Managing Files - Git Recipes - page 114

How It Works
The process of storing a new file in a repository always consists of two steps. There
isn't another way to do it. When you create a new file, at first it is untracked , which
means that git doesn't store the file in the repository and doesn't track the contents of
the file. The state of the file returned by $ git status -s command is denoted by
two question marks:
?? new.txt
If you want to store the file in a revision, you first add the file to the staging area. This
is done with:
$ git add new.txt
The staging area is a list of modifications that will be included in the very next re-
vision made with the $ git commit command. The staging area is stored in the
.git/index file. The files added to the staging area are called staged files . After $
git add new.txt the shortened status command $ git status -s prints:
A_ new.txt
As you can see, new files added to the staging area are denoted by A_ .
Hint You can use wildcard characters * and ? for a $ git add command.
When the file is in the staging area you can create a new revision with:
$ git commit -m "Some explanation…"
All the changes that were included in the staging area go into the revision. The file
is stored in a repository and can be now described as unmodified . As you probably no-
ticed the commands:
$ git status
$ git status -s
did not print any information about unmodified files.