Vim function to echo the currently edited file's github url

ShowGitHubURL

function ShowGitHubURL()
    " Function to echo the github URL for the currently open file at the
    " current line number. This is useful if for example, you want to quickly
    " share the URL for the file you're working on via, email / IRC etc.
    "
    " This can also be easily extended to open the browser with the displayed
    " URL using tips such as http://vim.wikia.com/wiki/VimTip306
    "
    " You may add a mapping like this to bind this function to a keystroke:
    " map <Leader>gh :call ShowGitHubURL()<CR>
    "
    " XXX KNOWN ISSUE: file needs to be opened from the 'top' level of the
    " source tree ie: '%' should expand to the filename under the root of the
    " repositories source tree. I don't know (yet) how to fix this.
    " Suggestions/Patches welcome.

    let gh_base = 'github.com'
    let gh_url = system("git remote -v show")
    if strridx(gh_url, gh_base) == -1
        echom "Not within a github repo or github origin not found"
        return
    endif

    " Build the repo's github url
    let remote = split(gh_url)[0]

    let gh_url = split(gh_url, '@')[2]
    let gh_url = split(gh_url)[0]
    let gh_url = substitute(gh_url, ':', '/', '')
    let gh_url = substitute(gh_url, '.git$', '', '')
    let gh_url = 'https://'.gh_url

    " Add the current branch
    let branch = system("git remote show ".remote."| grep 'HEAD branch'")
    let branch = split(branch)[-1]
    let gh_url = gh_url."/blob/".branch

    " Add the current filename and line number
    let gh_url = gh_url . "/" . expand("%") . "#L" . line(".")

    echom gh_url
endfunction

Things I know:

• This probably is bad vimscript. I just hacked it together. I've never bothered actually learning vimscript. Might someday
• The use of grep at L31 makes this *nix only (unless you have grep.exe in cygwin setup). Well, it isn't strictly necessary, you may modify it appropriately to avoid the use of grep (while maintaining the original assumption -- that the github remote might not be named origin
• Despite the last point, I realize that I made the assumption that git remote -v show will show the github origin as the first remote ...ah well, that's because too lazy.

If you improve on this, please do let me know. I really do find this useful.