> For the complete documentation index, see [llms.txt](https://spartronics4915.gitbook.io/developer-handbook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://spartronics4915.gitbook.io/developer-handbook/git_introduction/git_faq.md).

# FAQ: git, vi, bash shell

Anything that relates to git or git related tools such as vi, or unix commands.

* [Frequently Asked Questions](/developer-handbook/git_introduction/git_faq.md#frequently-asked-questions)
  * [Common bash shell](/developer-handbook/git_introduction/git_faq.md#common-bash-shell)
  * [Common vi commands](/developer-handbook/git_introduction/git_faq.md#common-vi-commands)
  * [Common Git commands](/developer-handbook/git_introduction/git_faq.md#common-git-commands)
    * [How do I revert previous commit?](/developer-handbook/git_introduction/git_faq.md#how-do-i-revert-previous-commit)
    * [What is "non-fast-forward"?](/developer-handbook/git_introduction/git_faq.md#what-is-non-fast-forward)

## Common bash shell

```bash
# print working directory
$ pwd

# list contents of current directory
$ ls
# list contents of <dir>
$ ls <dir>
# list all/hidden files
$ ls -a

# take me to my home directory
$ cd
# change directory to <dir name>
$ cd <dir>
# change to directory above
$ cd ..

# print file to your screen
$ cat <filename>

# make directory
$ mkdir <dir_name>

# delete a file
$ rm <filename>

# recursively delete a directory -- BE VERY CAREFUL WITH THIS COMMAND!!
$ rm -rf <directory-name>

# copy a file from its current directory to another directory location
$ cp <filename> <directory-location>

# move a file from current directory to another directory location
$ mv <filename> <directory-location>
# rename a file in current directory -- applies to filename or directory name
$ mv <oldname> <newname>
# move & rename a file from current directory to directory above
$ mv <filename> ../<new-filename>

# open up an in-terminal text editor (note the shortcuts along the bottom)
$ nano
# edit a file
$ nano <filename>
```

## Common vi commands

Git's default fallback editor is `vi`, a terminal text editor, similar to nano, but with a higher learning curve and more functionality.

Refer to various reference cards, such as [this one](https://www.ks.uiuc.edu/Training/Tutorials/Reference/virefcard.pdf).

It's important to know that vi has two modes: insertion and command. When you first start vi, editor is in command mode. "i" puts the editor in insertation mode, where you can type without triggering commands -- ESC returns the editor into command mode.

Common commands (in command mode):

```bash
# quit w/o saving -- <shift><:>
:q!
# save & quit
:wq
# change to insert mode
i
# delete word
dw
```

## Common Git commands

We gave out a "Git Cheatsheet" at the beginning of the year that is very helpful. An online version can be found [here.](https://services.github.com/on-demand/downloads/github-git-cheat-sheet.pdf)

```bash
# sets the name attached to commits - this should be your full name
git config --global user.name "name"

# sets the email attached to commits - should be the email used for GitHub
git config --global user.email "email"

# makes a new local repository with the specified name
git init <projectname>

# downloads a repository in the current directory
git clone <url>.git

# stages all modified files for commit
git add .

# commits all staged changes with a commit message
git commit -m "Commit message"

# pushes all commited changes to the origin repository
git push origin master

# pulls all changes from the latest version of the code
git pull upstream master

# fetches the latest commits without merging them
git fetch <repository> <branch>

# gets rid of ALL your changes and resets the repository to upstream - use with EXTREME CAUTION
git reset --hard upstream/master
```

### How do I revert previous commit?

Sometimes you mess up, and don't realize it until after committing your changes.

Git makes it easy to *revert* your changes with use of the `git reset` command. Git reset lets you revert to a previous commit hash, which you have to find first with `git log`.

Read more about git reset in [git fundamentals.](https://github.com/Spartronics4915/developers_handbook/tree/f0f8860205ba7056bb793e03ce9377a47a2c4ab1/git_introduction/git_fundamentals/README.md#git-init)

### What is "non-fast-forward"?

When your local repo is behind the repo you are pushing to you will see an error non-fast-forward updates were rejected. That means you need to retrieve the changes before you can push your changes. Read more about [git pull vs git fetch and git merge.](https://github.com/Spartronics4915/developers_handbook/tree/f0f8860205ba7056bb793e03ce9377a47a2c4ab1/git_introduction/git_fundamentals/README.md)