lib/shell/system-command.rb

   1 #
   2 #   shell/system-command.rb -
   3 #       $Release Version: 0.7 $
   4 #       $Revision$
   5 #       by Keiju ISHITSUKA(keiju@ruby-lang.org)
   6 #
   7 # --
   8 #
   9 #
  10 #
  11
  12 require "shell/filter"
  13
  14 class Shell
  15   class SystemCommand < Filter
  16     def initialize(sh, command, *opts)
  17       if t = opts.find{|opt| !opt.kind_of?(String) && opt.class}
  18         Shell.Fail Error::TypeError, t.class, "String"
  19       end
  20       super(sh)
  21       @command = command
  22       @opts = opts
  23
  24       @input_queue = Queue.new
  25       @pid = nil
  26
  27       sh.process_controller.add_schedule(self)
  28     end
  29
  30     attr_reader :command
  31     alias name command
  32
  33     def wait?
  34       @shell.process_controller.waiting_job?(self)
  35     end
  36
  37     def active?
  38       @shell.process_controller.active_job?(self)
  39     end
  40
  41     def input=(inp)
  42       super
  43       if active?
  44         start_export
  45       end
  46     end
  47
  48     def start
  49       notify([@command, *@opts].join(" "))
  50
  51       @pid, @pipe_in, @pipe_out = @shell.process_controller.sfork(self) {
  52         Dir.chdir @shell.pwd
  53         $0 = @command
  54         exec(@command, *@opts)
  55       }
  56       if @input
  57         start_export
  58       end
  59       start_import
  60     end
  61
  62     def flush
  63       @pipe_out.flush if @pipe_out and !@pipe_out.closed?
  64     end
  65
  66     def terminate
  67       begin
  68         @pipe_in.close
  69       rescue IOError
  70       end
  71       begin
  72         @pipe_out.close
  73       rescue IOError
  74       end
  75     end
  76
  77     def kill(sig)
  78       if @pid
  79         Process.kill(sig, @pid)
  80       end
  81     end
  82
  83     def start_import
  84       notify "Job(%id) start imp-pipe.", @shell.debug?
  85       rs = @shell.record_separator unless rs
  86       _eop = true
  87       th = Thread.start {
  88         begin
  89           while l = @pipe_in.gets
  90             @input_queue.push l
  91           end
  92           _eop = false
  93         rescue Errno::EPIPE
  94           _eop = false
  95         ensure
  96           if !ProcessController::USING_AT_EXIT_WHEN_PROCESS_EXIT and _eop
  97             notify("warn: Process finishing...",
  98                    "wait for Job[%id] to finish pipe importing.",
  99                    "You can use Shell#transact or Shell#check_point for more safe execution.")
 100             redo
 101           end
 102           notify "job(%id}) close imp-pipe.", @shell.debug?
 103           @input_queue.push :EOF
 104           @pipe_in.close
 105         end
 106       }
 107     end
 108
 109     def start_export
 110       notify "job(%id) start exp-pipe.", @shell.debug?
 111       _eop = true
 112       th = Thread.start{
 113         begin
 114           @input.each do |l|
 115             ProcessController::block_output_synchronize do
 116               @pipe_out.print l
 117             end
 118           end
 119           _eop = false
 120         rescue Errno::EPIPE, Errno::EIO
 121           _eop = false
 122         ensure
 123           if !ProcessController::USING_AT_EXIT_WHEN_PROCESS_EXIT and _eop
 124             notify("shell: warn: Process finishing...",
 125                    "wait for Job(%id) to finish pipe exporting.",
 126                    "You can use Shell#transact or Shell#check_point for more safe execution.")
 127             redo
 128           end
 129           notify "job(%id) close exp-pipe.", @shell.debug?
 130           @pipe_out.close
 131         end
 132       }
 133     end
 134
 135     alias super_each each
 136     def each(rs = nil)
 137       while (l = @input_queue.pop) != :EOF
 138         yield l
 139       end
 140     end
 141
 142     # ex)
 143     #    if you wish to output:
 144     #       "shell: job(#{@command}:#{@pid}) close pipe-out."
 145     #    then
 146     #       mes: "job(%id) close pipe-out."
 147     #    yorn: Boolean(@shell.debug? or @shell.verbose?)
 148     def notify(*opts, &block)
 149       @shell.notify(*opts) do |mes|
 150         yield mes if iterator?
 151
 152         mes.gsub!("%id", "#{@command}:##{@pid}")
 153         mes.gsub!("%name", "#{@command}")
 154         mes.gsub!("%pid", "#{@pid}")
 155         mes
 156       end
 157     end
 158   end
 159 end