内容提要
基本概念与设计思路
主要讨论 Git 的一些基本概念，同时讨论 Git 的一些设计思路，这对于更好的使用 Git 至关重要
Git 是什么?
Git 更像是一个小型的文件系统, 提供了许多以此为基础构建的工具, 而不仅只是一个版本控制工具
Git 版本控制中的文件状态
git 系统中可以分为 已追踪(traced)和没有追踪(untraced)两类
其中, 已经 traced 的文件,
modified 已修改
staged 已暂存的状态, 等待提交
committed 提交的状态
开始使用
创建一个 Git 项目
想要创建一个 Git 项目非常简单，你可以使用 git init 快速的初始化一个项目
1 | mkdir git-demo |
当然更加常用的是 git clone 从远端仓库直接 clone 一个项目
git add . 所有文件添加到暂缓区git add -u 所有修改的文件添加到暂缓区
查看项目的状态
git status
提交快照
git commit -m “快速的提交”
git commit 打开你的编辑器提交
git log
git add 添加 untracked 的文件
git add 理解为添加内容到下一次提交中, 而不是添加文件到项目中, 更为合适。
1 | git status |
对比修改的状态
git diff 对应 modified
git diff –cached /–staged 对应文件状态 staged 查看修改的内容
3. git 基本操作
初始化项目
本地
mkdir awesome-project
cd awesome-project
git init
git add .
git commit -m “初始化项目”
远端
git clone git/https 地址
git add filename 支持Liux 通配符 . * 等
git commit -m “本次提交的简要信息”
git commit -a -m 相当于 git add and git commit
5. git 与远程服务通信
git clone
git fetch
git push
6. git 高阶操作
fork 分支如果与主分支保持同步
- Github 上操作
- 本地 git 操作
实践指南
日常使用 Git 整理
整理最常使用的 Git 命令以及它们的应用场景
DESCRIPTION
Git users can broadly be grouped into four categories for the purposes of describing here a small set of useful command for everyday Git.
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 the Individual Developer (Participant) section as well.
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 for the care and feeding of Git repositories.
Individual Developer (Standalone)
A standalone individual developer does not exchange patches with other people, and works alone in a single repository, using the following commands.
git-init[1] to create a new repository.
git-log[1] to see what happened.
git-checkout[1] and git-branch[1] to switch branches.
git-add[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-merge[1] to merge between local branches.
git-rebase[1] to maintain topic branches.
git-tag[1] to mark a known point.
Ex01 引入源码开始一个 Git 项目
1 | tar zxf frotz.tar.gz |
Ex02 创建一个新的相关分支并进行开发
1 | git checkout -b alsa-audio (1) |
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 git commit -a later.
to see what changes you are committing.
commit everything, as you have tested, with your sign-off.
look at all your changes including the previous commit.
amend the previous commit, adding all your new changes, using your original message.
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 -10 (to show up to 10 commits), –until=2005-12-10, etc.
view only the changes that touch what’s in curses/ directory, since v2.43 tag.
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.
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-send-email[1] to send your e-mail submission without corruption by your MUA.
git-request-pull[1] to create a summary of changes for your upstream to pull.
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
$ git checkout -b mine master (1)
$ edit/compile/test; git commit -a -s (2)
$ git format-patch master (3)
$ git send-email –to=”person email@example.com“ 00*.patch (4)
$ git checkout master (5)
$ git pull (6)
$ git log -p ORIG_HEAD.. arch/i386 include/asm-i386 (7)
$ git ls-remote –heads http://git.kernel.org/.../jgarzik/libata-dev.git (8)
$ git pull git://git.kernel.org/pub/…/jgarzik/libata-dev.git ALL (9)
$ git reset –hard ORIG_HEAD (10)
$ git gc (11)
(1) checkout a new branch mine from master.
(2) repeat as needed.
(3) extract patches from your branch, relative to master,
(4) and email them.
(5) return to master, ready to see what’s new
(6) git pull fetches from origin by default and merges into the current branch.
(7) immediately after pulling, look at the changes done upstream since last time we checked, only in the area we are interested in.
(8) check the branch names in an external repository (if not known).
(9) fetch from a specific branch ALL from a specific repository and merge it.
(10) revert the pull.
garbage collect leftover objects from reverted pull.
Push into another repository.
satellite$ git clone mothership:frotz frotz (1)
satellite$ cd frotz
satellite$ git config –get-regexp ‘^(remote|branch).‘ (2)
remote.origin.url mothership:frotz
remote.origin.fetch refs/heads/:refs/remotes/origin/
branch.master.remote origin
branch.master.merge refs/heads/master
satellite$ git config remote.origin.push
+refs/heads/:refs/remotes/satellite/ (3)
satellite$ edit/compile/test/commit
satellite$ git push origin (4)
mothership$ cd frotz
mothership$ git checkout master
mothership$ git merge satellite/master (5)
mothership machine has a frotz repository under your home directory; clone from it to start a repository on the satellite machine.
clone sets these configuration variables by default. It arranges git pull to fetch and store the branches of mothership machine to local remotes/origin/* remote-tracking branches.
arrange git push to push all local branches to their corresponding branch of the mothership machine.
push will stash all our work away on remotes/satellite/* remote-tracking branches on the mothership machine. You could use this as a back-up method. Likewise, you can pretend that mothership “fetched” from you (useful when access is one sided).
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 cherry-pick v2.6.14..private2.6.14 (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”. Or longhand
git format-patch -k -m –stdout v2.6.14..private2.6.14 | git am -3 -k
An alternate participant submission mechanism is using the git request-pull or pull-request mechanisms (e.g as used on GitHub (www.github.com) to notify your upstream of your contribution.
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.
This section can also be used by those who respond to git request-pull or pull-request on GitHub (www.github.com) to integrate the work of others into their history. A sub-area lieutenant for a repository will act both as a participant and as an integrator.
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.
Examples
A typical integrator’s Git day.
$ git status (1)
$ git branch –no-merged master (2)
$ mailx (3)
& s 2 3 4 5 ./+to-apply
& s 7 8 ./+hold-linus
& q
$ git checkout -b topic/one master
$ git am -3 -i -s ./+to-apply (4)
$ compile/test
$ git checkout -b hold/linus && git am -3 -i -s ./+hold-linus (5)
$ git checkout topic/one && git rebase master (6)
$ git checkout pu && git reset –hard next (7)
$ git merge topic/one topic/two && git merge 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 && for branch in master maint next pu (11)
do
git show-branch ko/$branch $branch (12)
done
$ git push –follow-tags ko (13)
see what you were in the middle of doing, if anything.
see which branches haven’t been merged into master yet. Likewise for any other integration branches e.g. maint, next and pu (potential updates).
read mails, save ones that are applicable, and save others that are not quite ready (other mail readers are available).
apply them, interactively, with your sign-offs.
create topic branch as needed and apply, again with sign-offs.
rebase internal topic branch that has not been merged to the master or exposed as a part of a stable branch.
restart pu every time from the next.
and bundle topic branches still cooking.
backport a critical fix.
create a signed tag.
make sure master was not accidentally rewound beyond that already pushed out.
In the output from git show-branch, master should have everything ko/master has, and next should have everything ko/next has, etc.
push out the bleeding edge, together with new tags that point into the pushed history.
In this example, the ko shorthand points at the Git maintainer’s repository at kernel.org, and looks like this:
(in .git/config)
[remote “ko”]
url = kernel.org:/pub/scm/git/git.git
fetch = refs/heads/:refs/remotes/ko/
push = refs/heads/master
push = refs/heads/next
push = +refs/heads/pu
push = refs/heads/maint
Repository Administration
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.
git-http-backend[1] provides a server side implementation of Git-over-HTTP (“Smart http”) allowing both fetch and push services.
gitweb[1] provides a web front-end to Git repositories, which can be set-up using the git-instaweb[1] script.
update hook howto has a good example of managing a shared central repository.
In addition there are a number of other widely deployed hosting, browsing and reviewing solutions such as:
gitolite, gerrit code review, cgit and others.
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/inetd.conf
git stream tcp nowait nobody
/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 using git-over-ssh.
e.g. those using: $ git push/pull ssh://host.xz/pub/scm/project
$ 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 require ssh access to the machine.
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
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.
写作原则，在原来已有文章的基础上，写的更详细
配置与帮助
git config
git help
获取与创建项目
git init
git clone
快照基础
git add
git status
git diff
git difftool
git commit
git reset
git rm
git mv
git clean
git branch
git log
git checkout
git merge
git stash
git tag
git remote
git pull
git push
git fetch
