How can I specify custom global gitconfig path?

I'm in a bit of a bind with 开发者_开发问答Git. I'm trying to execute git commit but I need to be able to swtich between ~/.gitconfig1 and ~/.gitconfig2 Is there a command line switch - or anyway to have Git use a different gitconfig file then the ones found at /etc/gitconfig, ~/.gitconfig and .git/config?

I found a way to execute this - it wasn't elegant but it did work - and so far seems to be the only way to get this to work.

Git uses the HOME path to determine where .gitconfig is. I was able to perform something like this:

/home/marco/.silly/.gitconfig
/home/marco/.stupid/.gitconfig
/home/marco/.gitconfig

And when executing Git Commit (which is the only command that requires the .gitconfig) I override the home path.

HOME=/home/marco/.silly/ git commit -m "silly configuration"

You can then use alias to do this easily

alias sillygit="HOME=/home/marco/.silly/ git"
sillygit commit -m "silly stuff"

Mario Ceppi's alias approach can be used in a slightly more elegant way using the -c config=value argument to git:

$ alias sillygit="git -c user.name=Silly -c user.email=silly@silly.org"
$ sillygit commit

This of course assumes you don't mind keeping the differing config keys in your .bashrc or the like instead of in your .gitconfig, and it has the caveat of breaking shell completion.

@amirouche's comment and Emil Lundberg's answer can be combined to actually load another Git config file:

alias git="git -c 'include.path=/some/path/to/my/custom/.gitconfig'"

However, the user's ~/.gitconfig file is still loaded. This approach only overwrites settings from the other git config files.

You can use --git-dir

git --git-dir /home/marco/silly/.git commit ...