$ git fsck-objects (1) $ git prune $ git count-objects (2) $ git repack (3) $ git prune (4)
GIT suite has over 100 commands, and the manual page for each of them discusses what the command does and how it is used in detail, but until you know what command should be used in order to achieve what you want to do, you cannot tell which manual page to look at, and if you know that already you do not need the manual.
Does that mean you need to know all of them before you can use git? Not at all. Depending on the role you play, the set of commands you need to know is slightly different, but in any case what you need to learn is far smaller than the full set of commands to carry out your day-to-day work. This document is to serve as a cheat-sheet and a set of pointers for people playing various roles.
[Basic Repository] commands are needed by people who has a repository --- that is everybody, because every working tree of git is a repository.
In addition, [Individual Developer (Standalone)] commands are essential for anybody who makes a commit, even for somebody who works alone.
If you work with other people, you will need commands listed in [Individual Developer (Participant)] section as well.
People who play [Integrator] role need to learn some more commands in addition to the above.
[Repository Administration] commands are for system administrators who are responsible to care and feed git repositories to support developers.
Everybody uses these commands to feed and care git repositories.
git-init-db(1) or git-clone(1) to create a new repository.
git-fsck-objects(1) to validate the repository.
git-prune(1) to garbage collect cruft in the repository.
git-repack(1) to pack loose objects for efficiency.
$ git fsck-objects (1) $ git prune $ git count-objects (2) $ git repack (3) $ git prune (4)
running without "—full" is usually cheap and assures the repository health reasonably well.
check how many loose objects there are and how much disk space is wasted by not repacking.
without "-a" repacks incrementally. repacking every 4-5MB of loose objects accumulation may be a good rule of thumb.
after repack, prune removes the duplicate loose objects.
$ git repack -a -d (1) $ git prune
pack all the objects reachable from the refs into one pack and remove unneeded other packs
A standalone individual developer does not exchange patches with other people, and works alone in a single repository, using the following commands.
git-show-branch(1) to see where you are.
git-log(1) to see what happened.
git-whatchanged(1) to find out where things have come from.
git-checkout(1) and git-branch(1) to switch branches.
git-add(1) and git-update-index(1) to manage the index file.
git-diff(1) and git-status(1) to see what you are in the middle of doing.
git-commit(1) to advance the current branch.
git-reset(1) and git-checkout(1) (with pathname parameters) to undo changes.
git-pull(1) with "." as the remote to merge between local branches.
git-rebase(1) to maintain topic branches.
git-tag(1) to mark known point.
$ tar zxf frotz.tar.gz $ cd frotz $ git-init-db $ git add . (1) $ git commit -m 'import of frotz source tree.' $ git tag v2.43 (2)
add everything under the current directory.
make a lightweight, unannotated tag.
$ git checkout -b alsa-audio (1) $ edit/compile/test $ git checkout -- curses/ux_audio_oss.c (2) $ git add curses/ux_audio_alsa.c (3) $ edit/compile/test $ git diff (4) $ git commit -a -s (5) $ edit/compile/test $ git reset --soft HEAD^ (6) $ edit/compile/test $ git diff ORIG_HEAD (7) $ git commit -a -c ORIG_HEAD (8) $ git checkout master (9) $ git pull . alsa-audio (10) $ git log --since='3 days ago' (11) $ git log v2.43.. curses/ (12)
create a new topic branch.
revert your botched changes in "curses/ux_audio_oss.c".
you need to tell git if you added a new file; removal and modification will be caught if you do "commit -a" later.
to see what changes you are committing.
commit everything as you have tested, with your sign-off.
take the last commit back, keeping what is in the working tree.
look at the changes since the premature commit we took back.
redo the commit undone in the previous step, using the message you originally wrote.
switch to the master branch.
merge a topic branch into your master branch
review commit logs; other forms to limit output can be combined and include —max-count=10 (show 10 commits), —until=2005-12-10.
view only the changes that touch what's in curses/ directory, since v2.43 tag.
A developer working as a participant in a group project needs to learn how to communicate with others, and uses these commands in addition to the ones needed by a standalone developer.
git-clone(1) from the upstream to prime your local repository.
git-pull(1) and git-fetch(1) from "origin" to keep up-to-date with the upstream.
git-push(1) to shared repository, if you adopt CVS style shared repository workflow.
git-format-patch(1) to prepare e-mail submission, if you adopt Linux kernel-style public forum workflow.
$ git clone git://git.kernel.org/pub/scm/.../torvalds/linux-2.6 my2.6 $ cd my2.6 $ edit/compile/test; git commit -a -s (1) $ git format-patch origin (2) $ git pull (3) $ git whatchanged -p ORIG_HEAD.. arch/i386 include/asm-i386 (4) $ git pull git://git.kernel.org/pub/.../jgarzik/libata-dev.git ALL (5) $ git reset --hard ORIG_HEAD (6) $ git prune (7) $ git fetch --tags (8)
repeat as needed.
extract patches from your branch for e-mail submission.
"pull" fetches from "origin" by default and merges into the current branch.
immediately after pulling, look at the changes done upstream since last time we checked, only in the area we are interested in.
fetch from a specific branch from a specific repository and merge.
revert the pull.
garbage collect leftover objects from reverted pull.
from time to time, obtain official tags from the "origin" and store them under .git/refs/tags/.
satellite$ git clone mothership:frotz/.git frotz (1) satellite$ cd frotz satellite$ cat .git/remotes/origin (2) URL: mothership:frotz/.git Pull: master:origin satellite$ echo 'Push: master:satellite' >>.git/remotes/origin (3) satellite$ edit/compile/test/commit satellite$ git push origin (4) mothership$ cd frotz mothership$ git checkout master mothership$ git pull . satellite (5)
mothership machine has a frotz repository under your home directory; clone from it to start a repository on the satellite machine.
clone creates this file by default. It arranges "git pull" to fetch and store the master branch head of mothership machine to local "origin" branch.
arrange "git push" to push local "master" branch to "satellite" branch of the mothership machine.
push will stash our work away on "satellite" branch on the mothership machine. You could use this as a back-up method.
on mothership machine, merge the work done on the satellite machine into the master branch.
$ git checkout -b private2.6.14 v2.6.14 (1) $ edit/compile/test; git commit -a $ git checkout master $ git format-patch -k -m --stdout v2.6.14..private2.6.14 | git am -3 -k (2)
create a private branch based on a well known (but somewhat behind) tag.
forward port all changes in private2.6.14 branch to master branch without a formal "merging".
A fairly central person acting as the integrator in a group project receives changes made by others, reviews and integrates them and publishes the result for others to use, using these commands in addition to the ones needed by participants.
git-am(1) to apply patches e-mailed in from your contributors.
git-pull(1) to merge from your trusted lieutenants.
git-format-patch(1) to prepare and send suggested alternative to contributors.
git-revert(1) to undo botched commits.
git-push(1) to publish the bleeding edge.
$ git status (1) $ git show-branch (2) $ mailx (3) & s 2 3 4 5 ./+to-apply & s 7 8 ./+hold-linus & q $ git checkout master $ git am -3 -i -s -u ./+to-apply (4) $ compile/test $ git checkout -b hold/linus && git am -3 -i -s -u ./+hold-linus (5) $ git checkout topic/one && git rebase master (6) $ git checkout pu && git reset --hard master (7) $ git pull . topic/one topic/two && git pull . hold/linus (8) $ git checkout maint $ git cherry-pick master~4 (9) $ compile/test $ git tag -s -m 'GIT 0.99.9x' v0.99.9x (10) $ git fetch ko && git show-branch master maint 'tags/ko-*' (11) $ git push ko (12) $ git push ko v0.99.9x (13)
see what I was in the middle of doing, if any.
see what topic branches I have and think about how ready they are.
read mails, save ones that are applicable, and save others that are not quite ready.
apply them, interactively, with my sign-offs.
create topic branch as needed and apply, again with my sign-offs.
rebase internal topic branch that has not been merged to the master, nor exposed as a part of a stable branch.
restart "pu" every time from the master.
and bundle topic branches still cooking.
backport a critical fix.
create a signed tag.
make sure I did not accidentally rewind master beyond what I already pushed out. "ko" shorthand points at the repository I have at kernel.org, and looks like this:
$ cat .git/remotes/ko URL: kernel.org:/pub/scm/git/git.git Pull: master:refs/tags/ko-master Pull: maint:refs/tags/ko-maint Push: master Push: +pu Push: maint
In the output from "git show-branch", "master" should have everything "ko-master" has.
push out the bleeding edge.
push the tag out, too.
A repository administrator uses the following tools to set up and maintain access to the repository by developers.
git-daemon(1) to allow anonymous download from repository.
git-shell(1) can be used as a restricted login shell for shared central repository users.
update hook howto has a good example of managing a shared central repository.
$ grep git /etc/inetd.conf git stream tcp nowait nobody \ /usr/bin/git-daemon git-daemon --inetd --syslog --export-all /pub/scm
The actual configuration line should be on one line.
$ cat /etc/xinetd.d/git-daemon
# default: off
# description: The git server offers access to git repositories
service git
{
disable = no
type = UNLISTED
port = 9418
socket_type = stream
wait = no
user = nobody
server = /usr/bin/git-daemon
server_args = --inetd --syslog --export-all --base-path=/pub/scm
log_on_failure += USERID
}
Check your xinetd(8) documentation and setup, this is from a Fedora system. Others might be different.
$ grep git /etc/passwd (1) alice:x:1000:1000::/home/alice:/usr/bin/git-shell bob:x:1001:1001::/home/bob:/usr/bin/git-shell cindy:x:1002:1002::/home/cindy:/usr/bin/git-shell david:x:1003:1003::/home/david:/usr/bin/git-shell $ grep git /etc/shells (2) /usr/bin/git-shell
log-in shell is set to /usr/bin/git-shell, which does not allow anything but "git push" and "git pull". The users should get an ssh access to the machine.
in many distributions /etc/shells needs to list what is used as the login shell.
$ grep git /etc/group (1) git:x:9418:alice,bob,cindy,david $ cd /home/devo.git $ ls -l (2) lrwxrwxrwx 1 david git 17 Dec 4 22:40 HEAD -> refs/heads/master drwxrwsr-x 2 david git 4096 Dec 4 22:40 branches -rw-rw-r-- 1 david git 84 Dec 4 22:40 config -rw-rw-r-- 1 david git 58 Dec 4 22:40 description drwxrwsr-x 2 david git 4096 Dec 4 22:40 hooks -rw-rw-r-- 1 david git 37504 Dec 4 22:40 index drwxrwsr-x 2 david git 4096 Dec 4 22:40 info drwxrwsr-x 4 david git 4096 Dec 4 22:40 objects drwxrwsr-x 4 david git 4096 Nov 7 14:58 refs drwxrwsr-x 2 david git 4096 Dec 4 22:40 remotes $ ls -l hooks/update (3) -r-xr-xr-x 1 david git 3536 Dec 4 22:40 update $ cat info/allowed-users (4) refs/heads/master alice\|cindy refs/heads/doc-update bob refs/tags/v[0-9]* david
place the developers into the same git group.
and make the shared repository writable by the group.
use update-hook example by Carl from Documentation/howto/ for branch policy control.
alice and cindy can push into master, only bob can push into doc-update. david is the release manager and is the only person who can create and push version tags.
dev$ git update-server-info (1) dev$ ftp user@isp.example.com (2) ftp> cp -r .git /home/user/myproject.git
make sure your info/refs and objects/info/packs are up-to-date
upload to public HTTP server hosted by your ISP.