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diff --git a/git.html.markdown b/git.html.markdown new file mode 100644 index 00000000..184ec14b --- /dev/null +++ b/git.html.markdown @@ -0,0 +1,434 @@ +--- + +language: git +contributors: + - ["Jake Prather", "http://github.com/JakeHP"] +filename: LearnGit.txt + +--- + +Git is a distributed version control and source code management system. + +Git does this through a series of snapshopts of your project, and it works +with those snapshots to provide you with functionality to version and +manage your source code. + +In layman's terms, it's a way of managing, and keeping a detailed historical record, +of 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. + + /////////////////////////////////////// + // 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. + + [Additional Information](http://git-scm.com/book/en/Getting-Started-About-Version-Control) + + /////////////////////////////////////// + // Why Use Git? + /////////////////////////////////////// + + * Can work offline. + * Collaborating with others is easy! + * Branching is easy! + * 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 datastructure, + 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. + [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. + + /////////////////////////////////////// + // Index (component of .git dir) + /////////////////////////////////////// + + The Index is the staging area in git. It's basically 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 repositorys, 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. + + /////////////////////////////////////// + // 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. + + /////////////////////////////////////// + // 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 + /////////////////////////////////////// + + Purpose: + To create an empty Git repository. The Git repository's settings, stored information, + and more is stored in a directory, or folder named, ".git". + + Examples: + $ git init + + /////////////////////////////////////// + // config + /////////////////////////////////////// + + Purpose: + To configure settings. Whether it be for the repository, the system itself, or global + configurations. + + Examples: + + // 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" + + [Learn More About git config.](http://git-scm.com/docs/git-config) + + /////////////////////////////////////// + // help + /////////////////////////////////////// + + Purpose: + To give you quick access to an extremeled detailed guide of each command. Or to + just give you a quick reminder of some semantics. + + Examples: + // Quickly check available commands + $ git help + + // Check all available commands + $ git help -a + + // Command specific help - user manual + // git help <command_here> + $ git help add + $ git help commit + $ git help init + + /////////////////////////////////////// + // status + /////////////////////////////////////// + + Purpose: + To show differences between the index file (basically your working copy/repo) and the current + HEAD commit. + + Examples: + // Will display the branch, untracked files, changes and other differences + $ git status + + // To learn other "tid bits" about git status + $ git help status + + /////////////////////////////////////// + // add + /////////////////////////////////////// + + Purpose: + To add files to the current working tree/directory/repo. If you do not git add files to the + working tree/directory they will not be included in commits! + + Exmaples: + // add a file in your current working directory + $ git add HelloWorld.java + + // add a file in a nested dir + $ git add /path/to/file/HelloWorld.c + + // Regular Expression support! + $ git add ./*.java + + /////////////////////////////////////// + // branch + /////////////////////////////////////// + + Purpose: + Manage your branches. You can view, edit, create, delete branches using this command. + + Examples: + // list existing branches & remotes + $ git branch -a + + // create a new branch + $ git branch myNewBranch + + // delete a branch + $ git branch -d myBranch + + // rename a branch + // git branch -m <oldname> <newname> + $ git branch -m myBranchName myNewBranchName + + // edit a branch's description + $ git branch myBranchName --edit-description + + /////////////////////////////////////// + // checkout + /////////////////////////////////////// + + Purpose: + Updates all files in the working tree to match the version in the index, or specified tree. + + Examples: + // Checkout a repo - defaults to master branch + $ git checkout + // Checkout a specified branch + $ git checkout -b branchName + + /////////////////////////////////////// + // clone + /////////////////////////////////////// + + Purpose: + Clones, or copys, an existing repository into a new directory. It almost adds + remote-tracking branches for each branch in the cloned repo. (which allows you to push + to a remote branch) + + Examples: + // Clone learnxinyminutes-docs + $ git clone https://github.com/adambard/learnxinyminutes-docs.git + + /////////////////////////////////////// + // commit + /////////////////////////////////////// + + Purpose: + Stores the current contents of the index in a new "commit". This commit contains + the changes made and a message created by the user. + + Examples: + // commit with a message + $ git commit -m "Added multiplyNumbers() function to HelloWorld.c" + + /////////////////////////////////////// + // grep + /////////////////////////////////////// + + Purpose: + Allows you to quickly search a repository. + + Optional Configurations: + // Thanks to Travis Jeffery for these + // Set line numbers to be shown in grep search results + $ git config --global grep.lineNumber true + + // Make search results more readable, including grouping + $ git config --global alias.g "grep --break --heading --line-number" + + Examples: + // Search for "variableName" in all java files + $ git grep 'variableName' -- '*.java' + + // Search for a line that contains "arrayListName" and, "add" or "remove" + $ git grep -e 'arrayListName' --and \( -e add -e remove \) + + Google is your friend for more examples + [Git Grep Ninja](http://travisjeffery.com/b/2012/02/search-a-git-repo-like-a-ninja) + + /////////////////////////////////////// + // log + /////////////////////////////////////// + + Purpose: + Display commits to the repository. + + Examples: + // Show all commits + $ git log + + // Show X number of commits + $ git log -n 10 + + // Show merge commits only + $ git log --merges + + /////////////////////////////////////// + // merge + /////////////////////////////////////// + + Purpose: + "Merge" in changes, from external commits, into the current branch. + + Examples: + // Merge the specified branch into the current. + $ git merge branchName + + // Always generate a merge commit when merging + $ git merge --no-ff branchName + + /////////////////////////////////////// + // mv + /////////////////////////////////////// + + Purpose: + Rename or move a file + + Examples: + // Renaming a file + $ git mv HelloWorld.c HelloNewWorld.c + + // Moving a file + $ git mv HelloWorld.c ./new/path/HelloWorld.c + + // Force rename or move + // "existingFile" already exists in the directory, will be overwritten + $ git mv -f myFile existingFile + + /////////////////////////////////////// + // pull + /////////////////////////////////////// + + Purpose: + Pulls from a repository and merges it with another branch. + + Examples: + // Update your local repo, by merging in new changes + // from the remote "origin" and "master" branch. + // git pull <remote> <branch> + $ git pull origin master + + /////////////////////////////////////// + // push + /////////////////////////////////////// + + Purpose: + Push, and merge changes from a branch to a remote & branch. + + Examples: + // 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 + + /////////////////////////////////////// + // rebase (caution) + /////////////////////////////////////// + + Purpose: + 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* + + Examples: + // Rebase experimentBranch onto master + // git rebase <basebranch> <topicbranch> + $ git rebase master oldTest + + [Additional Reading.](http://git-scm.com/book/en/Git-Branching-Rebasing) + + /////////////////////////////////////// + // reset (caution) + /////////////////////////////////////// + + Purpose: + 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. + + Examples: + // Reset the staging area, to match the latest commit (leaves dir unchanged) + $ git reset + + // Reset the staging area, to match the latest commit, and overwrite working dir + $ git reset --hard + + // Moves the current branch tip to the specified commit (leaves dir unchanged) + // all changes still exist in the directory. + $ 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 + // after the specified commit). + $ git reset --hard 31f2bb1 + + /////////////////////////////////////// + // rm + /////////////////////////////////////// + + Purpose: + The opposite of git add, git rm removes files from the current working tree. + + Example: + // remove HelloWorld.c + $ git rm HelloWorld.c + + // Remove a file from a nested dir + $ git rm /pather/to/the/file/HelloWorld.c + +``` + +## Further Information + +* [tryGit - A fun interactive way to learn Git.](http://try.github.io/levels/1/challenges/1) + +* [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) |