How to track but not stage and how to unstage but not untrack?

Question

I have two concise questions:

• How I can track files but without staging them ?
• How I can unstage files for commit without untracking them ?

NOTE: I know that I can do an initial commit to track the files and start from there with my files tracked. But is possible to specifically do what I'm asking above ?

I tried to use git add -N <expr> but it tracks the file and add it for commit:

PS C:\> git add -N fileA
PS C:\> git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#       new file:   fileA
#
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#       modified:   README.md
#       modified:   composer.lock
#       modified:   fileA
#

If I do git reset HEAD fileA or git rm --cached fileA unstages it but also untracks the file. This command git rm fileA suggest me to use the flag -f that removes the file fisically.

So, It is possible to only track but not stage, and to only unstage but not untrack files ?

Answer 1

Update (May 2015)

I tried to use git add -N <expr> but it tracks the file and add it for commit:

That is no longer the case with the upcoming Git 2.5 (Q2 2015).
See "File doesn′t get into the commit after using git add -N"

---

Original answer (March 2013)

How I can unstage files for commit without untracking them ?

this is the official way:

git reset HEAD fileA

But since it is a new file, you would untrack it as well (remove it from the index, without any previous commit referencing it).

Starting tracking a file means having it in a index (stage) or a commit.

I would recommend making a branch for those files, in order to add them/commit them there.
See "What is Tracked files and Untracked files in the context of GIT?"

• Tracked files are files that were in the last snapshot; they can be unmodified, modified, or staged.
• Untracked files are everything else — any files in your working directory that were not in your last snapshot and are not in your staging area (index)

That means that, for a new file, unstaged it means untrack it.

^{(Source: Pro Git Book, 2.2 Git Basics - Recording Changes to the Repository)}
(Thank you, louisfischer, for the update/fix in the comments)

See also "git - how to tell if a file is git tracked (by shell exit code)?".