1. 怎么把修改commit到两个或多个branche

git checkout A
git commit -m "Fixed the bug x"
git checkout B
git cherry-pick A

2. 撤销commit

git reset --soft HEAD~   

3.回滚到过去某一个commit，并把这个作为最新的commmit

# Reset the index to the desired tree
git reset 56e05fced

# Move the branch pointer back to the previous HEAD
git reset --soft HEAD@{1}

git commit -m "Revert to 56e05fced"

# Update working copy to reflect the new commit
git reset --hard

git ignore

1. 添加要删除的文件进.gitignore
2. 删除缓存

git rm -r --cached .
git add .
git commit -m ".gitignore is now working"