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
+<<Basic Repository>> commands are needed by people who have a
repository --- that is everybody, because every working tree of
git is a repository.
works alone.
If you work with other people, you will need commands listed in
-<<Individual Developer (Participant)>> section as well.
+the <<Individual Developer (Participant)>> section as well.
-People who play <<Integrator>> role need to learn some more
+People who play the <<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.
+administrators who are responsible for the care and feeding
+of git repositories.
Basic Repository[[Basic Repository]]
------------------------------------
-Everybody uses these commands to feed and care git repositories.
+Everybody uses these commands to maintain 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-fsck-objects[1] to check the repository for errors.
- * gitlink:git-prune[1] to garbage collect crufts in the
- repository.
+ * gitlink:git-prune[1] to remove unused objects in the repository.
* gitlink:git-repack[1] to pack loose objects for efficiency.
$ 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.
+disk space 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
------------
++
+<1> pack all the objects reachable from the refs into one pack,
+then remove the 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
+other people, 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.
Examples
~~~~~~~~
-Extract a tarball and create a working tree and a new repository to keep track of it.::
+Use a tarball as a starting point for a new repository:
+
------------
$ tar zxf frotz.tar.gz
$ 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 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
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)]]
$ 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 log -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.
-<4> look at the changes since last time we checked, only in the
+<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 and merge.
+<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.::
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.
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 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]]
$ 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.
<8> and bundle topic branches still cooking.
<9> backport a critical fix.
<10> create a signed tag.
-<11> make sure I did not accidentally rewound master beyond what I
+<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
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]]
* 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.
+link:howto/update-hook-example.txt[update hook howto] has a good
+example of managing a shared central repository.
Examples
~~~~~~~~
+We assume the following in /etc/services::
++
+------------
+$ grep 9418 /etc/services
+git 9418/tcp # Git Version Control System
+------------
Run git-daemon to serve /pub/scm from inetd.::
+
------------
-$ grep git /etc/inet.conf
+$ grep git /etc/inetd.conf
git stream tcp nowait nobody \
- /usr/bin/git-daemon git-daemon --inetd --syslog --export-all /pub/scm
+ /usr/bin/git-daemon git-daemon --inetd --export-all /pub/scm
------------
+
The actual configuration line should be on one line.
+Run git-daemon to serve /pub/scm from xinetd.::
++
+------------
+$ 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 --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.
+
Give push/pull only access to developers.::
+
------------
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.::
+
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/
<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.