configure and customize git

$ git config --global user.name "Luca Greco"
$ git config --global user.email "luca.greco@alcacoop.it"
$ git config --global alias.ci "commit"
$ git config --global alias.who "shortlog -s --"

create some file and ignore junk files

$ echo "Hello, git" > README
$ echo "*~" >> .gitignore

see what’s changed

$ git status
# On branch master
#
# Initial commit
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	README
# .gitignore
nothing added to commit but untracked files present (use "git add" to track)

your first commit

$ git add .
$ git commit -m "Initial commit"
[master (root-commit) 31177ca] Initial commit
 2 files changed, 2 insertions(+), 0 deletions(-)
 create mode 100644 README
 create mode 100644 .gitignore

see what’s changed

$ git status
# On branch master
nothing to commit (working directory clean)

add more changes and see what’s changed (again)

$ echo "More content" >> README
$ git status
# On branch master
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#	modified:   README
#
no changes added to commit (use "git add" and/or "git commit -a")

save (commit) your changes

$ git commit -a -m "add more content"
[master 7ceec5a] add more content
 1 files changed, 1 insertions(+), 0 deletions(-)

check your history (log)

$ git log
commit 7ceec5a7d68c54f8a2377986a7abf38c76cb9e89
Author: Luca Greco <luca.greco@alcacoop.it>
Date:   Sat May 8 19:59:20 2010 +0200

    add more content

commit 31177cadb6ecfdc0752be2b30258134b0bb2d758
Author: Luca Greco  <luca.greco@alcacoop.it>
Date:   Sat May 8 19:57:25 2010 +0200

    Initial commit

undoing your changes

$ rm *

    DOOOOOOOOOOOOOOOOOHHHHHHHH!!!!
    
$ git checkout .

    FFFFFFFFFFIIIIIIIIIIIIIIIIUUUUU!!!

reverting to specific (1/2)

$ git checkout 31177c README

$ git status
# Not currently on any branch.
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#	modified:   README

reverting to specific (2/2)

$ git diff HEAD
diff --git a/README b/README
index fe1efe2..22f4644 100644
--- a/README
+++ b/README
@@ -1,2 +1 @@
 Hello, git
-More content

tag a revision

$ git tag 0.1
$ git tag -l
0.1
$ cat .git/refs/tags/0.1 
7ceec5a7d68c54f8a2377986a7abf38c76cb9e89
$ git checkout 0.1 README
$ git status
# On branch master
nothing to commit (working directory clean)

Create a branch

$ git checkout -b feature1
Switched to a new branch 'feature1'
$ git status
# On branch feature1
nothing to commit (working directory clean)
$ echo "feature1" > feature1
$ git add feature1
$ git commit -m "added feature1 prototype"
[feature1 329576e] added feature1 prototype
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 feature1

switching branches

$ git checkout master
Switched to branch 'master'
$ echo "bugfix" >> README
$ git commit -a -m "bugfix 01"
[master c8aa13f] bugfix 01
 1 files changed, 1 insertions(+), 0 deletions(-)

$ git log --graph --all --oneline
* c8aa13f bugfix 01
| * 329576e added feature1 prototype
|/  
* 7ceec5a add more content
* 31177ca Initial commit

$ git log --graph --all
* commit c8aa13f07ea074cf25ba4b9adfce6fb20ee702a3
| Author: Luca Greco <luca.greco@alcacoop.it>
| Date:   Sat May 8 20:51:36 2010 +0200
| 
|     bugfix 01
|    
| * commit 329576ee58336a01f379b7325cf3e5577f1d6094
|/  Author: Luca Greco <luca.greco@alcacoop.it>
|   Date:   Sat May 8 20:50:09 2010 +0200
|   
|       added feature1 prototype
|  
* commit 7ceec5a7d68c54f8a2377986a7abf38c76cb9e89
| Author: Luca Greco <luca.greco@alcacoop.it>
| Date:   Sat May 8 19:59:20 2010 +0200
| 
|     add more content
| 
* commit 31177cadb6ecfdc0752be2b30258134b0bb2d758
  Author: Luca Greco <luca.greco@alcacoop.it>
  Date:   Sat May 8 19:57:25 2010 +0200
  
      Initial commit

merge a local feature branch

$ git checkout master

$ git merge feature1
Merge made by recursive.
 feature1 |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 feature1

or rebase a short life branch (1/2)

$ git checkout feature1

$ git rebase master
First, rewinding head to replay your work on top of it...
Applying: added feature1 prototype

or rebase a short life branch (2/2)

$ git checkout master
Switched to branch 'master'

$ git merge feature1
Updating c8aa13f..cace0c8
Fast forward
 feature1 |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 feature1

$ git status
# On branch master
nothing to commit (working directory clean)

submodules (1/2)

$ mkdir bigproject
$ cd bigproject

$ git init
Initialized empty Git repository in /tmp/bigproject/.git/

$ git submodule add http://github.com/rpl/hello-world.git hello-world
Initialized empty Git repository in /tmp/bigproject/hello-world/.git/
got fabf8ce92a771c4b2f1b93d9f0cf0383e37d14dc
...

submodules (2/2)

$ git status
# On branch master
#
# Initial commit
#
# Changes to be committed:
#   (use "git rm --cached <file>..." to unstage)
#
#	new file:   .gitmodules
#	new file:   hello-world

$ git commit -m "added hello-world submodule"
[master (root-commit) e1beace] added hello-world submodule
 2 files changed, 4 insertions(+), 0 deletions(-)
 create mode 100644 .gitmodules
 create mode 160000 hello-world

set a submodules to a specific revision (1/2)

$ cd hello-world/

$ git checkout 3fa7c4
Note: moving to '3fa7c4' which isn't a local branch
If you want to create a new branch from this checkout, you may do so
(now or later) by using -b with the checkout command again. Example:
  git checkout -b <new_branch_name>
HEAD is now at 3fa7c46... Added BIT , a horribly verbose language

set a submodules to a specific revision (2/2)

$ cd ..

$ git status
# On branch master
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#	modified:   hello-world
#
no changes added to commit (use "git add" and/or "git commit -a")

$ git commit -a -m "revert hello-world submodule to a previous revision"
[master b008d2a] revert hello-world submodule to a previous revision
 1 files changed, 1 insertions(+), 1 deletions(-)

clone an hosted repository

$ git clone http://github.com/git/hello-world.git
Initialized empty Git repository in /tmp/hello-world/.git/
Getting alternates list for http://github.com/git/hello-world.git
Getting pack list for http://github.com/git/hello-world.git
Getting index for pack 8fdd83b4a87545a242e85a41075c5889ecd8a4e7
Getting pack 8fdd83b4a87545a242e85a41075c5889ecd8a4e7
 which contains 3fa7c46d11b11d61f1cbadc6888be5d0eae21969
walk 3fa7c46d11b11d61f1cbadc6888be5d0eae21969
...

pull from origin

$ git pull origin master
From http://github.com/git/hello-world
 * branch            master     -> FETCH_HEAD
Updating 85a0e40..3fa7c46
Fast forward
 BIT.bit |   81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 81 insertions(+), 0 deletions(-)
 create mode 100644 BIT.bit

add changes to master

$ echo '(insert "Hello world")' > elisp_hw.elisp
$ git add elisp_hw.elisp
$ git commit -m "Added elisp"
[master fabf8ce] Added elisp
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 elisp_hw.elisp

push changes

$ git remote add myfork git@github.com:rpl/hello-world.git
$ git push myfork master
Counting objects: 4, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 295 bytes, done.
Total 3 (delta 1), reused 0 (delta 0)
To git@github.com:rpl/hello-world.git
   3fa7c46..fabf8ce  master -> master

amend

$ git commit -a -m "small fix on REAME"
[branch1 10d2deb] small fix on REAME
 1 files changed, 1 insertions(+), 1 deletions(-)

$ git commit -a -m "small fix on README" --amend
[branch1 5313811] small fix on README
 1 files changed, 1 insertions(+), 1 deletions(-)

resolve conflicts (1/6)

$ git checkout -b branch_xyz HEAD^
Switched to a new branch 'branch_xyz'

$ edit README # create a conflict

$ git commit -a -m "fix and cleanup README"
[branch_xyz 78e4185] fix and cleanup README
 1 files changed, 1 insertions(+), 19 deletions(-)
 
$ git checkout master
Switched to branch 'master'
Your branch is ahead of 'origin/master' by 1 commit.

$ git merge branch_xyz 
Auto-merging README
CONFLICT (content): Merge conflict in README
Automatic merge failed; fix conflicts and then commit the result.

resolve conflicts (2/6)

$ git status
README: needs merge
# On branch master
# Your branch is ahead of 'origin/master' by 1 commit.
#
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#	unmerged:   README
#
no changes added to commit (use "git add" and/or "git commit -a")

resolve conflicts (3/6)

$ git mergetool
merge tool candidates: meld opendiff kdiff3 tkdiff xxdiff tortoisemerge gvimdiff diffuse ecmerge emerge vimdiff
Merging the files: README

Normal merge conflict for 'README':
  {local}: modified
  {remote}: modified
Hit return to start merge resolution tool (meld): 

resolve conflits (6/6)

$ git commit -a -m "MERGE: merged branch_xyz and resolved some conflicts on README"
[master 3217c1f] MERGE: merged branch_xyz and resolved some conflicts on README

resolve rebase conflicts (1/3)

$ git reset HEAD^ ; git checkout . ; git checkout branch_xyz
README: locally modified
Switched to branch 'branch_xyz'

$ edit README # do some other change

$ git commit -a -m "added todo in the README"
[branch_xyz 320e9b4] added todo in the README
 1 files changed, 2 insertions(+), 0 deletions(-)

resolve rebase conflicts (2/3)

$ git rebase master
First, rewinding head to replay your work on top of it...
Applying: fix and cleanup README
error: patch failed: README:1
error: README: patch does not apply
Using index info to reconstruct a base tree...
Falling back to patching base and 3-way merge...
Auto-merging README
CONFLICT (content): Merge conflict in README
Failed to merge in the changes.
Patch failed at 0001 fix and cleanup README

When you have resolved this problem run "git rebase --continue".
If you would prefer to skip this patch, instead run "git rebase --skip".
To restore the original branch and stop rebasing run "git rebase --abort".

resolve rebase conflicts (3/3)

$ git mergetool
[...]

$ git rebase --continue
Applying: fix and cleanup README
Applying: added todo in the README