I often do git symbolic-ref HEAD refs/heads/my_branch to move to another branch without touching the index or worktree.
Is there a "porcelain" command or series of commands that does exactly the same thing?
It would probably be something involving git reset and git checkout.
I've seen various answers that purport to give such commands, for example here, but the results always seem to by slightly different, so I always end up giving up and going back to good old symbolic-ref.
I often do git symbolic-ref HEAD refs/heads/my_branch to move to another branch without touching the index or worktree.
That's ... an unusual work-flow. :-) (It does work, and if that's what you want to achieve, that's OK.)
Is there a "porcelain" command or series of commands that does exactly the same thing?
No—at least, not in general.
HEAD is either tied to a branch name (normal state, "on" a branch), or to a commit hash ID ("detached HEAD"). In the normal state, the only porcelain (non-plumbing) way to put a new branch name into HEAD is to use the branch-switching commands: git checkout or, since Git 2.23, git switch. Both of these insist on updating the index and work-tree to whatever extent is required. Sometimes that will be a very small amount of updating, and might be useful to you.
In the detached-HEAD state, if the new state is also to be detached, git reset --soft will do the job—but in that particular case you need to use git update-ref rather than git symbolic-ref when doing the work via a plumbing command. In particular, git reset hash leaves you in detached-HEAD state.
Using git reset when in attached-HEAD state will move the target of HEAD—the branch to which HEAD is attached—to the selected commit, while git symbolic-ref won't.
