Create basic .gitconfig file

setup_gitconfig.rb

#!/usr/bin/ruby

gitconfig = File.expand_path("~/.gitconfig")

if File.file?(gitconfig)
  puts "#{gitconfig} already exists."
  exit 0
end

puts('##',
     '##  Git stores each entry with your name, email, and a unique identifier.',
     '##  The following will set up Git with this information, as well as some ',
     '##  basic settings to make Git easier to use.',
     '##',
     '')

$stdout.sync = true
print "Enter full name: "
full_name = gets.chomp
print "Enter email address: "
email = gets.chomp
print "Enter full path to preferred diff tool (press \"Enter\" to skip): "
user_difftool = gets.chomp

system("git", "config", "--global", "user.name",  full_name)
system("git", "config", "--global", "user.email", email)
system("git", "config", "--global", "color.ui",   "auto")

poss_opendiff_loc = ["/usr/bin/opendiff", "/usr/local/bin/opendiff", "/Developer/usr/bin/opendiff"]
opendiff_loc = ''

poss_opendiff_loc.each do |loc|
  if File.exists?(loc)
    opendiff_loc = loc
    break
  end
end

difftool = ''
if !user_difftool.empty?
  difftool = user_difftool
elsif !opendiff_loc.empty?
  difftool = opendiff_loc
end

if !difftool.empty?
  system("git", "config", "-global", "merge", difftool)
  system("git", "config", "-global", "diff",  difftool)
  system("git", "config", "-global", "mergetool", difftool)
  system("git", "config", "-global", "difftool",  difftool)
end