terminate its argument list with a NULL. In many
cases, xasprintf() from Gnulib may be more readable.

If you're calling any of the is*() or to*() functions in <ctype.h>, please
do so via the CTYPE() macro in include/manconfig.h to ensure that the
argument type is correct.

You may assume C89 (e.g. no need to support K&R-style function definitions),
but please do not assume C99 (e.g. do not use nested functions or //
comments).  However, it's OK to use C99 runtime facilities that are provided
by Gnulib, such as <stdbool.h>.


Testing
-------

There is a small test suite in src/tests/, as well as basic tests in man/ to
ensure that man-db's own manual pages format without errors. Tests for new
bug fixes are not *required*, but are generally a good idea.

Various test library facilities are available in src/tests/testlib.sh. Feel
free to extend this as necessary.


Things to do
------------

docs/TODO has a number of outstanding projects. Things near the bottom are
usually more detailed and accurate.

The Debian bug tracking system has a number of outstanding reports on man-db
at <https://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=man-db;ordering=upstream>.

Much of the work needed on man-db is for maintainability. Patches that take
difficult-to-understand code with hairy memory allocation and replace it
with clean, obvious, and reliable code are most welcome, especially if they
introduce new abstractions which are of more general use. The replacement of
splitline() with the page_description interface is a good example of this.

Work on porting to platforms other than GNU/Linux is welcome. It's been a
while since serious effort in that direction has been invested in man-db.
Most of the code should be quite portable, but the occasional teething
problem would not be a surprise.


Sending patches
---------------

Please send patches in unified diff format (use 'git diff', or GNU diff with
the -u option) to man-db-devel@nongnu.org. See
https://lists.nongnu.org/mailman/listinfo/man-db-devel for subscription
instructions.


Revision control
----------------

man-db is revision-controlled using git (https://git-scm.com/). The archive
may be fetched from here using 'git clone':

  https://git.savannah.gnu.org/git/man-db.git

To browse changes or source code in a web browser, use this URL instead:

  https://git.savannah.gnu.org/cgit/man-db.git

Members of the man-db project on Savannah can commit directly by pushing to
this URL:

  ssh://git.sv.gnu.org/srv/git/man-db.git

Otherwise, since git is a distributed revision control system, you are of
course free to make and publish branches which can then be merged into the
main tree. See the git documentation for further details.

Generated files should be added to .gitignore and should not be committed to
revision control.


Release process
---------------

1. Update the AC_INIT version number in configure.ac to "x.y.z-pre1". Commit
   and tag.

2. Run ./release.sh to produce a preliminary tarball for translators. This
   doesn't have to be particularly well-tested or even compile; it's only
   there to provide context for po/man-db.pot. Send this to the Translation
   Project robot.

3. Wait a couple of weeks for a reasonable number of translation updates to
   arrive. During this time, test until your eyeballs fall out, but try to
   avoid changing any translated messages.

4. Ensure that NEWS and docs/man-db.lsm are up to date. Commit.

5. Update the AC_INIT version number and 'date' in configure.ac, but don't
   commit yet.

6. Run ./release.sh, which will spit out a tarball. Test it.

7. Commit the changes from step 5.

8. Tag everything.

9. Run ./release.sh. This is the distribution tarball; test it as thoroughly
   as you can.

10. Upload the tarball to Savannah.

11. Announce to wherever seems appropriate.
