How to Test if Git Repository is Shallow?

问题:

When I make a local clone from a repository, the clone fails if the origin repository is shallow.

git clone -l -- . target-dir

As that is not always the case I'd like to find out prior clone but don't know how to do that.

What I tried so far is very little, basically creating error messages on clone. At the moment I just fetch to unshallow and if that fails, I do a plain fetch because if the repo would be shallow, it should be unshallow afterwards:

if ! git fetch --unshallow; then
    git fetch
fi

However there is no guarantee for being unshallow afterwards (remote to fetch from can be shallow, too), so a test for the (un)shallowness of a git repository would be much better.

回答1:

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:

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.