git pull
# error: Your local changes to the following files would be overwritten by merge:
#         src/config.js
# Please commit your changes or stash them before you merge.
# Aborting

git stash          # save uncommitted changes
git pull           # pull the remote commits
git stash pop      # restore your saved changes
# If there are conflicts after stash pop, resolve them normally

git status
# fatal: not a git repository (or any of the parent directories): .git

# Option A: initialise a new repository here
git init

# Option B: navigate to the right directory
cd /path/to/your/project
git status

# Option C: clone an existing repo
git clone https://github.com/user/repo.git

git push origin main
# To https://github.com/user/repo.git
#  ! [rejected]        main -> main (fetch first)
# error: failed to push some refs to 'https://github.com/user/repo.git'
# hint: Updates were rejected because the remote contains work that you do
# hint: not have locally. Integrate the remote changes (e.g.
# hint: 'git pull ...') before pushing again.

git pull --rebase origin main
# Rebases your local commits on top of the remote commits

git push origin main
# Now succeeds

git pull origin main
git push origin main

git merge feature-login
# Auto-merging src/auth.js
# CONFLICT (content): Merge conflict in src/auth.js
# Automatic merge failed; fix conflicts and then commit the result.

# 1. See which files conflict
git status

# 2. Open each conflicted file and resolve (editor or merge tool)
git mergetool   # optional: opens a visual tool

# 3. Mark each file as resolved
git add src/auth.js

# 4. Finish the merge
git commit

git checkout abc1234
# Note: switching to 'abc1234'.
#
# You are in 'detached HEAD' state. You can look around, make experimental
# changes and commit them, and you can discard any commits you make in this
# state without impacting any branches by switching back to a branch.
#
# HEAD is now at abc1234 Add login form

git switch -c my-experiment
# HEAD is now pointing at a branch — your commits are safe

# Or, if you just want to go back without saving:
git switch main

git pull origin main
# fatal: refusing to merge unrelated histories

git pull origin main --allow-unrelated-histories
# Git creates a merge commit joining the two histories

# Then push normally
git push origin main

git add my documents/notes.txt
# fatal: pathspec 'documents/notes.txt' did not match any files

git add "my documents/notes.txt"

# Or escape the space:
git add my documents/notes.txt

git push origin main
# git@github.com: Permission denied (publickey).
# fatal: Could not read from remote repository.
#
# Please make sure you have the correct access rights
# and the repository exists.

# 1. Check if your key is loaded
ssh-add -l
# If empty: "The agent has no identities"

# 2. Add your key to the agent
ssh-add ~/.ssh/id_ed25519

# 3. Test the connection
ssh -T git@github.com
# Hi username! You've successfully authenticated...

# 4. If you have no SSH key, generate one
ssh-keygen -t ed25519 -C "you@example.com"
# Then copy the public key to GitHub: Settings → SSH Keys
cat ~/.ssh/id_ed25519.pub

git switch feature-x
# error: Your local changes to the following files would be overwritten by checkout:
#         src/index.js
# Please commit your changes or stash them before you switch branches.
# Aborting

# Option A: stash and switch
git stash
git switch feature-x
git stash pop

# Option B: commit your changes first
git add -A
git commit -m "WIP: save progress"
git switch feature-x

# Option C: discard local changes (Warning: irreversible)
git restore src/index.js
git switch feature-x

git push
# To https://github.com/user/repo.git
#  ! [rejected]        main -> main (non-fast-forward)
# error: failed to push some refs to 'https://github.com/user/repo.git'
# hint: Updates were rejected because the tip of your current branch is behind
# hint: its remote counterpart.

git fetch origin
git rebase origin/main
git push origin main

git pull --rebase
# error: cannot pull with rebase: You have unstaged changes.
# Please commit or stash them.

git stash
git pull --rebase
git stash pop

git remote add origin https://github.com/user/repo.git
# fatal: remote origin already exists.

# Check the current remote URL
git remote -v

# Update the URL instead of adding
git remote set-url origin https://github.com/user/new-repo.git

# Or remove and re-add
git remote remove origin
git remote add origin https://github.com/user/repo.git

git commit -m "my changes"
# On branch main
# nothing to commit, working tree clean

# See what is in your working tree
git status

# Stage specific files
git add src/app.js

# Stage all changes
git add -A

# Now commit
git commit -m "my changes"

git checkout feature-x
# error: The following untracked working tree files would be overwritten by checkout:
#         config/local.json
# Please move or remove them before you switch branches.
# Aborting

# Option A: back up and remove the file
cp config/local.json ~/Desktop/local.json.bak
rm config/local.json
git switch feature-x

# Option B: if you want to keep it tracked, add it first
git add config/local.json
git commit -m "add local config"
git switch feature-x

git clone https://internal.company.com/repo.git
# fatal: unable to access 'https://internal.company.com/repo.git/':
# SSL certificate problem: unable to get local issuer certificate

# Proper fix: tell Git where the CA bundle is
git config --global http.sslCAInfo /path/to/corporate-ca.crt

# For a single repo only
git config http.sslCAInfo /path/to/corporate-ca.crt