Initial extraction of ShellOut from Chef

5 files changed, 1027 insertions, 0 deletions

diff --git a/lib/mixlib/shellout.rb b/lib/mixlib/shellout.rb
new file mode 100644
index 0000000..88a666d
--- /dev/null
+++ b/lib/mixlib/shellout.rb
@@ -0,0 +1,237 @@
+#--
+# Author:: Daniel DeLeo (<dan@opscode.com>)
+# Copyright:: Copyright (c) 2010 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'etc'
+require 'tmpdir'
+require 'chef/log'
+require 'fcntl'
+require 'mixlib/shellout/exceptions'
+
+module Mixlib
+
+  class ShellOut
+    READ_WAIT_TIME = 0.01
+    READ_SIZE = 4096
+    DEFAULT_READ_TIMEOUT = 600
+    DEFAULT_ENVIRONMENT = {'LC_ALL' => 'C'}
+
+    if RUBY_PLATFORM =~ /mswin|mingw32|windows/
+      require 'mixlib/shellout/windows'
+      include ShellOut::Windows
+    else
+      require 'mixlib/shellout/unix'
+      include ShellOut::Unix
+    end
+
+    attr_accessor :user
+    attr_accessor :group
+    attr_accessor :cwd
+    attr_accessor :valid_exit_codes
+    attr_accessor :live_stream
+    attr_accessor :command_log_level
+    attr_accessor :command_log_prepend
+
+    attr_reader :command, :umask, :environment
+    attr_writer :timeout
+    attr_reader :execution_time
+
+    attr_reader :stdout, :stderr, :status
+
+    attr_reader :stdin_pipe, :stdout_pipe, :stderr_pipe, :process_status_pipe
+
+    # === Arguments:
+    # Takes a single command, or a list of command fragments. These are used
+    # as arguments to Kernel.exec. See the Kernel.exec documentation for more
+    # explanation of how arguments are evaluated. The last argument can be an
+    # options Hash.
+    # === Options:
+    # If the last argument is a Hash, it is removed from the list of args passed
+    # to exec and used as an options hash. The following options are available:
+    # * +user+: the user the commmand should run as. if an integer is given, it is
+    #   used as a uid. A string is treated as a username and resolved to a uid
+    #   with Etc.getpwnam
+    # * +group+: the group the command should run as. works similarly to +user+
+    # * +cwd+: the directory to chdir to before running the command
+    # * +umask+: a umask to set before running the command. If given as an Integer,
+    #   be sure to use two leading zeros so it's parsed as Octal. A string will
+    #   be treated as an octal integer
+    # * +returns+:  one or more Integer values to use as valid exit codes for the
+    #   subprocess. This only has an effect if you call +error!+ after
+    #   +run_command+.
+    # * +environment+: a Hash of environment variables to set before the command
+    #   is run. By default, the environment will *always* be set to 'LC_ALL' => 'C'
+    #   to prevent issues with multibyte characters in Ruby 1.8. To avoid this,
+    #   use :environment => nil for *no* extra environment settings, or
+    #   :environment => {'LC_ALL'=>nil, ...} to set other environment settings
+    #   without changing the locale.
+    # * +timeout+: a Numeric value for the number of seconds to wait on the
+    #   child process before raising an Exception. This is calculated as the
+    #   total amount of time that ShellOut waited on the child process without
+    #   receiving any output (i.e., IO.select returned nil). Default is 60
+    #   seconds. Note: the stdlib Timeout library is not used.
+    # === Examples:
+    # Invoke find(1) to search for .rb files:
+    #   find = Chef::ShellOut.new("find . -name '*.rb'")
+    #   find.run_command
+    #   # If all went well, the results are on +stdout+
+    #   puts find.stdout
+    #   # find(1) prints diagnostic info to STDERR:
+    #   puts "error messages" + find.stderr
+    #   # Raise an exception if it didn't exit with 0
+    #   find.error!
+    # Run a command as the +www+ user with no extra ENV settings from +/tmp+
+    #   cmd = Chef::ShellOut.new("apachectl", "start", :user => 'www', :env => nil, :cwd => '/tmp')
+    #   cmd.run_command # etc.
+    def initialize(*command_args)
+      @stdout, @stderr = '', ''
+      @live_stream = nil
+      @command_log_level = :debug
+      @command_log_prepend = nil 
+      @environment = DEFAULT_ENVIRONMENT
+      @cwd = nil
+      @valid_exit_codes = [0]
+
+      if command_args.last.is_a?(Hash)
+        parse_options(command_args.pop)
+      end
+
+      @command = command_args.size == 1 ? command_args.first : command_args
+    end
+
+    def umask=(new_umask)
+      @umask = (new_umask.respond_to?(:oct) ? new_umask.oct : new_umask.to_i) & 007777
+    end
+
+    def uid
+      return nil unless user
+      user.kind_of?(Integer) ? user : Etc.getpwnam(user.to_s).uid
+    end
+
+    def gid
+      return nil unless group
+      group.kind_of?(Integer) ? group : Etc.getgrnam(group.to_s).gid
+    end
+
+    def timeout
+      @timeout || DEFAULT_READ_TIMEOUT
+    end
+
+    # Creates a String showing the output of the command, including a banner
+    # showing the exact command executed. Used by +invalid!+ to show command
+    # results when the command exited with an unexpected status.
+    def format_for_exception
+      msg = ""
+      msg << "---- Begin output of #{command} ----\n"
+      msg << "STDOUT: #{stdout.strip}\n"
+      msg << "STDERR: #{stderr.strip}\n"
+      msg << "---- End output of #{command} ----\n"
+      msg << "Ran #{command} returned #{status.exitstatus}" if status
+      msg
+    end
+
+    def exitstatus
+      @status && @status.exitstatus
+    end
+
+    # Run the command, writing the command's standard out and standard error
+    # to +stdout+ and +stderr+, and saving its exit status object to +status+
+    # === Returns
+    # returns   +self+; +stdout+, +stderr+, +status+, and +exitstatus+ will be
+    # populated with results of the command
+    # === Raises
+    # * Errno::EACCES  when you are not privileged to execute the command
+    # * Errno::ENOENT  when the command is not available on the system (or not
+    #   in the current $PATH)
+    # * ::CommandTimeout  when the command does not complete
+    #   within +timeout+ seconds (default: 60s)
+    def run_command
+      if command_log_prepend
+        Chef::Log.send(command_log_level, "#{command_log_prepend} sh(#{@command})")
+      else
+        Chef::Log.send(command_log_level, "sh(#{@command})")
+      end
+      super
+    end
+
+    # Checks the +exitstatus+ against the set of +valid_exit_codes+. If
+    # +exitstatus+ is not in the list of +valid_exit_codes+, calls +invalid!+,
+    # which raises an Exception.
+    # === Returns
+    # nil::: always returns nil when it does not raise
+    # === Raises
+    # ::ShellCommandFailed::: via +invalid!+
+    def error!
+      unless Array(valid_exit_codes).include?(exitstatus)
+        invalid!("Expected process to exit with #{valid_exit_codes.inspect}, but received '#{exitstatus}'")
+      end
+    end
+
+    # Raises a ::ShellCommandFailed exception, appending the
+    # command's stdout, stderr, and exitstatus to the exception message.
+    # === Arguments
+    # +msg+:  A String to use as the basis of the exception message. The
+    # default explanation is very generic, providing a more informative message
+    # is highly encouraged.
+    # === Raises
+    # ::ShellCommandFailed  always
+    def invalid!(msg=nil)
+      msg ||= "Command produced unexpected results"
+      raise ShellCommandFailed, msg + "\n" + format_for_exception
+    end
+
+    def inspect
+      "<#{self.class.name}##{object_id}: command: '#@command' process_status: #{@status.inspect} " +
+      "stdout: '#{stdout.strip}' stderr: '#{stderr.strip}' child_pid: #{@child_pid.inspect} " +
+      "environment: #{@environment.inspect} timeout: #{timeout} user: #@user group: #@group working_dir: #@cwd >"
+    end
+
+    private
+
+    def parse_options(opts)
+      opts.each do |option, setting|
+        case option.to_s
+        when 'cwd'
+          self.cwd = setting
+        when 'user'
+          self.user = setting
+        when 'group'
+          self.group = setting
+        when 'umask'
+          self.umask = setting
+        when 'timeout'
+          self.timeout = setting
+        when 'returns'
+          self.valid_exit_codes = Array(setting)
+        when 'live_stream'
+          self.live_stream = setting
+        when 'command_log_level'
+          self.command_log_level = setting
+        when 'command_log_prepend'
+          self.command_log_prepend = setting
+        when 'environment', 'env'
+          # passing :environment => nil means don't set any new ENV vars
+          @environment = setting.nil? ? {} : @environment.dup.merge!(setting)
+        else
+          raise InvalidCommandOption, "option '#{option.inspect}' is not a valid option for #{self.class.name}"
+        end
+      end
+    end
+
+
+  end
+end
diff --git a/lib/mixlib/shellout/exceptions.rb b/lib/mixlib/shellout/exceptions.rb
new file mode 100644
index 0000000..417def3
--- /dev/null
+++ b/lib/mixlib/shellout/exceptions.rb
@@ -0,0 +1,8 @@
+module Mixlib
+  class ShellOut
+    class ShellCommandFailed < RuntimeError; end
+    class CommandTimeout < RuntimeError; end
+    class InvalidCommandOption < RuntimeError; end
+  end
+end
+
diff --git a/lib/mixlib/shellout/unix.rb b/lib/mixlib/shellout/unix.rb
new file mode 100644
index 0000000..6e66b2a
--- /dev/null
+++ b/lib/mixlib/shellout/unix.rb
@@ -0,0 +1,223 @@
+module Mixlib
+  class ShellOut
+    module Unix
+
+      # Run the command, writing the command's standard out and standard error
+      # to +stdout+ and +stderr+, and saving its exit status object to +status+
+      # === Returns
+      # returns   +self+; +stdout+, +stderr+, +status+, and +exitstatus+ will be
+      # populated with results of the command
+      # === Raises
+      # * Errno::EACCES  when you are not privileged to execute the command
+      # * Errno::ENOENT  when the command is not available on the system (or not
+      #   in the current $PATH)
+      # * Chef::Exceptions::CommandTimeout  when the command does not complete
+      #   within +timeout+ seconds (default: 60s)
+      def run_command
+        @child_pid = fork_subprocess
+
+        configure_parent_process_file_descriptors
+        propagate_pre_exec_failure
+
+        @result = nil
+        @execution_time = 0
+
+        # Ruby 1.8.7 and 1.8.6 from mid 2009 try to allocate objects during GC
+        # when calling IO.select and IO#read. Some OS Vendors are not interested
+        # in updating their ruby packages (Apple, *cough*) and we *have to*
+        # make it work. So I give you this epic hack:
+        GC.disable
+        until @status
+          ready = IO.select(open_pipes, nil, nil, READ_WAIT_TIME)
+          unless ready
+            @execution_time += READ_WAIT_TIME
+            if @execution_time >= timeout && !@result
+              raise CommandTimeout, "command timed out:\n#{format_for_exception}"
+            end
+          end
+
+          if ready && ready.first.include?(child_stdout)
+            read_stdout_to_buffer
+          end
+          if ready && ready.first.include?(child_stderr)
+            read_stderr_to_buffer
+          end
+
+          unless @status
+            # make one more pass to get the last of the output after the
+            # child process dies
+            if results = Process.waitpid2(@child_pid, Process::WNOHANG)
+              @status = results.last
+              redo
+            end
+          end
+        end
+        self
+      rescue Exception
+        # do our best to kill zombies
+        Process.waitpid2(@child_pid, Process::WNOHANG) rescue nil
+        raise
+      ensure
+        # no matter what happens, turn the GC back on, and hope whatever busted
+        # version of ruby we're on doesn't allocate some objects during the next
+        # GC run.
+        GC.enable
+        close_all_pipes
+      end
+
+      private
+
+      def set_user
+        if user
+          Process.euid = uid
+          Process.uid = uid
+        end
+      end
+
+      def set_group
+        if group
+          Process.egid = gid
+          Process.gid = gid
+        end
+      end
+
+      def set_environment
+        environment.each do |env_var,value|
+          ENV[env_var] = value
+        end
+      end
+
+      def set_umask
+        File.umask(umask) if umask
+      end
+
+      def set_cwd
+        Dir.chdir(cwd) if cwd
+      end
+
+      def initialize_ipc
+        @stdout_pipe, @stderr_pipe, @process_status_pipe = IO.pipe, IO.pipe, IO.pipe
+        @process_status_pipe.last.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
+      end
+
+      def child_stdout
+        @stdout_pipe[0]
+      end
+
+      def child_stderr
+        @stderr_pipe[0]
+      end
+
+      def child_process_status
+        @process_status_pipe[0]
+      end
+
+      def close_all_pipes
+        child_stdout.close  unless child_stdout.closed?
+        child_stderr.close  unless child_stderr.closed?
+        child_process_status.close unless child_process_status.closed?
+      end
+
+      # replace stdout, and stderr with pipes to the parent, and close the
+      # reader side of the error marshaling side channel. Close STDIN so when we
+      # exec, the new program will know it's never getting input ever.
+      def configure_subprocess_file_descriptors
+        process_status_pipe.first.close
+
+        # HACK: for some reason, just STDIN.close isn't good enough when running
+        # under ruby 1.9.2, so make it good enough:
+        stdin_reader, stdin_writer = IO.pipe
+        stdin_writer.close
+        STDIN.reopen stdin_reader
+        stdin_reader.close
+
+        stdout_pipe.first.close
+        STDOUT.reopen stdout_pipe.last
+        stdout_pipe.last.close
+
+        stderr_pipe.first.close
+        STDERR.reopen stderr_pipe.last
+        stderr_pipe.last.close
+
+        STDOUT.sync = STDERR.sync = true
+      end
+
+      def configure_parent_process_file_descriptors
+        # Close the sides of the pipes we don't care about
+        stdout_pipe.last.close
+        stderr_pipe.last.close
+        process_status_pipe.last.close
+        # Get output as it happens rather than buffered
+        child_stdout.sync = true
+        child_stderr.sync = true
+
+        true
+      end
+
+      # Some patch levels of ruby in wide use (in particular the ruby 1.8.6 on OSX)
+      # segfault when you IO.select a pipe that's reached eof. Weak sauce.
+      def open_pipes
+        @open_pipes ||= [child_stdout, child_stderr]
+      end
+
+      def read_stdout_to_buffer
+        while chunk = child_stdout.read_nonblock(READ_SIZE)
+          @stdout << chunk
+          @live_stream << chunk if @live_stream
+        end
+      rescue Errno::EAGAIN
+      rescue EOFError
+        open_pipes.delete_at(0)
+      end
+
+      def read_stderr_to_buffer
+        while chunk = child_stderr.read_nonblock(READ_SIZE)
+          @stderr << chunk
+        end
+      rescue Errno::EAGAIN
+      rescue EOFError
+        open_pipes.delete_at(1)
+      end
+
+      def fork_subprocess
+        initialize_ipc
+
+        fork do
+          configure_subprocess_file_descriptors
+
+          set_group
+          set_user
+          set_environment
+          set_umask
+          set_cwd
+
+          begin
+            command.kind_of?(Array) ? exec(*command) : exec(command)
+
+            raise 'forty-two' # Should never get here
+          rescue Exception => e
+            Marshal.dump(e, process_status_pipe.last)
+            process_status_pipe.last.flush
+          end
+          process_status_pipe.last.close unless (process_status_pipe.last.closed?)
+          exit!
+        end
+      end
+
+      # Attempt to get a Marshaled error from the side-channel.
+      # If it's there, un-marshal it and raise. If it's not there,
+      # assume everything went well.
+      def propagate_pre_exec_failure
+        begin
+          e = Marshal.load child_process_status
+          raise(Exception === e ? e : "unknown failure: #{e.inspect}")
+        rescue EOFError # If we get an EOF error, then the exec was successful
+          true
+        ensure
+          child_process_status.close
+        end
+      end
+
+    end
+  end
+end
diff --git a/lib/mixlib/shellout/version.rb b/lib/mixlib/shellout/version.rb
new file mode 100644
index 0000000..1834e03
--- /dev/null
+++ b/lib/mixlib/shellout/version.rb
@@ -0,0 +1,5 @@
+module Mixlib
+  class Shellout
+    VERSION = "1.0.0.rc.0"
+  end
+end
diff --git a/lib/mixlib/shellout/windows.rb b/lib/mixlib/shellout/windows.rb
new file mode 100644
index 0000000..7c79446
--- /dev/null
+++ b/lib/mixlib/shellout/windows.rb
@@ -0,0 +1,554 @@
+#--
+# Author:: Daniel DeLeo (<dan@opscode.com>)
+# Author:: John Keiser (<jkeiser@opscode.com>)
+# Copyright:: Copyright (c) 2011 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'win32/process'
+require 'windows/handle'
+require 'windows/process'
+require 'windows/synchronize'
+
+module Mixlib
+  class ShellOut
+    module Windows
+
+      include ::Windows::Handle
+      include ::Windows::Process
+      include ::Windows::Synchronize
+
+      TIME_SLICE = 0.05
+
+      #--
+      # Missing lots of features from the UNIX version, such as
+      # uid, etc.
+      def run_command
+
+        #
+        # Create pipes to capture stdout and stderr,
+        #
+        stdout_read, stdout_write = IO.pipe
+        stderr_read, stderr_write = IO.pipe
+        open_streams = [ stdout_read, stderr_read ]
+
+        begin
+
+          #
+          # Set cwd, environment, appname, etc.
+          #
+          app_name, command_line = command_to_run
+          create_process_args = {
+            :app_name => app_name,
+            :command_line => command_line,
+            :startup_info => {
+              :stdout => stdout_write,
+              :stderr => stderr_write
+            },
+            :environment => inherit_environment.map { |k,v| "#{k}=#{v}" },
+            :close_handles => false
+          }
+          create_process_args[:cwd] = cwd if cwd
+
+          #
+          # Start the process
+          #
+          process = Process.create(create_process_args)
+          begin
+
+            #
+            # Wait for the process to finish, consuming output as we go
+            #
+            start_wait = Time.now
+            while true
+              wait_status = WaitForSingleObject(process.process_handle, 0)
+              case wait_status
+                when WAIT_OBJECT_0
+                  # Get process exit code
+                  exit_code = [0].pack('l')
+                  unless GetExitCodeProcess(process.process_handle, exit_code)
+                    raise get_last_error
+                  end
+                  @status = ThingThatLooksSortOfLikeAProcessStatus.new
+                  @status.exitstatus = exit_code.unpack('l').first
+
+                  return self
+                when WAIT_TIMEOUT
+                  # Kill the process
+                  if (Time.now - start_wait) > timeout
+                    raise Chef::Exceptions::CommandTimeout, "command timed out:\n#{format_for_exception}"
+                  end
+
+                  consume_output(open_streams, stdout_read, stderr_read)
+                else
+                  raise "Unknown response from WaitForSingleObject(#{process.process_handle}, #{timeout*1000}): #{wait_status}"
+              end
+
+            end
+
+          ensure
+            CloseHandle(process.thread_handle)
+            CloseHandle(process.process_handle)
+          end
+
+        ensure
+          #
+          # Consume all remaining data from the pipes until they are closed
+          #
+          stdout_write.close
+          stderr_write.close
+
+          while consume_output(open_streams, stdout_read, stderr_read)
+          end
+        end
+      end
+
+      private
+
+      class ThingThatLooksSortOfLikeAProcessStatus
+        attr_accessor :exitstatus
+      end
+
+      def consume_output(open_streams, stdout_read, stderr_read)
+        return false if open_streams.length == 0
+        ready = IO.select(open_streams, nil, nil, READ_WAIT_TIME)
+        return true if ! ready
+
+        if ready.first.include?(stdout_read)
+          begin
+            next_chunk = stdout_read.readpartial(READ_SIZE)
+            @stdout << next_chunk
+            @live_stream << next_chunk if @live_stream
+          rescue EOFError
+            stdout_read.close
+            open_streams.delete(stdout_read)
+          end
+        end
+
+        if ready.first.include?(stderr_read)
+          begin
+            @stderr << stderr_read.readpartial(READ_SIZE)
+          rescue EOFError
+            stderr_read.close
+            open_streams.delete(stderr_read)
+          end
+        end
+
+        return true
+      end
+
+      SHOULD_USE_CMD = /['"<>|&%]|\b(?:assoc|break|call|cd|chcp|chdir|cls|color|copy|ctty|date|del|dir|echo|endlocal|erase|exit|for|ftype|goto|if|lfnfor|lh|lock|md|mkdir|move|path|pause|popd|prompt|pushd|rd|rem|ren|rename|rmdir|set|setlocal|shift|start|time|title|truename|type|unlock|ver|verify|vol)\b/
+
+      def command_to_run
+        if command =~ SHOULD_USE_CMD
+          [ ENV['COMSPEC'], "cmd /c #{command}" ]
+        else
+          [ which(command[0,command.index(/\s/) || command.length]), command ]
+        end
+      end
+
+      def inherit_environment
+        result = {}
+        ENV.each_pair do |k,v|
+          result[k] = v
+        end
+
+        environment.each_pair do |k,v|
+          if v == nil
+            result.delete(k)
+          else
+            result[k] = v
+          end
+        end
+        result
+      end
+
+      def which(cmd)
+        return cmd if File.executable? cmd
+        exts = ENV['PATHEXT'] ? ENV['PATHEXT'].split(';') + [''] : ['']
+        ENV['PATH'].split(File::PATH_SEPARATOR).each do |path|
+          exts.each { |ext|
+            exe = "#{path}/#{cmd}#{ext}"
+            return exe if File.executable? exe
+          }
+        end
+        return nil
+      end
+    end # class
+  end
+end
+
+#
+# Override module Windows::Process.CreateProcess to fix bug when
+# using both app_name and command_line
+#
+module Windows
+  module Process
+    API.new('CreateProcess', 'SPPPLLLPPP', 'B')
+  end
+end
+
+#
+# Override Win32::Process.create to take a proper environment hash
+# so that variables can contain semicolons
+# (submitted patch to owner)
+#
+module Process
+  def create(args)
+    unless args.kind_of?(Hash)
+      raise TypeError, 'Expecting hash-style keyword arguments'
+    end
+      
+    valid_keys = %w/
+      app_name command_line inherit creation_flags cwd environment
+      startup_info thread_inherit process_inherit close_handles with_logon
+      domain password
+    /
+
+    valid_si_keys = %/
+      startf_flags desktop title x y x_size y_size x_count_chars
+      y_count_chars fill_attribute sw_flags stdin stdout stderr
+    /
+
+    # Set default values
+    hash = {
+      'app_name'       => nil,
+      'creation_flags' => 0,
+      'close_handles'  => true
+    }
+      
+    # Validate the keys, and convert symbols and case to lowercase strings.     
+    args.each{ |key, val|
+      key = key.to_s.downcase
+      unless valid_keys.include?(key)
+        raise ArgumentError, "invalid key '#{key}'"
+      end
+      hash[key] = val
+    }
+      
+    si_hash = {}
+      
+    # If the startup_info key is present, validate its subkeys
+    if hash['startup_info']
+      hash['startup_info'].each{ |key, val|
+        key = key.to_s.downcase
+        unless valid_si_keys.include?(key)
+          raise ArgumentError, "invalid startup_info key '#{key}'"
+        end
+        si_hash[key] = val
+      }
+    end
+
+    # The +command_line+ key is mandatory unless the +app_name+ key
+    # is specified.
+    unless hash['command_line']
+      if hash['app_name']
+        hash['command_line'] = hash['app_name']
+        hash['app_name'] = nil
+      else
+        raise ArgumentError, 'command_line or app_name must be specified'
+      end
+    end
+      
+    # The environment string should be passed as an array of A=B paths, or
+    # as a string of ';' separated paths.
+    if hash['environment']
+      env = hash['environment']
+      if !env.respond_to?(:join)
+        # Backwards compat for ; separated paths
+        env = hash['environment'].split(File::PATH_SEPARATOR)
+      end
+      # The argument format is a series of null-terminated strings, with an additional null terminator.
+      env = env.map { |e| e + "\0" }.join("") + "\0"
+      if hash['with_logon']
+        env = env.multi_to_wide(e)
+      end
+      env = [env].pack('p*').unpack('L').first
+    else
+      env = nil
+    end
+
+    startinfo = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
+    startinfo = startinfo.pack('LLLLLLLLLLLLSSLLLL')
+    procinfo  = [0,0,0,0].pack('LLLL')
+
+    # Process SECURITY_ATTRIBUTE structure
+    process_security = 0
+    if hash['process_inherit']
+      process_security = [0,0,0].pack('LLL')
+      process_security[0,4] = [12].pack('L') # sizeof(SECURITY_ATTRIBUTE)
+      process_security[8,4] = [1].pack('L')  # TRUE
+    end
+
+    # Thread SECURITY_ATTRIBUTE structure
+    thread_security = 0
+    if hash['thread_inherit']
+      thread_security = [0,0,0].pack('LLL')
+      thread_security[0,4] = [12].pack('L') # sizeof(SECURITY_ATTRIBUTE)
+      thread_security[8,4] = [1].pack('L')  # TRUE
+    end
+
+    # Automatically handle stdin, stdout and stderr as either IO objects
+    # or file descriptors.  This won't work for StringIO, however.
+    ['stdin', 'stdout', 'stderr'].each{ |io|
+      if si_hash[io]
+        if si_hash[io].respond_to?(:fileno)
+          handle = get_osfhandle(si_hash[io].fileno)
+        else
+          handle = get_osfhandle(si_hash[io])
+        end
+            
+        if handle == INVALID_HANDLE_VALUE
+          raise Error, get_last_error
+        end
+
+        # Most implementations of Ruby on Windows create inheritable
+        # handles by default, but some do not. RF bug #26988.
+        bool = SetHandleInformation(
+          handle,
+          HANDLE_FLAG_INHERIT,
+          HANDLE_FLAG_INHERIT
+        )
+
+        raise Error, get_last_error unless bool
+            
+        si_hash[io] = handle
+        si_hash['startf_flags'] ||= 0
+        si_hash['startf_flags'] |= STARTF_USESTDHANDLES
+        hash['inherit'] = true
+      end
+    }
+      
+    # The bytes not covered here are reserved (null)
+    unless si_hash.empty?
+      startinfo[0,4]  = [startinfo.size].pack('L')
+      startinfo[8,4]  = [si_hash['desktop']].pack('p*') if si_hash['desktop']
+      startinfo[12,4] = [si_hash['title']].pack('p*') if si_hash['title']
+      startinfo[16,4] = [si_hash['x']].pack('L') if si_hash['x']
+      startinfo[20,4] = [si_hash['y']].pack('L') if si_hash['y']
+      startinfo[24,4] = [si_hash['x_size']].pack('L') if si_hash['x_size']
+      startinfo[28,4] = [si_hash['y_size']].pack('L') if si_hash['y_size']
+      startinfo[32,4] = [si_hash['x_count_chars']].pack('L') if si_hash['x_count_chars']
+      startinfo[36,4] = [si_hash['y_count_chars']].pack('L') if si_hash['y_count_chars']
+      startinfo[40,4] = [si_hash['fill_attribute']].pack('L') if si_hash['fill_attribute']
+      startinfo[44,4] = [si_hash['startf_flags']].pack('L') if si_hash['startf_flags']
+      startinfo[48,2] = [si_hash['sw_flags']].pack('S') if si_hash['sw_flags']
+      startinfo[56,4] = [si_hash['stdin']].pack('L') if si_hash['stdin']
+      startinfo[60,4] = [si_hash['stdout']].pack('L') if si_hash['stdout']
+      startinfo[64,4] = [si_hash['stderr']].pack('L') if si_hash['stderr']        
+    end
+
+    if hash['with_logon']
+      logon  = multi_to_wide(hash['with_logon'])
+      domain = multi_to_wide(hash['domain'])
+      app    = hash['app_name'].nil? ? nil : multi_to_wide(hash['app_name'])
+      cmd    = hash['command_line'].nil? ? nil : multi_to_wide(hash['command_line'])
+      cwd    = multi_to_wide(hash['cwd'])
+      passwd = multi_to_wide(hash['password'])
+         
+      hash['creation_flags'] |= CREATE_UNICODE_ENVIRONMENT
+
+      process_ran = CreateProcessWithLogonW(
+        logon,                  # User
+        domain,                 # Domain
+        passwd,                 # Password
+        LOGON_WITH_PROFILE,     # Logon flags
+        app,                    # App name
+        cmd,                    # Command line
+        hash['creation_flags'], # Creation flags
+        env,                    # Environment
+        cwd,                    # Working directory
+        startinfo,              # Startup Info
+        procinfo                # Process Info
+      )
+    else     
+      process_ran = CreateProcess(
+        hash['app_name'],       # App name
+        hash['command_line'],   # Command line
+        process_security,       # Process attributes
+        thread_security,        # Thread attributes
+        hash['inherit'],        # Inherit handles?
+        hash['creation_flags'], # Creation flags
+        env,                    # Environment
+        hash['cwd'],            # Working directory
+        startinfo,              # Startup Info
+        procinfo                # Process Info
+      )
+    end      
+
+    # TODO: Close stdin, stdout and stderr handles in the si_hash unless
+    # they're pointing to one of the standard handles already. [Maybe]
+    if !process_ran
+      raise_last_error("CreateProcess()")
+    end
+      
+    # Automatically close the process and thread handles in the
+    # PROCESS_INFORMATION struct unless explicitly told not to.
+    if hash['close_handles']
+      CloseHandle(procinfo[0,4].unpack('L').first)
+      CloseHandle(procinfo[4,4].unpack('L').first)
+    end      
+      
+    ProcessInfo.new(
+      procinfo[0,4].unpack('L').first, # hProcess
+      procinfo[4,4].unpack('L').first, # hThread
+      procinfo[8,4].unpack('L').first, # hProcessId
+      procinfo[12,4].unpack('L').first # hThreadId
+    )
+  end
+
+  def self.raise_last_error(operation)
+    error_string = "#{operation} failed: #{get_last_error}"
+    last_error_code = GetLastError()
+    if ERROR_CODE_MAP.has_key?(last_error_code)
+      raise ERROR_CODE_MAP[last_error_code], error_string
+    else
+      raise Error, error_string
+    end
+  end
+
+  # List from ruby/win32/win32.c
+  ERROR_CODE_MAP = {
+    ERROR_INVALID_FUNCTION => Errno::EINVAL,
+    ERROR_FILE_NOT_FOUND => Errno::ENOENT,
+    ERROR_PATH_NOT_FOUND => Errno::ENOENT,
+    ERROR_TOO_MANY_OPEN_FILES => Errno::EMFILE,
+    ERROR_ACCESS_DENIED => Errno::EACCES,
+    ERROR_INVALID_HANDLE => Errno::EBADF,
+    ERROR_ARENA_TRASHED => Errno::ENOMEM,
+    ERROR_NOT_ENOUGH_MEMORY => Errno::ENOMEM,
+    ERROR_INVALID_BLOCK => Errno::ENOMEM,
+    ERROR_BAD_ENVIRONMENT => Errno::E2BIG,
+    ERROR_BAD_FORMAT => Errno::ENOEXEC,
+    ERROR_INVALID_ACCESS => Errno::EINVAL,
+    ERROR_INVALID_DATA => Errno::EINVAL,
+    ERROR_INVALID_DRIVE => Errno::ENOENT,
+    ERROR_CURRENT_DIRECTORY => Errno::EACCES,
+    ERROR_NOT_SAME_DEVICE => Errno::EXDEV,
+    ERROR_NO_MORE_FILES => Errno::ENOENT,
+    ERROR_WRITE_PROTECT => Errno::EROFS,
+    ERROR_BAD_UNIT => Errno::ENODEV,
+    ERROR_NOT_READY => Errno::ENXIO,
+    ERROR_BAD_COMMAND => Errno::EACCES,
+    ERROR_CRC => Errno::EACCES,
+    ERROR_BAD_LENGTH => Errno::EACCES,
+    ERROR_SEEK => Errno::EIO,
+    ERROR_NOT_DOS_DISK => Errno::EACCES,
+    ERROR_SECTOR_NOT_FOUND => Errno::EACCES,
+    ERROR_OUT_OF_PAPER => Errno::EACCES,
+    ERROR_WRITE_FAULT => Errno::EIO,
+    ERROR_READ_FAULT => Errno::EIO,
+    ERROR_GEN_FAILURE => Errno::EACCES,
+    ERROR_LOCK_VIOLATION => Errno::EACCES,
+    ERROR_SHARING_VIOLATION => Errno::EACCES,
+    ERROR_WRONG_DISK => Errno::EACCES,
+    ERROR_SHARING_BUFFER_EXCEEDED => Errno::EACCES,
+#    ERROR_BAD_NETPATH => Errno::ENOENT,
+#    ERROR_NETWORK_ACCESS_DENIED => Errno::EACCES,
+#    ERROR_BAD_NET_NAME => Errno::ENOENT,
+    ERROR_FILE_EXISTS => Errno::EEXIST,
+    ERROR_CANNOT_MAKE => Errno::EACCES,
+    ERROR_FAIL_I24 => Errno::EACCES,
+    ERROR_INVALID_PARAMETER => Errno::EINVAL,
+    ERROR_NO_PROC_SLOTS => Errno::EAGAIN,
+    ERROR_DRIVE_LOCKED => Errno::EACCES,
+    ERROR_BROKEN_PIPE => Errno::EPIPE,
+    ERROR_DISK_FULL => Errno::ENOSPC,
+    ERROR_INVALID_TARGET_HANDLE => Errno::EBADF,
+    ERROR_INVALID_HANDLE => Errno::EINVAL,
+    ERROR_WAIT_NO_CHILDREN => Errno::ECHILD,
+    ERROR_CHILD_NOT_COMPLETE => Errno::ECHILD,
+    ERROR_DIRECT_ACCESS_HANDLE => Errno::EBADF,
+    ERROR_NEGATIVE_SEEK => Errno::EINVAL,
+    ERROR_SEEK_ON_DEVICE => Errno::EACCES,
+    ERROR_DIR_NOT_EMPTY => Errno::ENOTEMPTY,
+#    ERROR_DIRECTORY => Errno::ENOTDIR,
+    ERROR_NOT_LOCKED => Errno::EACCES,
+    ERROR_BAD_PATHNAME => Errno::ENOENT,
+    ERROR_MAX_THRDS_REACHED => Errno::EAGAIN,
+#    ERROR_LOCK_FAILED => Errno::EACCES,
+    ERROR_ALREADY_EXISTS => Errno::EEXIST,
+    ERROR_INVALID_STARTING_CODESEG => Errno::ENOEXEC,
+    ERROR_INVALID_STACKSEG => Errno::ENOEXEC,
+    ERROR_INVALID_MODULETYPE => Errno::ENOEXEC,
+    ERROR_INVALID_EXE_SIGNATURE => Errno::ENOEXEC,
+    ERROR_EXE_MARKED_INVALID => Errno::ENOEXEC,
+    ERROR_BAD_EXE_FORMAT => Errno::ENOEXEC,
+    ERROR_ITERATED_DATA_EXCEEDS_64k => Errno::ENOEXEC,
+    ERROR_INVALID_MINALLOCSIZE => Errno::ENOEXEC,
+    ERROR_DYNLINK_FROM_INVALID_RING => Errno::ENOEXEC,
+    ERROR_IOPL_NOT_ENABLED => Errno::ENOEXEC,
+    ERROR_INVALID_SEGDPL => Errno::ENOEXEC,
+    ERROR_AUTODATASEG_EXCEEDS_64k => Errno::ENOEXEC,
+    ERROR_RING2SEG_MUST_BE_MOVABLE => Errno::ENOEXEC,
+    ERROR_RELOC_CHAIN_XEEDS_SEGLIM => Errno::ENOEXEC,
+    ERROR_INFLOOP_IN_RELOC_CHAIN => Errno::ENOEXEC,
+    ERROR_FILENAME_EXCED_RANGE => Errno::ENOENT,
+    ERROR_NESTING_NOT_ALLOWED => Errno::EAGAIN,
+#    ERROR_PIPE_LOCAL => Errno::EPIPE,
+    ERROR_BAD_PIPE => Errno::EPIPE,
+    ERROR_PIPE_BUSY => Errno::EAGAIN,
+    ERROR_NO_DATA => Errno::EPIPE,
+    ERROR_PIPE_NOT_CONNECTED => Errno::EPIPE,
+    ERROR_OPERATION_ABORTED => Errno::EINTR,
+#    ERROR_NOT_ENOUGH_QUOTA => Errno::ENOMEM,
+    ERROR_MOD_NOT_FOUND => Errno::ENOENT,
+    WSAEINTR => Errno::EINTR,
+    WSAEBADF => Errno::EBADF,
+#    WSAEACCES => Errno::EACCES,
+    WSAEFAULT => Errno::EFAULT,
+    WSAEINVAL => Errno::EINVAL,
+    WSAEMFILE => Errno::EMFILE,
+    WSAEWOULDBLOCK => Errno::EWOULDBLOCK,
+    WSAEINPROGRESS => Errno::EINPROGRESS,
+    WSAEALREADY => Errno::EALREADY,
+    WSAENOTSOCK => Errno::ENOTSOCK,
+    WSAEDESTADDRREQ => Errno::EDESTADDRREQ,
+    WSAEMSGSIZE => Errno::EMSGSIZE,
+    WSAEPROTOTYPE => Errno::EPROTOTYPE,
+    WSAENOPROTOOPT => Errno::ENOPROTOOPT,
+    WSAEPROTONOSUPPORT => Errno::EPROTONOSUPPORT,
+    WSAESOCKTNOSUPPORT => Errno::ESOCKTNOSUPPORT,
+    WSAEOPNOTSUPP => Errno::EOPNOTSUPP,
+    WSAEPFNOSUPPORT => Errno::EPFNOSUPPORT,
+    WSAEAFNOSUPPORT => Errno::EAFNOSUPPORT,
+    WSAEADDRINUSE => Errno::EADDRINUSE,
+    WSAEADDRNOTAVAIL => Errno::EADDRNOTAVAIL,
+    WSAENETDOWN => Errno::ENETDOWN,
+    WSAENETUNREACH => Errno::ENETUNREACH,
+    WSAENETRESET => Errno::ENETRESET,
+    WSAECONNABORTED => Errno::ECONNABORTED,
+    WSAECONNRESET => Errno::ECONNRESET,
+    WSAENOBUFS => Errno::ENOBUFS,
+    WSAEISCONN => Errno::EISCONN,
+    WSAENOTCONN => Errno::ENOTCONN,
+    WSAESHUTDOWN => Errno::ESHUTDOWN,
+    WSAETOOMANYREFS => Errno::ETOOMANYREFS,
+#    WSAETIMEDOUT => Errno::ETIMEDOUT,
+    WSAECONNREFUSED => Errno::ECONNREFUSED,
+    WSAELOOP => Errno::ELOOP,
+    WSAENAMETOOLONG => Errno::ENAMETOOLONG,
+    WSAEHOSTDOWN => Errno::EHOSTDOWN,
+    WSAEHOSTUNREACH => Errno::EHOSTUNREACH,
+#    WSAEPROCLIM => Errno::EPROCLIM,
+#    WSAENOTEMPTY => Errno::ENOTEMPTY,
+    WSAEUSERS => Errno::EUSERS,
+    WSAEDQUOT => Errno::EDQUOT,
+    WSAESTALE => Errno::ESTALE,
+    WSAEREMOTE => Errno::EREMOTE
+  }
+
+  module_function :create
+end