fugitive.vimプラグインには、:help fugitive-:Gbrowse必要な処理を実行する機能があります。それは一般的にも素晴らしいです。
                                            *fugitive-:Gbrowse*
:[range]Gbrowse         If the remote for the current branch is on GitHub,
                        open the current file, blob, tree, commit, or tag
                        (with git-web--browse) on GitHub.  Otherwise, open the
                        current file, blob, tree, commit, or tag in
                        git-instaweb (if you have issues, verify you can run
                        "git instaweb" from a terminal).  If a range is given,
                        it is appropriately appended to the URL as an anchor.
                        To use with GitHub FI, point g:fugitive_github_domains
                        at a list of domains:
                        let g:fugitive_github_domains = ['git.example.com']
:[range]Gbrowse!        Like :Gbrowse, but put the URL on the clipboard rather
                        than opening it.