Frequently used git commands

date: 2022-04-22 17:48:28

Create a git repository

git init

Set the name and email

Globally

$ git config --global user.name <USER_NAME>
$ git config --global user.email <EMAIL>

Locally

$ git config --local user.name <USER_NAME>
$ git config --local user.email <EMAIL>

Existing configurations

use command

$ git config --list

To get a specific configuration, use command git config <CONFIG_NAME>, e.g.

$ git config user.name

To get help

use command like this, git help <KEYWORD>, e.g.

$ git help config

Check logs

# Check last 4 git logs by printing each log in one line
git log --oneline --graph -4
# Check last one log, w/o modified files
git log -1
# Check last one log, w/ modified files
git log -1 --name-only
# Check last one log, w/ added/modified/deleted files
git log -1 --name-status
# Show commits before/after/between data(s)
git log --oneline --after="2022.06.09" --before="2022.06.12"
git log --oneline --since="2022.06.09" --until="2022.06.12"
git log --oneline --after="2022.06.09"
git log --oneline --since="2022.06.09"
git log --oneline --before="2022.06.12"
git log --oneline --until="2022.06.12"

Add & Commit

If you add a new file which hasn’t been tracked before in the repository, first you have to put this file into the so-called “staged area”, using command below,

git add <FILE_NAME>

If you have already modified a file which has been tracked before in the repository, you also have to put file into the so-called “staged area”, using the command below (indeed same as the command above),

git add <FILE_NAME>

After you have put the file (newly added or already be tracked in repo), you put file(s) into (local) repository using the command below,

git commit

Differences (git diff)

If you modify a file, you can tell the difference by the command below,

git diff

If you have already put the file(s) into the staged area, you will see nothing by ‘git diff’. This time, you should use the command below to tell the differences,

git diff --cached
git diff --staged  --> git version >= 1.61

Use a tool to check the differences of files,

# full
git difftool --tool=tkdiff
# short
git difftool -t <tool_name>

To see all the differences in current branch and master branch, use command below to output those differences,

git format-patch -M master -o <OUTPUT_DIR>

Patch a branch

To patch the current branch with *.patch files, use command,

git am ~/<SOME_DIR>/*.patch

Create/Delete branch

To create a new branch from current master branch, use command,

git checkout -b <BRANCH_NAME> master

To remove/delete a branch (git branch), use command

git branch -d <BRANCH_NAME>

If there’s anything not fully merged, git will stop the deletion. Use force command to do it (if confirmed to delete),

git branch -D <BRANCH_NAME>

Clean untracked files

One way to remove untracked files is,

(1) To see all the untracked files,

git clean -n

Note here the option -n is very important, it just shows files untracked, no deleting

(2) Clean if all the files listed above are supposed to be removed,

git clean -f

Remove unstaged files

To remove unstaged files, use commands below,

(1) For a specific file use:

git checkout <PATH_TO_FILE_TO_REVERT>

(2) For all unstaged files use:

git checkout -- .

Rename a branch

git branch -m <OLD_BRANCH_NAME> <NEW_BRANCH_NAME>

Rebase a branch

1. Switch to a branch which need rebase

git checkout <DEV_BRANCH>

2. Rebase

git rebase master

Show origin information

$ git remote
$ git remote -v
$ git remote show origin

Move a file

git mv <OLD_FILE> <NEW_FILE>

By moving files with git, we notify git about two things

(1) The hello.html file was deleted.

(2) The lib/hello.html file was created.

Both facts are staged immediately and ready for a commit. Git status command reports the file has been moved.

Git aliases

Equals to git checkout

$ git config --global alias.co checkout

Equals to git branch

$ git config --global alias.br branch

Equals to git commit

$ git config --global alias.ci commit

Equals to git status

$ git config --global alias.st status

Steps to create branch & push

Create a new branch in local and then push it to the remote (GitHub) and then track it

# 1. Create a new branch in local
git branch <NEW_BRANCH_NAME>
# 2. Get the remote repo name
git remote
# 3. Push the new branch to remote repo
git push <REMOTE_REPO_NAME> <NEW_BRANCH_NAME>
# Usually remote repo name is 'origin'
git push origin <NEW_BRANCH_NAME>
# 4. Connect this new local branch with the new branch just pushed to the remote repo
git branch --set-upstream-to=origin/<NEW_BRANCH_NAME>
# 5. After that, modify code and push as usaul
git add -A
git commit -m "XXXXX"
git push (or use git push origin <NEW_BRANCH_NAME>)

Remove files and restore files

Reference website git 删除文件与恢复

• A file was deleted locally by shell commands other than git commands, but it was not added to the stage area, use checkout option to restore

  # Remove a file locally by shell commands
  rm <FILE>
  # Restore the file
  git checkout -- <FILE>
  

• A file was deleted locally by shell commands other than git commands, and it was added to the stage area, first use reset command to rollback the file to the status of locally removed, and then use checkout option to restore

  ##### 1st situation
  # Remove a file locally by shell commands
  rm <FILE>
  # Add to staged area (deleted)
  git add <FILE>
  # Rollback
  git reset HEAD <FILE>
  # Restore the file
  git checkout -- <FILE>
  
  ##### 2nd situation
  # Remove a file locally by git command which will add it to staged area (deleted)
  git rm <FILE>
  # Rollback
  git reset HEAD <FILE>
  # Restore the file
  git checkout -- <FILE>
  

• A file was deleted locally either by shell commands or git commands, and it was not only added to the stage area, but also committed to local repository, then we need to use reset --hard <ID> to rollback (ID is got by using git log command)

  ##### 1st situation
  # Remove a file locally by shell commands
  rm <FILE>
  # Add to staged area (deleted)
  git add <FILE>
  # Commit
  git commit -m "Delete a file"
  # Get the version ID by using the log option
  git log --pretty=oneline
  # Rollback
  git reset --hard <ID>
  
  ##### 2nd situation
  # Remove a file locally by git command which will add it to staged area (deleted)
  git rm <FILE>
  # Commit
  git commit -m "Delete a file"
  # Get the version ID by using the log option
  git log --pretty=oneline
  # Rollback
  git reset --hard <ID>
  

• A file was deleted locally either by shell commands or git commands, and it was not only committed to the local repository, but also push to the remote repository (e.g., Github), then following the steps above, and the use git push -fto push the restored files back to the remote repository. Note here -f is a must, because git doesn’t allow lower versions override higher versions.

  ##### 1st situation
  # Remove a file locally by shell commands
  rm <FILE>
  # Add to staged area (deleted)
  git add <FILE>
  # Commit
  git commit -m "Delete a file"
  # Get the version ID by using the log option
  git log --pretty=oneline
  # Rollback
  git reset --hard <ID>
  # Push to remote
  git push -f
  
  ##### 2nd situation
  # Remove a file locally by git command which will add it to staged area (deleted)
  git rm <FILE>
  # Commit
  git commit -m "Delete a file"
  # Get the version ID by using the log option
  git log --pretty=oneline
  # Rollback
  git reset --hard <ID>
  # Push to remote
  git push -f
  

Change repository’s fetch origin

如何修改当前本地的repository目录对应的fetch origin

### Check current fetch & push orign
Pyrad@SSEA $ git remote -v
origin  git@github.com:Pyrad/cpp11.git (fetch)
origin  git@github.com:Pyrad/cpp11.git (push)
origin  git@gitee.com:pyrad/cpp11.git (push)

### Delete current fetch origin
Pyrad@SSEA $ git remote set-url --delete origin git@github.com:Pyrad/cpp11.git

### Check current fetch & push orign again
Pyrad@SSEA $ git remote -v
origin  git@gitee.com:pyrad/cpp11.git (fetch)
origin  git@gitee.com:pyrad/cpp11.git (push)

### Add another repo URL as PUSH origin
Pyrad@SSEA $ git remote set-url --add origin git@github.com:Pyrad/cpp11.git

### Check current fetch & push orign at last
Pyrad@SSEA $ git remote -v
origin  git@gitee.com:pyrad/cpp11.git (fetch)
origin  git@gitee.com:pyrad/cpp11.git (push)
origin  git@github.com:Pyrad/cpp11.git (push)

注意，目前多个fetch的origin是不允许的，所以如果在没有删除旧的fetch origin之前，就直接添加新的，会报错，错误信息如下。

$ git remote set-url origin git@gitee.com:pyrad/cpp11.git
warning: remote.origin.url has multiple values
fatal: could not set 'remote.origin.url' to 'git@gitee.com:pyrad/cpp11.git'

Set editor when committing

修改git提交commit时所使用的编辑器

$ git config --global core.editor "vim"

Change last commit message

修改最后一次提交的commit信息

$ git commit --amend

Git to show messages of only one commit

Only show the names of files modified, w/o diff

git show SHA_COMMIT_KEY --name-only

Permenantly delete commits after a commit number

Answer in Stack Overflow

This will destroy any local modifications after 0d1d7fc32 (0d1d7fc32 is not destroyed)

Don’t do it if you have uncommitted work you want to keep.

git reset --hard 0d1d7fc32

Alternatively, if there’s work to keep

git stash
git reset --hard 0d1d7fc32
git stash pop

This saves the modifications, then reapplies that patch after resetting.

You could get merge conflicts, if you’ve modified things which were changed since the commit you reset to.

Git cheat-sheet from GitLab

git-cheat-sheet.pdf

Git Reset Soft

Going back to HEAD

git reset --soft HEAD

Going back to the commit before HEAD

git reset --soft HEAD^

or equivalent

git reset --soft HEAD~1

Going back to 2 commits before HEAD

git reset --soft HEAD~2

Git show untracked files as a list

git ls-files --others --exclude-standard

This will output a list of files that are not tracked by Git and are not ignored by .gitignore or other exclude files.

You can also use the -z option to separate the file names with null characters instead of newlines.

This can be useful if you want to pipe the output to xargs or other commands that can handle null-delimited input. For example:

git ls-files -z --others --exclude-standard | xargs -0 rm

This will delete all untracked files that are not ignored by Git.

Resolve conflicts when merging from another branch

once conflict occurs after git merge $branch_name, it will show what file has conflicts, and it needs to be resolved before merged.

Just open that file using vi or other text editor, and find conflict marker <<<<<<<<. Then fix the conflicts.

After conflicts are resolved, just add that file(s) by using

git add .

Then commit it by using

git commit

Now it seems like below,

 1 Merge branch 'master' into dev
 2                                                                                 
 3 # Conflicts:                                                                    
 4 #       src/array.cpp
 5 #                                                                               
 6 # It looks like you may be committing a merge.                                  
 7 # If this is not correct, please remove the file                                
 8 #       .git/MERGE_HEAD                                                         
 9 # and try again.                                                                
10                                                                                 
11                                                                                 
12 # Please enter the commit message for your changes. Lines starting              
13 # with '#' will be ignored, and an empty message aborts the commit.             
14 #                                                                               
15 # On branch allangle                                                            
16 # All conflicts fixed but you are still merging.                                
17 #                                                                               
18 # Changes to be committed:                                                      
19 #       modified:   src/array.hpp

It reminds you that current you are committing a merge.

Save and commit, then it’s done.

The simplest way to list conflicted files in Git

What’s the simplest way to list conflicted files in Git?

git diff --name-only --diff-filter=U --relative

Get rid of ‘… does not point to a valid object’ for an old git branch

Stack Overflow - Get rid of …

Clean up all of the missing refs by using the following commands (bash)

git for-each-ref --format="%(refname)" | while read ref; do
    git show-ref --quiet --verify $ref 2>/dev/null || git update-ref -d $ref
done

Refer to git-for-each-ref and git-show-ref for more details.