Git's ignore file and delete file operations

1 Deleting a workspace and staging a file
$ git rm A

2 only delete a file that has been staged, a file will not be tracked. Can execute git add a from new add back to staging
$ git rm--cached A

3 git MV operation at work to rename or move the original file, in the temporary delete the original file. Add a new file to the staging
Git mv c a <=> mv a C + git add a C

4 Ignore file. Gitignore
*. [OA] ignores files ending with o,a
*.PYC ignores all pyc suffix files
!test.pyc This file should not be ignored, need to be traced, if itself with! The opening file can be preceded by a "slash escape", for example \!test.pyc

foo/means ignoring a directory
**/res indicates that the res in the top-level directory is matched, and the res in the other subdirectories is matched

Git's ignore file and delete file operations