I want to use something similar to:
git checkout -- <path>/<file>
You can use
git checkout-index for that, this is a low level command, if you want to export everything, you can use
git checkout-index -a -f --prefix=/destination/path/
To quote the man pages:
The final "/" [on the prefix] is important. The exported name is literally just prefixed with the specified string.
If you want to export a certain directory, there are some tricks involved. The command only takes files, not directories. To apply it to directories, use the 'find' command and pipe the output to git.
find dirname -print0 | git checkout-index --prefix=/path-to/dest/ -f -z --stdin
Also from the man pages:
Intuitiveness is not the goal here. Repeatability is.