Tips

git

Version control tips with git and https://github.com.

Remove Branches

git branch -d MY_BRANCH                      # Delete local MY_BRANCH
git push origin :MY_BRANCH                   # Delete remote MY_BRANCH
git remote prune origin --dry-run            # Confirm which branches have been removed from remote
git remote prune origin                      # Remove them from local

Basic Usage

git checkout MASTER-BRANCH                   # Checkout the canonical source
git pull --rebase                            # Ensure most recent changes are in
git checkout -b MY_BRANCH                    # Create a local branch
git push --set-upstream origin MY_BRANCH     # Push it to origin, to work from it
git config --global push.default current     # To automatically do above henceforth
... Now make all your needed changes
git add .                                    # Add your changes
git commit -m "my changes"                   # Commit your changes
... Create a pull request (PR) via the web UI, have it peer-review, then merge it

General

git diff branch_A branch_B                   # Compare two branches
git config user.email <email>
git clone git@github.com:Org/MyRepo.git      # Clone via SSH
git clone https://github.com/Org/MyRepo.git  # Clone via HTTPS
git clone /data/tech/code/trix.git trix      # Clone bare local repo (in iCloud, etc)

git pull                                     # Pick up recent changes from master
git add .                                    # Update local repo with all recent changes (b4 committing)
git commit -m "message"                      # Commit all recent changes to current branch (local copy)
git push                                     # Commit your local copy to OFFICIAL master branch

git branch -a                                # Display all branches
git checkout branchA                         # Switch to branch 'branchA'
git log -p                                   # Show full description of recent commits
git log --pretty=oneline                     # Show prettified recent comments

git checkout SOURCE -- FILE/PATH/HERE        # Bring FILE/PATH/HERE from SRC to current branch         
git checkout SOURCE -- .                     # Bring all the files from SRC to current branch         
git diff --stat=140 main                     # Great view comparison of current branch to main
git branch --contains GITHASH                # Search For Specific Hash Across Branches

git mergetool                                      # Resolve Conflicts
git config --global credential.helper osxkeychain  # Store Credentials on macOS Keychain

Switch from master to main

git branch -m master main
git push -u origin main
# Now go to the SCM UI and change to main branch
git push origin --delete master

Fork and Sync Repositories

git remote -v                                               # List the current remotes
git remote add upstream https://github.com/user/repo        # Add remote upstream of fork
git remote set-url --push upstream DISABLE                  # Disable pushes for above (since you can't anyway)
git checkout master                                         # Ensure you're on your fork's master branch
git fetch upstream                                          # fetch upstream branches
git merge upstream/master                                   # Merge upstream master
git push

Additional Origins

git remote set-url origin git@github.com:user/repo2             # Replace origin
git remote set-url --add origin https://github.com/user/repo3   # Add another origin

Squash Commits

Squash or clump commits by moving to a new branch:

   git checkout OLD_BRANCH
   git diff main > ../changes.diff
   git checkout main
   git pull
   git checkout -b NEW_BRANCH
   git apply ../changes.diff
   git commit -m "Squashed OLD_BRANCH changes"
   git push
   # Delete OLD_BRANCH locally and remotely

Revert to a Previous Commit

When you absolutely need to revert last commits.

• Warning: Know what you’re doing. There’s no way back.
• RECENT VERSIONS OF git HAVE EASIER WAY OF DOING THIS.

git reset --hard HEAD~1  # Change '1' to '2' or however many commits you want to revert back
git push -f

# Below has also worked well, for LAST commit
git reset --hard [previous Commit SHA id here] # Use --soft to keep your changes
git push origin [branch Name] -f

Create new Git Origin Repo, Local or Remote

# Populate myproject directory with initial required files to be commited
cd myproject
git init
git add .
git commit -m "First commit"
# Create local origin directory (preferably a cloud drive) and PUSH to it
mkdir -p ~/data/tech/gitrepos/myproject.git
git init --bare ~/data/tech/gitrepos/myproject.git
git remote set-url origin ~/data/tech/gitrepos/myproject.git
git remote -v   # To confirm where origin is
git push
# OR create GitHub remote origin and PUSH to it
# Manually create bare repo in Github via Web UI
git remote add origin git@github.com:username/myproject
git remote -v   # To confirm where origin is
git push

Tags

git tag                                 # List tags
git tag -l "v1.8.5*"                    # Search tags
git tag -a v1.4 -m "my version 1.4"     # Create/annotate a tag
git tag -a v1.2 9fceb02                 # Tag existing commit
git push origin v1.5                    # Share tag by pushing to origin
git push origin --tags                  # Share all tags
git checkout tags/v2.0.0 -b NEW_BRANCH  # Create new branch from a tag
git tag -d v2.0.0                       # Delete a tag locally ...
git push origin :refs/tags/v2.0.0       # ... and remotely

Markdown Choice List

    * [ ] Is it still in use?
    * [ ] Should it be maintained and kept active?
    * [ ] Should it be archived for future reference?
    * [ ] Or should it just be deleted with no trace left behind?

List Repos Using Github Token:

curl -u lencap:TOKEN https://api.github.com/orgs/:ORGNAME/repos?type=private

Show Branch in Shell Prompt

To show current git branch in BASH PS1 prompt, do the following:

1. Create this ~/.fast-git-prompt.sh script:

# Copyright (c) 2019 Will Bender. All rights reserved.

# This work is licensed under the terms of the MIT license.
# For a copy, see <https://opensource.org/licenses/MIT>.

# Very fast __git_ps1 implementation
# Inspired by https://gist.github.com/wolever/6525437
# Mainly this is useful for Windows users stuck on msys, cygwin, or slower wsl 1.0 because git/fs operations are just slower
# Caching can be added by using export but PROMPT_COMMAND is necessary since $() is a subshell and cannot modify parent state.
# Linux: time __ps1_ps1 (~7ms)
# Windows msys2: time __git_ps1 (~100ms)
# Windows msys2: time git rev-parse --abbrev-ref HEAD 2> /dev/null (~86ms)
# Windows msys2: time __fastgit_ps1 (~1-3ms)

# Simple PS1 without colors using format arg. Feel free to use PROMPT_COMMAND
export PS1="\u@\h \w \$(__fastgit_ps1 '[%s] ')$ "

# 100% pure Bash (no forking) function to determine the name of the current git branch
function __fastgit_ps1 () {
    local headfile head branch
    local dir="$PWD"

    while [ -n "$dir" ]; do
        if [ -e "$dir/.git/HEAD" ]; then
            headfile="$dir/.git/HEAD"
            break
        fi
        dir="${dir%/*}"
    done

    if [ -e "$headfile" ]; then
        read -r head < "$headfile" || return
        case "$head" in
            ref:*) branch="${head##*/}" ;;
            "") branch="" ;;
            *) branch="${head:0:7}" ;;  #Detached head. You can change the format for this too.
        esac
    fi

    if [ -z "$branch" ]; then
        return 0
    fi

    if [ -z "$1" ]; then
        # Default format
        printf "(%s) " "$branch"
    else
        # Use passed format string
        printf "$1" "$branch"
    fi
}

1. Then add below section somewhere in your ~/.bashrc file:

export Grn='\[\e[1;32m\]' Blu='\[\e[1;34m\]'  Rst='\[\e[0m\]' # Color green, blue & reset
# ~/.fast-git-prompt.sh = https://gist.github.com/Ragnoroct/c4c3bf37913afb9469d8fc8cffea5b2f
if [[ -f ~/.fast-git-prompt.sh ]]; then
    source ~/.fast-git-prompt.sh
    export PS1="${Grn}[\h \W]${Rst} \$(__fastgit_ps1 '(${Blu}%s${Rst}) ')$ "
else
    export PS1="${Grn}[\h \W]${Rst}$ "
fi

The script above has been slightly reformated from the original Github Gist.

Host Static Site on Github Repo

Host a simple static public document web site based on Markdown on Github by doing the following:

1. Create a public Github repo with at least 2 files: An index.md and a _config.yml
2. Your repo name must be named <username>.github.io, but if you have your own domain to use for this, then the repo can be named anything
3. index.md is the home page, equivalent to a README.md or index.html file
4. _config.yml tells Github Pages how to render your site, e.g. what theme to use, etc.
5. You can use this very same site as an example
6. Go to Settings section of your repo, then click on Pages under Code and automation
7. Under Source select your main or master branch
8. If using your own DNS domain, say mydomain.com, then set up the www CNAME and Anycast IP addresses as follows:

www.mydomain.com    CNAME    git719.github.io.   # Where git719 is your Github username
@                   A        185.199.111.153     # These 4 are Github's Anycast IP addresses
@                   A        185.199.110.153
@                   A        185.199.109.153
@                   A        185.199.108.153