open code in github at a specific revision and optionally at a line

gitlink.sh

#!/bin/bash -x

IFS=$'\n'

url_encode() {
  if command -v jq >/dev/null 2>&1; then
    jq -srR 'sub("\n";"")|@uri'
  else
    sed -e 's/ /%20/g'
  fi
}

if [ -n "$1" ]; then
  cd $(dirname "$1") || exit 1
fi

# the checked-out branch
branch=$(git symbolic-ref -q --short HEAD)
: "${branch:=master}"
# the remote for this branch, with fallbacks
remote=$(git config branch.$branch.remote)
: "${remote:=$(git config branch.master.remote)}"
: "${remote:=$(git remote -v|head -n 1|cut -f1)}"
: "${remote:=origin}"
remote_url=$(git config remote.$remote.url)
forge_url=$(echo "$remote_url"|sed -Ee 's,git@([^:]+):,https://\1/,;s,\.git$,,')

# this should always contain a SHA or a tag, but default to branch otherwise
commitish=$(git name-rev --tags --name-only --always --no-undefined HEAD)
if [ -n "$1" ] ; then
  # quoting here looks dodgy
  path="blob/${commitish:-${branch}}/$(git rev-parse --show-prefix)$(basename "$1"|url_encode)${2:+#L$2${3:+-L$3}}"
else
  path="tree/${commitish:-${branch}}"
fi

url="$forge_url/$path"
echo $url
if command -v xdg-open >/dev/null 2>&1; then
  # linux
  xdg-open "$url"
else
  # osx
  open "$url"
fi