| Everyday GIT With 20 Commands Or So |
| =================================== |
| |
| 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. |
| |
| |
| Basic Repository[[Basic Repository]] |
| ------------------------------------ |
| |
| Everybody uses these commands to feed and care git repositories. |
| |
| * gitlink:git-init-db[1] or gitlink:git-clone[1] to create a |
| new repository. |
| |
| * gitlink:git-fsck-objects[1] to validate the repository. |
| |
| * gitlink:git-prune[1] to garbage collect crufts in the |
| repository. |
| |
| * gitlink:git-repack[1] to pack loose objects for efficiency. |
| |
| Examples |
| ~~~~~~~~ |
| |
| Check health and remove cruft.:: |
| + |
| ------------ |
| $ git fsck-objects <1> |
| $ git prune |
| $ git count-objects <2> |
| $ git repack <3> |
| $ git prune <4> |
| |
| <1> running without "--full" is usually cheap and assures the |
| repository health reasonably well. |
| <2> check how many loose objects there are and how much |
| diskspace is wasted by not repacking. |
| <3> without "-a" repacks incrementally. repacking every 4-5MB |
| of loose objects accumulation may be a good rule of thumb. |
| <4> after repack, prune removes the duplicate loose objects. |
| ------------ |
| |
| Repack a small project into single pack.:: |
| + |
| ------------ |
| $ git repack -a -d <1> |
| $ git prune |
| |
| <1> pack all the objects reachable from the refs into one pack |
| and remove unneeded other packs |
| ------------ |
| |
| |
| Individual Developer (Standalone)[[Individual Developer (Standalone)]] |
| ---------------------------------------------------------------------- |
| |
| A standalone individual developer does not exchange patches with |
| other poeple, and works alone in a single repository, using the |
| following commands. |
| |
| * gitlink:git-show-branch[1] to see where you are. |
| |
| * gitlink:git-log[1] to see what happened. |
| |
| * gitlink:git-whatchanged[1] to find out where things have |
| come from. |
| |
| * gitlink:git-checkout[1] and gitlink:git-branch[1] to switch |
| branches. |
| |
| * gitlink:git-add[1] and gitlink:git-update-index[1] to manage |
| the index file. |
| |
| * gitlink:git-diff[1] and gitlink:git-status[1] to see what |
| you are in the middle of doing. |
| |
| * gitlink:git-commit[1] to advance the current branch. |
| |
| * gitlink:git-reset[1] and gitlink:git-checkout[1] (with |
| pathname parameters) to undo changes. |
| |
| * gitlink:git-pull[1] with "." as the remote to merge between |
| local branches. |
| |
| * gitlink:git-rebase[1] to maintain topic branches. |
| |
| * gitlink:git-tag[1] to mark known point. |
| |
| Examples |
| ~~~~~~~~ |
| |
| Extract a tarball and create a working tree and a new repository to keep track of it.:: |
| + |
| ------------ |
| $ 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> |
| |
| <1> add everything under the current directory. |
| <2> make a lightweight, unannotated tag. |
| ------------ |
| |
| Create a topic branch and develop.:: |
| + |
| ------------ |
| $ 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> |
| |
| <1> create a new topic branch. |
| <2> revert your botched changes in "curses/ux_audio_oss.c". |
| <3> you need to tell git if you added a new file; removal and |
| modification will be caught if you do "commit -a" later. |
| <4> to see what changes you are committing. |
| <5> commit everything as you have tested, with your sign-off. |
| <6> take the last commit back, keeping what is in the working tree. |
| <7> look at the changes since the premature commit we took back. |
| <8> redo the commit undone in the previous step, using the message |
| you originally wrote. |
| <9> switch to the master branch. |
| <10> merge a topic branch into your master branch |
| <11> review commit logs; other forms to limit output can be |
| combined and include --max-count=10 (show 10 commits), --until='2005-12-10'. |
| <12> view only the changes that touch what's in curses/ |
| directory, since v2.43 tag. |
| ------------ |
| |
| |
| Individual Developer (Participant)[[Individual Developer (Participant)]] |
| ------------------------------------------------------------------------ |
| |
| 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. |
| |
| * gitlink:git-clone[1] from the upstream to prime your local |
| repository. |
| |
| * gitlink:git-pull[1] and gitlink:git-fetch[1] from "origin" |
| to keep up-to-date with the upstream. |
| |
| * gitlink:git-push[1] to shared repository, if you adopt CVS |
| style shared repository workflow. |
| |
| * gitlink:git-format-patch[1] to prepare e-mail submission, if |
| you adopt Linux kernel-style public forum workflow. |
| |
| Examples |
| ~~~~~~~~ |
| |
| Clone the upstream and work on it. Feed changes to upstream.:: |
| + |
| ------------ |
| $ 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> |
| |
| <1> repeat as needed. |
| <2> extract patches from your branch for e-mail submission. |
| <3> "pull" fetches from "origin" by default and merges into the |
| current branch. |
| <4> immediately after pulling, look at the changes done upstream |
| since last time we checked, only in the |
| area we are interested in. |
| <5> fetch from a specific branch from a specific repository and merge. |
| <6> revert the pull. |
| <7> garbage collect leftover objects from reverted pull. |
| <8> from time to time, obtain official tags from the "origin" |
| and store them under .git/refs/tags/. |
| ------------ |
| |
| |
| Push into another repository.:: |
| + |
| ------------ |
| 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> |
| |
| <1> mothership machine has a frotz repository under your home |
| directory; clone from it to start a repository on the satellite |
| machine. |
| <2> 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. |
| <3> arrange "git push" to push local "master" branch to |
| "satellite" branch of the mothership machine. |
| <4> push will stash our work away on "satellite" branch on the |
| mothership machine. You could use this as a back-up method. |
| <5> on mothership machine, merge the work done on the satellite |
| machine into the master branch. |
| ------------ |
| |
| Branch off of a specific tag.:: |
| + |
| ------------ |
| $ 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> |
| |
| <1> create a private branch based on a well known (but somewhat behind) |
| tag. |
| <2> forward port all changes in private2.6.14 branch to master branch |
| without a formal "merging". |
| ------------ |
| |
| |
| Integrator[[Integrator]] |
| ------------------------ |
| |
| 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. |
| |
| * gitlink:git-am[1] to apply patches e-mailed in from your |
| contributors. |
| |
| * gitlink:git-pull[1] to merge from your trusted lieutenants. |
| |
| * gitlink:git-format-patch[1] to prepare and send suggested |
| alternative to contributors. |
| |
| * gitlink:git-revert[1] to undo botched commits. |
| |
| * gitlink:git-push[1] to publish the bleeding edge. |
| |
| |
| Examples |
| ~~~~~~~~ |
| |
| My typical GIT day.:: |
| + |
| ------------ |
| $ 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> |
| |
| <1> see what I was in the middle of doing, if any. |
| <2> see what topic branches I have and think about how ready |
| they are. |
| <3> read mails, save ones that are applicable, and save others |
| that are not quite ready. |
| <4> apply them, interactively, with my sign-offs. |
| <5> create topic branch as needed and apply, again with my |
| sign-offs. |
| <6> rebase internal topic branch that has not been merged to the |
| master, nor exposed as a part of a stable branch. |
| <7> restart "pu" every time from the master. |
| <8> and bundle topic branches still cooking. |
| <9> backport a critical fix. |
| <10> create a signed tag. |
| <11> 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. |
| <12> push out the bleeding edge. |
| <13> push the tag out, too. |
| ------------ |
| |
| |
| Repository Administration[[Repository Administration]] |
| ------------------------------------------------------ |
| |
| A repository administrator uses the following tools to set up |
| and maintain access to the repository by developers. |
| |
| * gitlink:git-daemon[1] to allow anonymous download from |
| repository. |
| |
| * gitlink:git-shell[1] can be used as a 'restricted login shell' |
| for shared central repository users. |
| |
| link:howto/update-hook-example.txt[update hook howto] has a good |
| example of managing a shared central repository. |
| |
| |
| Examples |
| ~~~~~~~~ |
| |
| Run git-daemon to serve /pub/scm from inetd.:: |
| + |
| ------------ |
| $ grep git /etc/inet.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. |
| |
| Give push/pull only access to developers.:: |
| + |
| ------------ |
| $ 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 |
| |
| <1> 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. |
| <2> in many distributions /etc/shells needs to list what is used |
| as the login shell. |
| ------------ |
| |
| CVS-style shared repository.:: |
| + |
| ------------ |
| $ 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 |
| |
| <1> place the developers into the same git group. |
| <2> and make the shared repository writable by the group. |
| <3> use update-hook example by Carl from Documentation/howto/ |
| for branch policy control. |
| <4> 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. |
| ------------ |
| |
| HTTP server to support dumb protocol transfer.:: |
| + |
| ------------ |
| dev$ git update-server-info <1> |
| dev$ ftp user@isp.example.com <2> |
| ftp> cp -r .git /home/user/myproject.git |
| |
| <1> make sure your info/refs and objects/info/packs are up-to-date |
| <2> upload to public HTTP server hosted by your ISP. |
| ------------ |