gh_open.sh

#!/usr/bin/env bash

# gh_open.sh
# ==========
# A little utility to open a web browser to the github page for a given file at
# an optional line number, taking into account current git revision. This
# script is handy in coordination with your favorite text editor. Ever look at
# some code and wish you could quickly send your buddy a URL of exactly what
# you're seeing? Just map gh_open.sh to a keyboard shortcut. For best results
# add gh_open.sh to a directory in your $PATH.
#
# Vim, e.g.
# ---------
# nnoremap <leader>g :!gh_open.sh % <C-r>=line('.')<CR><CR>
#

# resolves the absolute path to a given relative file path
function _realpath() {
    rel_path="${1}"

    if hash realpath; then
        realpath "${rel_path}"
    elif hash python; then
        python -c "import os; print(os.path.realpath('$rel_path'))"
    else
        >&2 echo "ERROR: realpath not available"
        exit 3
    fi
}

prog="${0}"
fpath="${1}"
shift
line_num="${1}"

if [[ -z "${line_num}" ]]; then
    line_suffix=
else
    line_suffix="#L${line_num}"
fi

if [[ -z "${fpath}" ]]; then
    >&2 echo "ERROR: file path must be specified."
    >&2 echo "${prog} FILE [LINE_NUMBER]"
    exit 1
fi

abs_fpath=$(_realpath "${fpath}")
pushd $(dirname "${abs_fpath}") > /dev/null

# ensure we're in a git repo
git status &> /dev/null
if [[ "0" -ne $? ]]; then
    >&2 echo "Given file must be within a git repository."
    popd &> /dev/null
    exit 2
fi

gh_url_base=$( \
    git remote -v  \
    | grep fetch  \
    | head -n1  \
    | awk '{ print $2 }'  \
    | sed -e 's/git@//' -e 's/:/\//' -e 's/\.git$//' \
)

repo_relative_fpath=$(git ls-files --full-name "${abs_fpath}")

git_hash=$(git rev-parse HEAD)

url="https://${gh_url_base}/blob/${git_hash}/${repo_relative_fpath}${line_suffix}"

# open the GH url in-browser using an available command
if hash xdg-open; then
    xdg-open "${url}"
elif hash open; then
    open "${url}"
else
    echo "Please manually open URL: ${url}"
fi

popd &> /dev/null