$ git branch testing
$ git branch
* master
 testing

$ ls
README
$ echo 'w3cschool.cc' > test.txt
$ git add .
$ git commit -m 'add test.txt'
[master 048598f] add test.txt
 2 files changed, 1 insertion(+), 3 deletions(-)
 delete mode 100644 hello.php
 create mode 100644 test.txt
$ ls
README test.txt
$ git checkout testing
Switched to branch 'testing'
$ ls
README hello.php

$ git checkout master
Switched to branch 'master'
$ ls
README test.txt

$ git checkout -b newtest
Switched to a new branch 'newtest'
$ git rm test2.txt 
rm 'test2.txt'
$ ls
README test.txt
$ git commit -am 'removed test2.txt'
[newtest 556f0a0] removed test2.txt
 1 file changed, 1 deletion(-)
 delete mode 100644 test2.txt
$ git checkout master
Switched to branch 'master'
$ ls
README test.txt test2.txt

$ git branch
* master
 testing
$ git branch -d testing
Deleted branch testing (was 85fc7e7).
$ git branch
* master

$ git branch
* master
 newtest
$ ls
README test.txt test2.txt
$ git merge newtest
Updating 2e082b7..556f0a0
Fast-forward
 test2.txt | 1 -
 1 file changed, 1 deletion(-)
 delete mode 100644 test2.txt
$ ls
README test.txt

$ git branch
* master
$ cat test.txt
w3cschool.cc
首先，我们创建一个叫做"change_site"的分支，切换过去，我们将内容改为 www.w3cschool.cc 。
$ git checkout -b change_site
Switched to a new branch 'change_site'
$ vim test.txt 
$ head -1 test.txt 
www.w3cschool.cc
$ git commit -am 'changed the site'
[change_site d7e7346] changed the site
 1 file changed, 1 insertion(+), 1 deletion(-)
 

$ git checkout master
Switched to branch 'master'
$ head -1 test.txt 
w3cschool.cc
$ vim test.txt 
$ cat test.txt
w3cschool.cc
新增加一行
$ git diff
diff --git a/test.txt b/test.txt
index 704cce7..f84c2a4 100644
--- a/test.txt
+++ b/test.txt
@@ -1 +1,2 @@
 w3cschool.cc
+新增加一行
$ git commit -am '新增加一行'
[master 14b4dca] 新增加一行
 1 file changed, 1 insertion(+)

$ git merge change_site
Auto-merging test.txt
CONFLICT (content): Merge conflict in test.txt
Automatic merge failed; fix conflicts and then commit the result.
$ cat test.txt 
<<<<<<< HEAD
w3cschool.cc
新增加一行
=======
www.w3cschool.cc
>>>>>>> change_site

$ vim test.txt 
$ cat test.txt 
www.w3cschool.cc
新增加一行
$ git diff
diff --cc test.txt
index f84c2a4,bccb7c2..0000000
--- a/test.txt
+++ b/test.txt
@@@ -1,2 -1,1 +1,2 @@@
- w3cschool.cc
+ www.w3cschool.cc
 +新增加一行

$ git status -s
UU test.txt
$ git add test.txt 
$ git status -s
M test.txt
$ git commit
[master 88afe0e] Merge branch 'change_site'