Preliminary

Git Install

• git-scm.com - installing Git, note: for Windows preferably use Vim as default editor
• An Illustrated Guide to Git on Windows

Git configuration

There are some important configs to be set. Like user name and email, which is used for commits. Open shell/Git bash:

$ git config --global --list # initially the global config is empty

$ git config --global user.name 'John Doe' # sets globally your user name

$ git config --global user.email '[email protected]'

$ git config --global --list
[email protected]
user.name=Tai 'Mr. T' Truong

Converting line-endings:

$ git config --global core.autocrlf true # converts linefeed (lf) to carriage return + linefeed (crlf) source: https://stackoverflow.com/a/5834094

NOTE: when using Windows tools like notepad then set it to true, when using linux tools like Vi in Git Bash then set it to false.

Vi/Vim Basics

• short introduction here: Basic vi commands
  • there are two modes: when starting vi you are in i) command mode and from there you can switch to ii) insert mode
  • commands can be executed in two modes: vi mode and command mode
    • commands in command mode starts with a double colon ':', e.g. ':q' for quitting the vi editor
    • all other commands in vi mode starts with another character than ':'
  • execute inser command by pressing 'i'
  • in insert mode press escape key for switching back to command mode
• basic commands:
  • 'i' - insert starting from cursor
  • 'I' - insert starting beginning of line
  • 'a' - append starting from cursor
  • 'A' - append starting at end of line
  • 'x' - delete character at cursor
  • 'dd' / 'Ndd' - delete/cut current line, delete more lines like: 2dd, 3dd, 4dd ...
  • 'p' - paste
  • ':q' - quit editor, in case of changes an error message is shown
  • ':q!' - force quit (and discard changes)
  • ':w' - write to file
  • 'ZZ' - save and quit
  • '/searchtext' + ENTER - search for text, press 'n' for next
  • ':s/search/replace/' - search and replace

For example if you enter 'git config --global --edit' it uses vi for editing the global git configuration.

Markdown files (like this README file)

• guideline: GitHub Markdown
• every repo should have a README.md file on top

First steps

git init - Create Local Git Repo

First we open a shell (Git Bash in Windows) and create a new Git repo:

$ git --version
git version 2.21.0.windows.1

$ cd path_to_your_workspace

$ pwd # show current path
/path_to_your_workspace

$ ls # list files from current path

$ mkdir myrepo;cd my repo # create folder for new Git repo; and cd/change to this directory 

$ git init # initialize/create Git repo with a master branch
Initialized empty Git repository in D:/workspace/myrepo/.git/

git status - Show the Working Tree Status

'git status' shows all tracked and untracked files (more about this later in the basic chapters). For initial project it is empty:

$ git status # show status on current branch
On branch master

No commits yet

nothing to commit (create/copy files and use "git add" to track)

While we keep working it may look like this:

$ git status
On branch master
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   file1.txt
        new file:   test1

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   acme/file2.txt

Untracked files:
  (use "git add <file>..." to include in what will be committed)

        test2

Let us create a readme file for our repo:

$ echo 'hello world' > README.md

$ tail README.md
hello world

$ git status
On branch master

No commits yet

Untracked files:
  (use "git add <file>..." to include in what will be committed)

        README.md

nothing added to commit but untracked files present (use "git add" to track)

$ less README.md # show file content, press 'q' for quit

git add - Staging files

In Git only those files are committed that are in the staging area. For committing one or more files Git requires two steps:

1. git add - new (untracked) or changed (modified) files need to be staged / added to the staging area
2. git commit - commit staged files

$ git add README.md

$  git status
On branch master

No commits yet

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)

        new file:   README.md

git rm / git rest - Unstaging Files

One possibility to unstage a file is:

$ git rm --cached README.md
rm 'README.md'

$ git status
On branch master

No commits yet

Untracked files:
  (use "git add <file>..." to include in what will be committed)

        README.md

Another is:

$ git reset README.md

maita@LAPTOP-P4D7LDG2 MINGW64 /d/workspace/myrepo (master)
$ git status
On branch master

No commits yet

Untracked files:
  (use "git add <file>..." to include in what will be committed)

        README.md

Committing files from our staged area

$ git commit -m 'readme describing this repo'
[master (root-commit) 667f237] readme describing this repo
 1 file changed, 1 insertion(+)
 create mode 100644 README.md

$ git status
On branch master
nothing to commit, working tree clean

$ git log
commit 667f2377085e651af65ede3c19bd5fa8c40e425b (HEAD -> master)
Author: Tai 'Mr. T' Truong <[email protected]>
Date:   Mon Sep 9 17:46:23 2019 +0200

    readme describing this repo