How to Test if Git Repository is Shallow?

If your Git is 2.15 or later, run:

git rev-parse --is-shallow-repository

which will print false (not shallow) or true (shallow):

if $(git rev-parse --is-shallow-repository); then
    ... repository is shallow ...
fi

The answer below dates back to Git versions before 2.15.

If your Git is older than 2.15,¹ just test for the file shallow in the Git repository directory:²

if [ -f "$(git rev-parse --git-dir)"/shallow ]; then
    echo this is a shallow repository;
else
    echo not a shallow repository;
fi

or (shorter):

[ -f "$(git rev-parse --git-dir)"/shallow ] && echo true || echo false

You can turn this into a shell function:

test_shallow() {
    [ -f "$(git rev-parse --git-dir)"/shallow ] && echo true || echo false
}

and even automate the Git version checking:

test_shallow() {
    set -- $(git rev-parse --is-shallow-repository)
    if [ x$1 == x--is-shallow-repository ]; then
        [ -f "$(git rev-parse --git-dir)"/shallow ] && set true || set false
    fi
    echo $1
}

¹git --version will print the current version number:

$ git --version
2.14.1

$ git --version
git version 2.7.4

etc. (I have multiple versions on different VMs/machines at this point.) You can also run:

git rev-parse --is-shallow-repository

If it just prints --is-shallow-repository, your Git is pre-2.15 and lacks the option.

²To see why there are double quotes around $(git rev-parse --git-dir), see Tom Hale’s comment. Note that testing this is a bit tricky since git rev-parse --git-dir from the top level of, e.g., the repository /tmp/with space just prints .git; you must be in a subdirectory, such as /tmp/with space/sub to observe the problem.