With file and line number!

github-commits-listing

#!/bin/bash

BRANCH=`git branch | grep '^\*' | awk '{print $2}'`
DIR=`pwd`
REPO=`git remote -v | grep origin | head -1 | sed 's/[^:]*:\([^\.]*\).*/\1/'`
top_level=`git rev-parse --show-toplevel`
full_path=$PWD/$1
relative_path=${full_path#*$top_level/}
line=$2

open "https://github.com/$REPO/blob/$BRANCH/$relative_path#L$line"