Linguist

# File lib/linguist/samples.rb, line 116
def self.interpreter_from_shebang(data)
  lines = data.lines.to_a

  if lines.any? && (match = lines[0].match(/(.+)\n?/)) && (bang = match[0]) =~ /^#!/
    bang.sub!(/^#! /, '#!')
    tokens = bang.split(' ')
    pieces = tokens.first.split('/')

    if pieces.size > 1
      script = pieces.last
    else
      script = pieces.first.sub('#!', '')
    end

    script = script == 'env' ? tokens[1] : script

    # "python2.6" -> "python"
    if script =~ /((?:\d+\.?)+)/
      script.sub! $1, ''
    end

    # Check for multiline shebang hacks that call `exec`
    if script == 'sh' &&
      lines[0...5].any? { |l| l.match(/exec (\w+).+\$0.+\$@/) }
      script = $1
    end

    script
  else
    nil
  end
end