Merge pull request #1 from adambard/master

update

1 files changed, 212 insertions, 67 deletions

diff --git a/git.html.markdown b/git.html.markdown
index 04350dd5..582f8863 100644
--- a/git.html.markdown
+++ b/git.html.markdown
@@ -5,26 +5,33 @@ contributors:
     - ["Jake Prather", "http://github.com/JakeHP"]
     - ["Leo Rudberg" , "http://github.com/LOZORD"]
     - ["Betsy Lorton" , "http://github.com/schbetsy"]
+    - ["Bruno Volcov", "http://github.com/volcov"]
+    - ["Andrew Taylor", "http://github.com/andrewjt71"]
+    - ["Jason Stathopulos", "http://github.com/SpiritBreaker226"]
+    - ["Milo Gilad", "http://github.com/Myl0g"]
 filename: LearnGit.txt
 ---
 
-Git is a distributed version control and source code management system. 
+Git is a distributed version control and source code management system.
 
-It does this through a series of snapshots of your project, and it works 
-with those snapshots to provide you with functionality to version and 
+It does this through a series of snapshots of your project, and it works
+with those snapshots to provide you with functionality to version and
 manage your source code.
 
 ## Versioning Concepts
 
 ### What is version control?
 
-Version control is a system that records changes to a file, or set of files, over time.
+Version control is a system that records changes to a file(s), over time.
 
-### Centralized Versioning VS Distributed Versioning
+### Centralized Versioning vs. Distributed Versioning
 
-* Centralized version control focuses on synchronizing, tracking, and backing up files.
-* Distributed version control focuses on sharing changes. Every change has a unique id.
-* Distributed systems have no defined structure. You could easily have a SVN style, 		centralized system, with git.
+* Centralized version control focuses on synchronizing, tracking, and backing 
+up files.
+* Distributed version control focuses on sharing changes. Every change has a 
+unique id.
+* Distributed systems have no defined structure. You could easily have a SVN 
+style, centralized system, with git.
 
 [Additional Information](http://git-scm.com/book/en/Getting-Started-About-Version-Control)
 
@@ -33,65 +40,79 @@ Version control is a system that records changes to a file, or set of files, ove
 * Can work offline.
 * Collaborating with others is easy!
 * Branching is easy!
+* Branching is fast!
 * Merging is easy!
 * Git is fast.
 * Git is flexible.
 
 ## Git Architecture
 
-
 ### Repository
 
-A set of files, directories, historical records, commits, and heads. Imagine it as a source code data structure,
-with the attribute that each source code "element" gives you access to its revision history, among other things.
+A set of files, directories, historical records, commits, and heads. Imagine it
+as a source code data structure, with the attribute that each source code
+"element" gives you access to its revision history, among other things.
 
 A git repository is comprised of the .git directory & working tree.
 
 ### .git Directory (component of repository)
 
-The .git directory contains all the configurations, logs, branches, HEAD, and more.
+The .git directory contains all the configurations, logs, branches, HEAD, and 
+more.
 [Detailed List.](http://gitready.com/advanced/2009/03/23/whats-inside-your-git-directory.html)
 
 ### Working Tree (component of repository)
 
-This is basically the directories and files in your repository. It is often referred to
-as your working directory.
+This is basically the directories and files in your repository. It is often
+referred to as your working directory.
 
 ### Index (component of .git dir)
 
-The Index is the staging area in git. It's basically a layer that separates your working tree
-from the Git repository. This gives developers more power over what gets sent to the Git
-repository.
+The Index is the staging area in git. It's basically a layer that separates 
+your working tree from the Git repository. This gives developers more power 
+over what gets sent to the Git repository.
 
 ### Commit
 
-A git commit is a snapshot of a set of changes, or manipulations to your Working Tree.
-For example, if you added 5 files, and removed 2 others, these changes will be contained
-in a commit (or snapshot). This commit can then be pushed to other repositories, or not!
+A git commit is a snapshot of a set of changes, or manipulations to your 
+Working Tree. For example, if you added 5 files, and removed 2 others, these 
+changes will be contained in a commit (or snapshot). This commit can then be 
+pushed to other repositories, or not!
 
 ### Branch
 
-A branch is essentially a pointer that points to the last commit you made. As you commit,
-this pointer will automatically update and point to the latest commit.
+A branch is essentially a pointer to the last commit you made. As you go on
+committing, this pointer will automatically update to point the latest commit.
+
+### Tag
+
+A tag is a mark on specific point in history. Typically people use this
+functionality to mark release points (v1.0, and so on)
 
 ### HEAD and head (component of .git dir)
 
-HEAD is a pointer that points to the current branch. A repository only has 1 *active* HEAD.
-head is a pointer that points to any commit. A repository can have any number of heads.
+HEAD is a pointer that points to the current branch. A repository only has 1 
+*active* HEAD.  
+head is a pointer that points to any commit. A repository can have any number 
+of heads.
+
+### Stages of Git
+* Modified - Changes have been made to a file but file has not been committed 
+to Git Database yet
+* Staged - Marks a modified file to go into your next commit snapshot
+* Committed - Files have been committed to the Git Database
 
 ### Conceptual Resources
 
 * [Git For Computer Scientists](http://eagain.net/articles/git-for-computer-scientists/)
 * [Git For Designers](http://hoth.entp.com/output/git_for_designers.html)
 
-
 ## Commands
 
-
 ### init
 
-Create an empty Git repository. The Git repository's settings, stored information, 
-and more is stored in a directory (a folder) named ".git".
+Create an empty Git repository. The Git repository's settings, stored 
+information, and more is stored in a directory (a folder) named ".git".
 
 ```bash
 $ git init
@@ -99,15 +120,11 @@ $ git init
 
 ### config
 
-To configure settings. Whether it be for the repository, the system itself, or global
-configurations.
-
+To configure settings. Whether it be for the repository, the system itself,
+or global configurations ( global config file is `~/.gitconfig` ).
 
 ```bash
 # Print & Set Some Basic Config Variables (Global)
-$ git config --global user.email
-$ git config --global user.name
-
 $ git config --global user.email "MyEmail@Zoho.com"
 $ git config --global user.name "My Name"
 ```
@@ -131,13 +148,26 @@ $ git help -a
 $ git help add
 $ git help commit
 $ git help init
+# or git <command_here> --help
+$ git add --help
+$ git commit --help
+$ git init --help
 ```
 
-### status
+### ignore files
 
-To show differences between the index file (basically your working copy/repo) and the current
-HEAD commit.
+To intentionally untrack file(s) & folder(s) from git. Typically meant for
+private & temp files which would otherwise be shared in the repository.
+
+```bash
+$ echo "temp/" >> .gitignore
+$ echo "private_key" >> .gitignore
+```
+
+### status
 
+To show differences between the index file (basically your working copy/repo)
+and the current HEAD commit.
 
 ```bash
 # Will display the branch, untracked files, changes and other differences
@@ -149,8 +179,8 @@ $ git help status
 
 ### add
 
-To add files to the current working tree/directory/repo. If you do not `git add` new files to the
-working tree/directory, they will not be included in commits!
+To add files to the staging area/index. If you do not `git add` new files to 
+the staging area/index, they will not be included in commits!
 
 ```bash
 # add a file in your current working directory
@@ -161,11 +191,18 @@ $ git add /path/to/file/HelloWorld.c
 
 # Regular Expression support!
 $ git add ./*.java
+
+# You can also add everything in your working directory to the staging area.
+$ git add -A
 ```
 
+This only adds a file to the staging area/index, it doesn't commit it to the
+working directory/repo.
+
 ### branch
 
-Manage your branches. You can view, edit, create, delete branches using this command.
+Manage your branches. You can view, edit, create, delete branches using this 
+command.
 
 ```bash
 # list existing branches & remotes
@@ -185,38 +222,85 @@ $ git branch -m myBranchName myNewBranchName
 $ git branch myBranchName --edit-description
 ```
 
+### tag
+
+Manage your tags
+
+```bash
+# List tags
+$ git tag
+
+# Create a annotated tag
+# The -m specifies a tagging message, which is stored with the tag.
+# If you don’t specify a message for an annotated tag,
+# Git launches your editor so you can type it in.
+$ git tag -a v2.0 -m 'my version 2.0'
+
+# Show info about tag
+# That shows the tagger information, the date the commit was tagged,
+# and the annotation message before showing the commit information.
+$ git show v2.0
+
+# Push a single tag to remote
+$ git push origin v2.0
+
+# Push a lot of tags to remote
+$ git push origin --tags
+```
+
 ### checkout
 
-Updates all files in the working tree to match the version in the index, or specified tree.
+Updates all files in the working tree to match the version in the index, or 
+specified tree.
 
 ```bash
 # Checkout a repo - defaults to master branch
 $ git checkout
+
 # Checkout a specified branch
 $ git checkout branchName
-# Create a new branch & switch to it, like: "git branch <name>; git checkout <name>"
+
+# Create a new branch & switch to it
+# equivalent to "git branch <name>; git checkout <name>"
+
 $ git checkout -b newBranch
 ```
 
 ### clone
 
 Clones, or copies, an existing repository into a new directory. It also adds
-remote-tracking branches for each branch in the cloned repo, which allows you to push
-to a remote branch.
+remote-tracking branches for each branch in the cloned repo, which allows you 
+to push to a remote branch.
 
 ```bash
 # Clone learnxinyminutes-docs
 $ git clone https://github.com/adambard/learnxinyminutes-docs.git
+
+# shallow clone - faster cloning that pulls only latest snapshot
+$ git clone --depth 1 https://github.com/adambard/learnxinyminutes-docs.git
+
+# clone only a specific branch
+$ git clone -b master-cn https://github.com/adambard/learnxinyminutes-docs.git --single-branch
 ```
 
 ### commit
 
-Stores the current contents of the index in a new "commit." This commit contains
-the changes made and a message created by the user.
+Stores the current contents of the index in a new "commit." This commit 
+contains the changes made and a message created by the user.
 
 ```bash
 # commit with a message
 $ git commit -m "Added multiplyNumbers() function to HelloWorld.c"
+
+# signed commit with a message (user.signingkey must have been set
+# with your GPG key e.g. git config --global user.signingkey 5173AAD5)
+$ git commit -S -m "signed commit message"
+
+# automatically stage modified or deleted files, except new files, and then commit
+$ git commit -a -m "Modified foo.php and removed bar.php"
+
+# change last commit (this deletes previous commit with a fresh commit)
+$ git commit --amend -m "Correct message"
 ```
 
 ### diff
@@ -254,7 +338,7 @@ $ git config --global alias.g "grep --break --heading --line-number"
 $ git grep 'variableName' -- '*.java'
 
 # Search for a line that contains "arrayListName" and, "add" or "remove"
-$ git grep -e 'arrayListName' --and \( -e add -e remove \) 
+$ git grep -e 'arrayListName' --and \( -e add -e remove \)
 ```
 
 Google is your friend; for more examples
@@ -268,11 +352,14 @@ Display commits to the repository.
 # Show all commits
 $ git log
 
-# Show X number of commits
-$ git log -n 10
+# Show only commit message & ref
+$ git log --oneline
 
 # Show merge commits only
 $ git log --merges
+
+# Show all commits represented by an ASCII graph
+$ git log --graph
 ```
 
 ### merge
@@ -289,7 +376,7 @@ $ git merge --no-ff branchName
 
 ### mv
 
-Rename or move a file	
+Rename or move a file
 
 ```bash
 # Renaming a file
@@ -311,11 +398,15 @@ Pulls from a repository and merges it with another branch.
 # Update your local repo, by merging in new changes
 # from the remote "origin" and "master" branch.
 # git pull <remote> <branch>
-# git pull => implicitly defaults to => git pull origin master
 $ git pull origin master
 
+# By default, git pull will update your current branch
+# by merging in new changes from its remote-tracking branch 
+$ git pull
+
 # Merge in changes from remote branch and rebase
-# branch commits onto your local repo, like: "git pull <remote> <branch>, git rebase <branch>"
+# branch commits onto your local repo, like: "git fetch <remote> <branch>, git 
+# rebase <remote>/<branch>"
 $ git pull origin master --rebase
 ```
 
@@ -324,32 +415,37 @@ $ git pull origin master --rebase
 Push and merge changes from a branch to a remote & branch.
 
 ```bash
-# Push and merge changes from a local repo to a 
+# Push and merge changes from a local repo to a
 # remote named "origin" and "master" branch.
 # git push <remote> <branch>
-# git push => implicitly defaults to => git push origin master
 $ git push origin master
 
+# By default, git push will push and merge changes from
+# the current branch to its remote-tracking branch 
+$ git push
+
 # To link up current local branch with a remote branch, add -u flag:
 $ git push -u origin master
 # Now, anytime you want to push from that same local branch, use shortcut:
-$ git push 
+$ git push
 ```
 
 ### stash
 
-Stashing takes the dirty state of your working directory and saves it on a stack of unfinished changes that you can reapply at any time.
+Stashing takes the dirty state of your working directory and saves it on a 
+stack of unfinished changes that you can reapply at any time.
 
-Let's say you've been doing some work in your git repo, but you want to pull from the remote.
-Since you have dirty (uncommited) changes to some files, you are not able to run `git pull`.
-Instead, you can run `git stash` to save your changes onto a stack!
+Let's say you've been doing some work in your git repo, but you want to pull
+from the remote. Since you have dirty (uncommitted) changes to some files, you
+are not able to run `git pull`. Instead, you can run `git stash` to save your
+changes onto a stack!
 
 ```bash
 $ git stash
 Saved working directory and index state \
   "WIP on master: 049d078 added the index file"
   HEAD is now at 049d078 added the index file
-  (To restore them type "git stash apply") 
+  (To restore them type "git stash apply")
 ```
 
 Now you can pull!
@@ -368,7 +464,8 @@ nothing to commit, working directory clean
 ```
 
 You can see what "hunks" you've stashed so far using `git stash list`.
-Since the "hunks" are stored in a Last-In-First-Out stack, our most recent change will be at top.
+Since the "hunks" are stored in a Last-In-First-Out stack, our most recent 
+change will be at top.
 
 ```bash
 $ git stash list
@@ -396,9 +493,10 @@ Now you're ready to get back to work on your stuff!
 
 [Additional Reading.](http://git-scm.com/book/en/v1/Git-Tools-Stashing)
 
-### rebase (caution) 
+### rebase (caution)
 
-Take all changes that were committed on one branch, and replay them onto another branch.
+Take all changes that were committed on one branch, and replay them onto 
+another branch.
 *Do not rebase commits that you have pushed to a public repo*.
 
 ```bash
@@ -412,8 +510,8 @@ $ git rebase master experimentBranch
 ### reset (caution)
 
 Reset the current HEAD to the specified state. This allows you to undo merges,
-pulls, commits, adds, and more. It's a great command but also dangerous if you don't
-know what you are doing.
+pulls, commits, adds, and more. It's a great command but also dangerous if you 
+don't know what you are doing.
 
 ```bash
 # Reset the staging area, to match the latest commit (leaves dir unchanged)
@@ -427,11 +525,48 @@ $ git reset --hard
 $ git reset 31f2bb1
 
 # Moves the current branch tip backward to the specified commit
-# and makes the working dir match (deletes uncommited changes and all commits
+# and makes the working dir match (deletes uncommitted changes and all commits
 # after the specified commit).
 $ git reset --hard 31f2bb1
 ```
 
+### reflog (caution)
+
+Reflog will list most of the git commands you have done for a given time period,
+default 90 days.
+
+This give you the chance to reverse any git commands that have gone wrong 
+(for instance, if a rebase has broken your application).
+
+You can do this:
+
+1. `git reflog` to list all of the git commands for the rebase
+
+```
+38b323f HEAD@{0}: rebase -i (finish): returning to refs/heads/feature/add_git_reflog
+38b323f HEAD@{1}: rebase -i (pick): Clarify inc/dec operators
+4fff859 HEAD@{2}: rebase -i (pick): Update java.html.markdown
+34ed963 HEAD@{3}: rebase -i (pick): [yaml/en] Add more resources (#1666)
+ed8ddf2 HEAD@{4}: rebase -i (pick): pythonstatcomp spanish translation (#1748)
+2e6c386 HEAD@{5}: rebase -i (start): checkout 02fb96d
+```
+2. Select where to reset to, in our case its `2e6c386`, or `HEAD@{5}`
+3. 'git reset --hard HEAD@{5}' this will reset your repo to that head
+4. You can start the rebase again or leave it alone.
+
+[Additional Reading.](https://git-scm.com/docs/git-reflog)
+
+### revert
+
+Revert can be used to undo a commit. It should not be confused with reset which 
+restores the state of a project to a previous point. Revert will add a new 
+commit which is the inverse of the specified commit, thus reverting it.
+
+```bash
+# Revert a specified commit
+$ git revert <commit>
+```
+
 ### rm
 
 The opposite of git add, git rm removes files from the current working tree.
@@ -448,14 +583,24 @@ $ git rm /pather/to/the/file/HelloWorld.c
 
 * [tryGit - A fun interactive way to learn Git.](http://try.github.io/levels/1/challenges/1)
 
+* [Learn Git Branching - the most visual and interactive way to learn Git on the web](http://learngitbranching.js.org/)
+
+* [Udemy Git Tutorial: A Comprehensive Guide](https://blog.udemy.com/git-tutorial-a-comprehensive-guide/)
+
+* [Git Immersion - A Guided tour that walks through the fundamentals of git](http://gitimmersion.com/)
+
 * [git-scm - Video Tutorials](http://git-scm.com/videos)
 
 * [git-scm - Documentation](http://git-scm.com/docs)
 
 * [Atlassian Git - Tutorials & Workflows](https://www.atlassian.com/git/)
 
-* [SalesForce Cheat Sheet](https://na1.salesforce.com/help/doc/en/salesforce_git_developer_cheatsheet.pdf)
+* [SalesForce Cheat Sheet](http://res.cloudinary.com/hy4kyit2a/image/upload/SF_git_cheatsheet.pdf)
 
 * [GitGuys](http://www.gitguys.com/)
 
 * [Git - the simple guide](http://rogerdudler.github.io/git-guide/index.html)
+
+* [Pro Git](http://www.git-scm.com/book/en/v2)
+
+* [An introduction to Git and GitHub for Beginners (Tutorial)](http://product.hubspot.com/blog/git-and-github-tutorial-for-beginners)