I have found a post.
But still don't know what is the different between
git checkout <filename>
git checkout -- <filename>
The special "option"
-- means "treat every argument after this point as a file name, no matter what it looks like." This is not Git-specific, it's a general Unix command line convention. Normally you use it to clarify that an argument is a file name rather than an option, e.g.
rm -f # does nothing rm -- -f # deletes a file named "-f"
git checkout1 also takes
-- to mean that subsequent arguments are not its optional "treeish" parameter specifying which commit you want.
So in this context it's safe to use
-- always, but you need it when the file you want to revert has a name that begins with
-, or is the same as the name of a branch. Some examples for branch/file disambiguation:
git checkout README # would normally discard uncommitted changes # to the _file_ "README" git checkout master # would normally switch the working copy to # the _branch_ "master" git checkout -- master # discard uncommitted changes to the _file_ "master"
and option/file disambiguation:
git checkout -p -- README # interactively discard uncommitted changes # to the file "README" git checkout -- -p README # unconditionally discard all uncommitted # changes to the files "-p" and "README"
I'm not sure what you do if you have a branch whose name begins with
-. Perhaps don't do that in the first place.
1 in this mode; "checkout" can do several other things as well. I have never understood why git chose to implement "discard uncommitted changes" as a mode of the "checkout" subcommand, rather than "revert" like most other VCSes, or "reset" which I think might make more sense in git's own terms.