The cmd_foo() function is a moral equivalent of 'main' for a Git
subcommand 'git foo', and as such, it is allowed to do many things
that make it unsuitable to be called as a subroutine, including
- call exit(3) to terminate the process;
- allocate resource held and used throughout its lifetime, without
releasing it upon return/exit;
- rely on global variables being initialized at program startup,
and update them as needed, making another clean invocation of the
function impossible.
The call to cmd_diff_index() "git describe" makes has been working
by accident that the function did not call exit(3); it sets a bad
precedent for people to cut and paste.
We could invoke it via the run_command() interface, but the diff
family of commands have helper functions in diff-lib.c that are
meant to be usable as subroutines, and using the latter does not
make the resulting code all that longer. Use it.
Note that there is also an invocation of cmd_name_rev() at the end;
"git describe --contains" massages its command line arguments to be
suitable for "git name-rev" invocation and jumps to it, never to
regain control. This call is left as-is as an exception to the
rule. When we start to allow calling name-rev repeatedly as a
helper function, we would be able to remove this call as well.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public
License version 2 (some parts of it are under different licenses,
compatible with the GPLv2). It was originally written by Linus
Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/
including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
The maintainer frequently sends the "What's cooking" reports that
list the current status of various development topics to the mailing
list. The discussion following them give a good reference for
project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very
first version. He described the tool as "the stupid content tracker"
and the name as (depending on your mood):
random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
"global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
"goddamn idiotic truckload of sh*t": when it breaks
