Helpful git commands

helpful-git-commands

# Useful Git commands

## Config Options

git config --global user.name "First Last"
git config --global user.email "emailaddress"
git config user.email "emailaddress" : sets email address for a repo instead of globally
git config user.email : shows which email address it is using in the repo you're currently in
git config --global core.editor emacs : should you want to specifiy an editor for interactive commands See [associating text editors with Git](https://help.github.com/articles/associating-text-editors-with-git/) for more options
git config --global merge.tool opendiff : specify a merge tool (OSX only)
git config --list : lists the config options you have set
git config --global alias.mylog "log --pretty=format:'%h %s [%an] --graph'" : create an alias called mylog that runs git log with your choice of flags
git config --global alias.co checkout : create an alias called co that calls git checkout

## Diffs
 
git diff filename : the diff of the differences between the **unstaged** file and the last commit
git diff --staged filename : the diff of the differences between the **staged** file and the last commit
git diff HEAD : the same as git diff
git diff HEAD^ : the parent of the latest commit
git diff HEAD^ ..HEAD : the second most recent commit vs the most recent
git diff HEAD^^ : the grandparent of the latest commit
git diff HEAD~5 : five commits ago
git diff SHA .. SHA : the diff between two SHAs
git diff brancha branchb : the diff between two branches
You can also use the same time ranges as in git log (see below)
 
## Staging
 
git reset HEAD filename : remove file from staging
git checkout -- filename : remove all the changes from the file and revert to its state in the last commit
 
## Committing
 
git commit -a -m "message" : commit all currently tracked files
git commit --amend -m "message" : use altering a file and wanting to amend it to the last commit. **Don't do after a push**
git reset --soft HEAD^ : undo everything from the last commit and move it back into staging (^^ == last two commits, etc). **Don't do after a push**
git reset --hard HEAD^ : completely remove the last commit and all changes (^^ == last two commits, etc). **Don't do after a push**
 
## Branches
 
git checkout -b branchname : create a new branch and switch branches
git checkout branchname : switch branches
git merge branchname : merge branches (make sure to be on the master to merge a branch into it)
git branch -d branchname : delete a branch
git branch -r : show all remote branches **note: doesn't check for new branches**
git remote show origin: show remote branches and whether they're tracked or not, the local branches and which remote branches they merge with, and also the local branches and where they're configured when a git push happens. This command goes to the remote and tells you if any local branches are out of date.
git fetch : get remote branches but don't auto merge them
git fetch -t : get remote tags
git remote prune origin : prune (i.e. clean up) "stale" (i.e. no longer there) references to remote branches

## Pushing

git push origin :branchname : deletes remote branch
git push origin branchname : push to remote branch and start tracking it
git push origin localbranchname:remotebranchname : push to origin and connect the local branch name to a differently named remote branch. 

## Tags

git tag: list all tags
git tag -a tagname -m "tag description" : add a tag name (e.g. git tag -a v1.0 -m "deployed version 1.0")
git push --tags : push tags to remote. If you don't do this, the tags remain local.
git checkout tagname : checkout the code at that commit

## git log

git config --global color.ui=true : will add colour to git's command line output
git log --oneline -p : the p (i.e. patch) flag shows line-by-line what was added and removed
git log --oneline --stat : shows how many insertions and deletions were made for each file in each commit
git log --oneline --graph : show a visual representation of the branches and the commits on them
git log --pretty=oneline : show the commit SHA on the same line as the commit message
git log --pretty=format:"placeholders go here"

| Placeholder | Replaced With |
|---------------|
| %ad | author date |
| %ae | author email |
| %an | author name |
| %h | SHA hash |
| %s | subject |
| %d | ref names |

So, you can do something like this: git log --pretty=format:"%h %ad- %s [%an]"
There are a lot more options via git help log

### Log dates

git log --until=1.minute.ago
git log --since=1.day.ago
git log --since=1.hour.ago
git log --since=1.month.ago --until=2.weeks.ago
git log --since=2000-01-01 --until=2012.12.21

## git blame

git blame filename --date short : gives you the commit hash, author, date, line number, and content of who changed what on a file

## Excluding things

Open up .git/info/exclude (e.g., subl .git/info/exclude) and add the name of a file or folder you want to want to work on but don't want to have it as part of the shared repo.

## Untracking tracked things

git rm --cached filname : this will delete git's record for this thing. It won't be deleted from your machine, only from git.