git-update-branch [options] [--] [<branch>...]
Performs a fast-forward update of the given branches to the upstream tracking branch. If no branches are specified, the current branch is updated.
-h,--help: Print a usage message and exit.-a,--all: Update all local branches (no branch arguments may be given).-q,--quiet: Don't print log messages.--: Treat the remaining arguments as branch names.