```ruby
require 'formula'

class Bash <Formula
  url 'http://ftp.gnu.org/gnu/bash/bash-4.1.tar.gz'
  homepage 'http://www.gnu.org/software/bash/'
  sha1 '3bd1ec9c66f3689f6b3495bdaaf9077b2e5dc150'
  version '4.1.7'

  depends_on 'readline'

  def patches
    patch_level = version.split('.').last.to_i
    {'p0' => (1..patch_level).map { |i| "http://ftp.gnu.org/gnu/bash/bash-4.1-patches/bash41-%03d" % i }}
  end

  def install
    system "./configure", "--prefix=#{prefix}", "--disable-debug", "--disable-dependency-tracking"
    system "make install"
  end
end
```

Bump Bash 4.1 patch level to 9
user
```ruby
require 'formula'

class Bash <Formula
  url 'http://ftp.gnu.org/gnu/bash/bash-4.1.tar.gz'
  homepage 'http://www.gnu.org/software/bash/'
  sha1 '3bd1ec9c66f3689f6b3495bdaaf9077b2e5dc150'
  version '4.1.9'

  depends_on 'readline'

  def patches
    patch_level = version.split('.').last.to_i
    {'p0' => (1..patch_level).map { |i| "http://ftp.gnu.org/gnu/bash/bash-4.1-patches/bash41-%03d" % i }}
  end

  def install
    system "./configure", "--prefix=#{prefix}", "--disable-debug", "--disable-dependency-tracking"
    system "make install"
  end
end
```
assistant