- Update only files that git already knows about, staging modified
- content for commit and marking deleted files for removal. This
- is similar
- to what "git commit -a" does in preparation for making a commit,
- except that the update is limited to paths specified on the
- command line. If no paths are specified, all tracked files in the
- current directory and its subdirectories are updated.
+ Only match <filepattern> against already tracked files in
+ the index rather than the working tree. That means that it
+ will never stage new files, but that it will stage modified
+ new contents of tracked files and that it will remove files
+ from the index if the corresponding files in the working tree
+ have been removed.
++
+If no <filepattern> is given, default to "."; in other words,
+update all tracked files in the current directory and its
+subdirectories.