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Git

Git GUI

Github Desktop

  • simple
  • fast
  • intuitive
  • only core features

GitKraken

  • many features
  • nice UI
  • slow

login

gh auth login

repo

view all repos

gh repo list

create repo

gh repo create

git pull all subdiretories

for i in */.git; do ( echo $i; git -C $i/.. pull; ); done

commands

  • login
    • gh auth login
  • create repo
    • gh repo create

history

https://git-scm.com/book/en/v2/Git-Basics-Viewing-the-Commit-History

  • git log
  • git reflog
    • each commit oneline
  • git log -p abcdef
    • commit details of abcdef

maintenance

doc

optimize your git repo
might free up some space

git maintenance run

git maintenance run --task=gc

Submodule

Add a submodule

git submodule add <remote url> <local path>

Update all submodule

git submodule update

Remove a submodule

git submodule deinit <local path>

line endings lf & crlf

check the eol of a file

auto eol translation

with gitattributes

auto translation for files when checked out (into LF for Unix, CRLF for Windows)

echo ""* text=auto" >> .gitattributes
git commit -m "something"

with core.autocrlf

  • git config --global core.autocrlf true for Windows
    • convert to LF when commit
    • convert to CRLF when checkout
  • git config --global core.autocrlf input for Unix
    • convert to LF when commit

convert entire directory to LF

(there might be some redundant steps but idk & idc)

auto translation for files when checked out (into LF for Unix, CRLF for Windows) 

echo ""* text=auto" >> .gitattributes
git commit -m "something"

renormalize current directory

git add --renormalize .
git commit -m "something"

git rm --cached -r .  # Remove every file from git's index.
git reset --hard      # Rewrite git's index to pick up all the new line endings.

Working on a branch

Integrate new changes into your dev branch

In your dev branch

git rebase <remote>/<target branch>

e.g.

git rebase origin/master

Make your branch identical to a branch

git reset --hard <remote>/<target branch>

e.g.

git reset --hard origin/master

Stash

Stash all changes

git stash -u

-u to include untracked files

Show stashed entries

git stash list

Retrieve stash files

git stash apply <number>

The latest one would be 0

delete all commits

git update-ref -d HEAD

https://stackoverflow.com/a/6637891/15493213

reset

git reset HEAD~2 to reset to latest_commit.parent.parent

revert a certain file to a version

git checkout <sha> -- <path-to-file>

discard changes

relevant docs - https://git-scm.com/book/en/v2/Git-Basics-Recording-Changes-to-the-Repository - https://git-scm.com/book/en/v2/Git-Basics-Undoing-Things

for tracked files

  • git reset HEAD --hard
  • git restore .
  • git checkout -- .
    • git checkout -- haha.txt
      • unmodify the modified untracked file haha.txt

for untracked files

  • git clean -df
    • clear all untracked files
  • git clean -f haha.txt
    • clear the untracked file haha.txt

remove remote but keep local

git rm --cached <file>

how many insertions and deletions for a user

git log --pretty=format:'' --numstat --author 'dlccyes' | awk 'NF' | awk '{insertions+=$1; deletions+=$2} END {print NR, "files changed,", insertions, "insertions(+),", deletions, "deletions(+)"}';
https://stackoverflow.com/a/48575013/15493213

all commits

  • git log
  • git reflog
    • every action
  • git log --graph --decorate --oneline $(git rev-list -g --all)
    • tree graph of your git and where HEAD is at
  • commit counts
    • git rev-list HEAD --count

diff

filter-branch - delete a file in all commits

git filter-branch --tree-filter 'rm -f <path/to/file>' --prune-empty HEAD

Note that git filter-branch only creates extra commit and then reroute your git commit graph. The original commits are still there.

git log --graph --decorate --oneline $(git rev-list -g --all)

by user

  • all commits
    • git shortlog
  • commit counts
    • git shortlog -s -n

https://stackoverflow.com/questions/677436/how-do-i-get-the-git-commit-count

squash

using reset & amend

設你有最近 3 個 commit 為

  • 9a7792
  • 9a7791
  • 9a7790
  • 9a7789

想要把三個 commits squash 在一起

  1. git reset --soft 9a7789
  2. git commit --amend OR 直接去 gui
    • new commit message
  3. git push -f
    • 此時 remote & local diverge若 pull 則會把 remote pull 下來剛剛步驟就白費了所以直接 force push
  4. 完成

ref

using rebase & squash

設你有最近 4 個 commit 為

  • 9a7792
  • 9a7791
  • 9a7790
  • 9a7789

想要把 9a7792 & 9a7791 squash 到 97790

  1. git rebase -i 9a7790
  2. 出現 editor，把 9a7792 & 9a7791 改成 squash (注意這時較早的 commit 是在上面)
  3. 出現 editor，把 多個 message 改成單一個 message
  4. git push -f
  5. 完成

ref

https://gitbook.tw/chapters/rewrite-history/merge-multiple-commits-to-one-commit.html

Credential

Store credentials as a text file

  1. git config --global credential.helper store
  2. push or pull in your repo, enter your username & passphrase, then they will be saved to ~/.git-credentials
  3. next time you push or pull, you won't need to enter the credentials

https://stackoverflow.com/questions/35942754

Store credentials in Mac's keychain Access app

Mac will store your credentials there automatically, even if you use credentials.helper store. So if you want to change your password/token, you'll need to go the the keychain Access app for it to take effect.

git config --global XXX YYY will add or change XXX's value to YYY in ~/.gitconfig

partial clone

Clone only a certain directory

git init
git remote add -f origin <url>
git config core.sparsecheckout true
echo <dir1>/ >> .git/info/sparse-checkout
echo <dir2>/ >> .git/info/sparse-checkout
echo <dir3>/ >> .git/info/sparse-checkout
git pull origin master

works like a charm

ref:
- https://stackoverflow.com/a/43902478/15493213 - pasta from https://stackoverflow.com/a/17075665/15493213 - pasta from http://jasonkarns.com/blog/2011/11/15/subdirectory-checkouts-with-git-sparse-checkout/

show branch

show all branch

git branch

show all remote/branch

git branch -a

create branch

git checkout -b <branch_name>

delete branch

delete local branch 

git branch -d <local branch>

delete remote branch 

git push <remote> --delete <branch>
# e.g. git push origin --delete test

if git branch -a still show the deleted branch

git remote prune <remote>

rename branch

git branch -m <old_name> <new_name>

switch branch

git checkout <branch>

set/switch tracking remote branch

git branch -u <remote>/<branch>
# or
git branch --set-upstream-to=<remote>/<branch>
https://stackoverflow.com/a/23458073/15493213

merge branch

To merge branch_1 into branch_2

# in branch_2
git merge branch_1

copy everything from another branch to current branch

git checkout <other_branch> .

https://stackoverflow.com/a/7188232/15493213

push to another branch

Say you're on branch_1 and want to push to branch_2

git push <remote> branch_1:branch_2

or

git push <remote> HEAD:branch_2

https://stackoverflow.com/questions/13897717

Check if you have access to a git repo

You can use

git ls-remote <git repo>

check remote

git remote -v

push to another remote

git push <remote>

add remote

git remote add origin2 http://gitlab.com/name/repo

switch default tracking repo

git branch --set-upstream-to origin2/master

https://stackoverflow.com/a/32469272/15493213

ssh method

You can use the remote starting with git@ and add the ssh public key to your github repo (or account) to use ssh method.

  1. generate ssh key (doc)
    1. open git bash / linux terminal
    2. ssh-keygen -t ed25519 -C <email>
    3. press enter to til the end
    4. eval ssh-agent -s
      • should return Agent pid <a number>
    5. copy the content in ~/.ssh/id_ed25519.pub
  2. add it your github repo github (doc)
    1. go to your repository (or account)
    2. settings
    3. deploy keys (or ssh key)
    4. add key
    5. paste your public key
    6. check "allow write"

tag

https://git-scm.com/book/en/v2/Git-Basics-Tagging

Only point at a specific commit, to indicate version for example.
A tag can't be used on multiple commits.

Delete a tag

from remote

git push --delete origin <tagname>

Troubleshooting

Unsafe directory error

git addressed a security vulnerability and changed something to solve it in April, 2022
see https://github.blog/2022-04-12-git-security-vulnerability-announced/

As a result, git directories can't normally use git by non-owners.

Workarounds:

  1. do git as the owner

  2. Add directories to ignore in gitconfig

git config --global --add safe.directory <your directory>

to add all subdiretories

for dir in */; do git config --global --add safe.directory $(realpath $dir); done

git push hung

Restart ssh agent

killall ssh-agent; eval `ssh-agent`

Ref

XXX: needs merge

git reset -- <path/to/file>

See https://stackoverflow.com/a/9749773/154932132