88df3ffc28d0de34c73b34f8dcafc682fe4a68cd
   1Everyday GIT With 20 Commands Or So
   2===================================
   3
   4GIT suite has over 100 commands, and the manual page for each of
   5them discusses what the command does and how it is used in
   6detail, but until you know what command should be used in order
   7to achieve what you want to do, you cannot tell which manual
   8page to look at, and if you know that already you do not need
   9the manual.
  10
  11Does that mean you need to know all of them before you can use
  12git?  Not at all.  Depending on the role you play, the set of
  13commands you need to know is slightly different, but in any case
  14what you need to learn is far smaller than the full set of
  15commands to carry out your day-to-day work.  This document is to
  16serve as a cheat-sheet and a set of pointers for people playing
  17various roles.
  18
  19<<Basic Repository>> commands are needed by people who has a
  20repository --- that is everybody, because every working tree of
  21git is a repository.
  22
  23In addition, <<Individual Developer (Standalone)>> commands are
  24essential for anybody who makes a commit, even for somebody who
  25works alone.
  26
  27If you work with other people, you will need commands listed in
  28<<Individual Developer (Participant)>> section as well.
  29
  30People who play <<Integrator>> role need to learn some more
  31commands in addition to the above.
  32
  33<<Repository Administration>> commands are for system
  34administrators who are responsible to care and feed git
  35repositories to support developers.
  36
  37
  38Basic Repository[[Basic Repository]]
  39------------------------------------
  40
  41Everybody uses these commands to feed and care git repositories.
  42
  43  * gitlink:git-init-db[1] or gitlink:git-clone[1] to create a
  44    new repository.
  45
  46  * gitlink:git-fsck-objects[1] to validate the repository.
  47
  48  * gitlink:git-prune[1] to garbage collect crufts in the
  49    repository.
  50
  51  * gitlink:git-repack[1] to pack loose objects for efficiency.
  52
  53Individual Developer (Standalone)[[Individual Developer (Standalone)]]
  54----------------------------------------------------------------------
  55
  56A standalone individual developer does not exchange patches with
  57other poeple, and works alone in a single repository, using the
  58following commands.
  59
  60  * gitlink:git-show-branch[1] to see where you are.
  61
  62  * gitlink:git-log[1] to see what happened.
  63
  64  * gitlink:git-whatchanged[1] to find out where things have
  65    come from.
  66
  67  * gitlink:git-checkout[1] and gitlink:git-branch[1] to switch
  68    branches.
  69
  70  * gitlink:git-add[1] and gitlink:git-update-index[1] to manage
  71    the index file.
  72
  73  * gitlink:git-diff[1] and gitlink:git-status[1] to see what
  74    you are in the middle of doing.
  75
  76  * gitlink:git-commit[1] to advance the current branch.
  77
  78  * gitlink:git-reset[1] and gitlink:git-checkout[1] (with
  79    pathname parameters) to undo changes.
  80
  81  * gitlink:git-pull[1] with "." as the remote to merge between
  82    local branches.
  83
  84  * gitlink:git-rebase[1] to maintain topic branches.
  85
  86  * gitlink:git-tag[1] to mark known point.
  87
  88Examples
  89~~~~~~~~
  90
  91* Extract a tarball and create a working tree and a new repository to keep track of it.
  92------------
  93$ tar zxf frotz.tar.gz
  94$ cd frotz
  95$ git-init-db
  96$ git add . <1>
  97$ git commit -m 'import of frotz source tree.'
  98$ git tag v2.43 <2>
  99
 100<1> add everything under the current directory.
 101<2> make a lightweight, unannotated tag.
 102------------
 103
 104* Create a topic branch and develop
 105------------
 106$ git checkout -b alsa-audio <1>
 107$ edit/compile/test
 108$ git checkout -- curses/ux_audio_oss.c <2>
 109$ git add curses/ux_audio_alsa.c <3>
 110$ edit/compile/test
 111$ git diff <4>
 112$ git commit -a -s <5>
 113$ edit/compile/test
 114$ git reset --soft HEAD^ <6>
 115$ edit/compile/test
 116$ git diff ORIG_HEAD <7>
 117$ git commit -a -c ORIG_HEAD <8>
 118$ git checkout master <9>
 119$ git pull . alsa-audio <10>
 120$ git log --since='3 days ago' <11>
 121$ git log v2.43.. curses/ <12>
 122
 123<1> create a new topic branch.
 124<2> revert your botched changes in "curses/ux_audio_oss.c".
 125<3> you need to tell git if you added a new file; removal and
 126modification will be caught if you do "commit -a" later.
 127<4> to see what changes you are committing.
 128<5> commit everything as you have tested, with your sign-off.
 129<6> take the last commit back, keeping what is in the working tree.
 130<7> look at the changes since the premature commit we took back.
 131<8> redo the commit undone in the previous step, using the message
 132you originally wrote.
 133<9> switch to the master branch.
 134<10> merge a topic branch into your master branch
 135<11> or --since='aug 1', --max-count=10
 136<12> view only the changes that touch what's in curses/
 137directory, since v2.43 tag.
 138------------
 139
 140
 141Individual Developer (Participant)[[Individual Developer (Participant)]]
 142------------------------------------------------------------------------
 143
 144A developer working as a participant in a group project needs to
 145learn how to communicate with others, and uses these commands in
 146addition to the ones needed by a standalone developer.
 147
 148  * gitlink:git-pull[1] from "origin" to keep up-to-date with
 149    the upstream.
 150
 151  * gitlink:git-push[1] to shared repository if you adopt CVS
 152    style shared repository workflow.
 153
 154  * gitlink:git-format-patch[1] to prepare e-mail submission, if
 155    you adopt Linux kernel-style public forum workflow.
 156
 157
 158Examples
 159~~~~~~~~
 160
 161* Clone the upstream and work on it.  Feed changes to upstream.
 162------------
 163$ git clone git://git.kernel.org/pub/scm/.../torvalds/linux-2.6 my2.6
 164$ cd my2.6
 165$ edit/compile/test; git commit -a -s <1>
 166$ git format-patch master <2>
 167$ git pull <3>
 168$ git whatchanged -p ORIG_HEAD.. arch/i386 include/asm-i386 <4>
 169$ git pull git://git.kernel.org/pub/.../jgarzik/libata-dev.git ALL <5>
 170$ git reset --hard ORIG_HEAD <6>
 171$ git prune <7>
 172
 173<1> repeat as needed.
 174<2> extract patches from your branch for e-mail submission.
 175<3> "pull" fetches from "origin" by default and merges.
 176<4> look at the changes since last time we checked, only in the
 177area we are interested in.
 178<5> fetch from a specific branch from a specific repository and and merge.
 179<6> revert the pull.
 180<7> garbage collect leftover objects from reverted pull.
 181------------
 182
 183* Branch off of a specific tag.
 184------------
 185$ git checkout -b private2.6.14 v2.6.14 <1>
 186$ edit/compile/test; git commit -a
 187$ git checkout master
 188$ git format-patch -k -m --stdout v2.6.14..private2.6.14 |
 189  git am -3 -k <2>
 190
 191<1> create a private branch based on a well known (but somewhat behind)
 192tag.
 193<2> forward port all changes in private2.6.14 branch to master branch
 194without a formal "merging".
 195------------
 196
 197
 198Integrator[[Integrator]]
 199------------------------
 200
 201A fairly central person acting as the integrator in a group
 202project receives changes made by others, reviews and integrates
 203them and publishes the result for others to use, using these
 204commands in addition to the ones needed by participants.
 205
 206  * gitlink:git-am[1] to apply patches e-mailed in from your
 207    contributors.
 208
 209  * gitlink:git-pull[1] to merge from your trusted lieutenants.
 210
 211  * gitlink:git-format-patch[1] to prepare and send suggested
 212    alternative to contributors.
 213
 214  * gitlink:git-revert[1] to undo botched commits.
 215
 216  * gitlink:git-push[1] to publish the bleeding edge.
 217
 218
 219Examples
 220~~~~~~~~
 221
 222* My typical GIT day.
 223------------
 224$ git status <1>
 225$ git show-branch <2>
 226$ mailx <3>
 227& s 2 3 4 5 ./+to-apply
 228& s 7 8 ./+hold-linus
 229& q
 230$ git checkout master
 231$ git am -3 -i -s -u ./+to-apply <4>
 232$ compile/test
 233$ git checkout -b hold/linus && git am -3 -i -s -u ./+hold-linus <5>
 234$ git checkout pu && git reset --hard master <6>
 235$ git pull . topic/one topic/two && git pull . hold/linus <7>
 236$ git fetch ko master:refs/tags/ko-master &&
 237  git show-branch master ko-master <8>
 238$ git push ko <9>
 239$ git checkout maint
 240$ git cherry-pick master~4 <10>
 241$ compile/test
 242$ git tag -s -m 'GIT 0.99.9x' v0.99.9x <11>
 243$ git push ko v0.99.9x <12>
 244
 245<1> see what I was in the middle of doing, if any.
 246<2> see what topic branches I have and think about how ready
 247they are.
 248<3> read mails, save ones that are applicable, and save others
 249that are not quite ready.
 250<4> apply them, interactively, with my sign-offs.
 251<5> create topic branch as needed and apply, again with my
 252sign-offs. 
 253<6> restart "pu" every time from the master.
 254<7> and bundle topic branches still cooking.
 255<8> make sure I did not accidentally rewound master beyond what I
 256already pushed out.
 257<9> push out the bleeding edge.
 258<10> backport a critical fix.
 259<11> create a signed tag.
 260<12> push the tag out.
 261------------
 262
 263
 264Repository Administration[[Repository Administration]]
 265------------------------------------------------------
 266
 267A repository administrator uses the following tools to set up
 268and maintain access to the repository by developers.
 269
 270  * gitlink:git-daemon[1] to allow anonymous download from
 271    repository.
 272
 273  * gitlink:git-shell[1] can be used as a 'restricted login shell'
 274    for shared central repository users.
 275
 276  * link:howto/update-hook-example.txt[update hook howto] has a
 277    good example of managing a shared central repository.
 278