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#
# = open3.rb: Popen, but with stderr, too
#
# Author:: Yukihiro Matsumoto
# Documentation:: Konrad Meyer
#
# Open3 gives you access to stdin, stdout, and stderr when running other
# programs.
#

#
# Open3 grants you access to stdin, stdout, stderr and a thread to wait the
# child process when running another program.
# You can specify various attributes, redirections, current directory, etc., of
# the program as Process.spawn.
#
# - Open3.popen3 : pipes for stdin, stdout, stderr
# - Open3.popen2 : pipes for stdin, stdout
# - Open3.popen2e : pipes for stdin, merged stdout and stderr
# - Open3.capture3 : give a string for stdin. get strings for stdout, stderr
# - Open3.capture2 : give a string for stdin. get a string for stdout
# - Open3.capture2e : give a string for stdin. get a string for merged stdout and stderr
# - Open3.pipeline_rw : pipes for first stdin and last stdout of a pipeline
# - Open3.pipeline_r : pipe for last stdout of a pipeline
# - Open3.pipeline_w : pipe for first stdin of a pipeline
# - Open3.pipeline_start : a pipeline
# - Open3.pipeline : run a pipline and wait
#

module Open3

  # Open stdin, stdout, and stderr streams and start external executable.
  # In addition, a thread for waiting the started process is noticed.
  # The thread has a pid method and thread variable :pid which is the pid of
  # the started process.
  #
  # Block form:
  #
  # Open3.popen3([env,] cmd... [, opts]) {|stdin, stdout, stderr, wait_thr|
  # pid = wait_thr.pid # pid of the started process.
  # ...
  # exit_status = wait_thr.value # Process::Status object returned.
  # }
  #
  # Non-block form:
  #
  # stdin, stdout, stderr, wait_thr = Open3.popen3([env,] cmd... [, opts])
  # pid = wait_thr[:pid] # pid of the started process.
  # ...
  # stdin.close # stdin, stdout and stderr should be closed explicitly in this form.
  # stdout.close
  # stderr.close
  # exit_status = wait_thr.value # Process::Status object returned.
  #
  # The parameters +cmd...+ is passed to Process.spawn.
  # So a commandline string and list of argument strings can be accepted as follows.
  #
  # Open3.popen3("echo a") {|i, o, e, t| ... }
  # Open3.popen3("echo", "a") {|i, o, e, t| ... }
  # Open3.popen3(["echo", "argv0"], "a") {|i, o, e, t| ... }
  #
  # If the last parameter, opts, is a Hash, it is recognized as an option for Process.spawn.
  #
  # Open3.popen3("pwd", :chdir=>"/") {|i,o,e,t|
  # p o.read.chomp #=> "/"
  # }
  #
  # wait_thr.value waits the termination of the process.
  # The block form also waits the process when it returns.
  #
  # Closing stdin, stdout and stderr does not wait the process.
  #
  def popen3(*cmd, &block)
    if Hash === cmd.last
      opts = cmd.pop.dup
    else
      opts = {}
    end

    in_r, in_w = IO.pipe
    opts[:in] = in_r
    in_w.sync = true

    out_r, out_w = IO.pipe
    opts[:out] = out_w

    err_r, err_w = IO.pipe
    opts[:err] = err_w

    popen_run(cmd, opts, [in_r, out_w, err_w], [in_w, out_r, err_r], &block)
  end
  module_function :popen3

  # Open3.popen2 is similer to Open3.popen3 except it doesn't make a pipe for
  # the standard error stream.
  #
  # Block form:
  #
  # Open3.popen2([env,] cmd... [, opts]) {|stdin, stdout, wait_thr|
  # pid = wait_thr.pid # pid of the started process.
  # ...
  # exit_status = wait_thr.value # Process::Status object returned.
  # }
  #
  # Non-block form:
  #
  # stdin, stdout, wait_thr = Open3.popen2([env,] cmd... [, opts])
  # ...
  # stdin.close # stdin and stdout should be closed explicitly in this form.
  # stdout.close
  #
  # See Process.spawn for the optional hash arguments _env_ and _opts_.
  #
  # Example:
  #
  # Open3.popen2("wc -c") {|i,o,t|
  # i.print "answer to life the universe and everything"
  # i.close
  # p o.gets #=> "42\n"
  # }
  #
  # Open3.popen2("bc -q") {|i,o,t|
  # i.puts "obase=13"
  # i.puts "6 * 9"
  # p o.gets #=> "42\n"
  # }
  #
  # Open3.popen2("dc") {|i,o,t|
  # i.print "42P"
  # i.close
  # p o.read #=> "*"
  # }
  #
  def popen2(*cmd, &block)
    if Hash === cmd.last
      opts = cmd.pop.dup
    else
      opts = {}
    end

    in_r, in_w = IO.pipe
    opts[:in] = in_r
    in_w.sync = true

    out_r, out_w = IO.pipe
    opts[:out] = out_w

    popen_run(cmd, opts, [in_r, out_w], [in_w, out_r], &block)
  end
  module_function :popen2

  # Open3.popen2e is similer to Open3.popen3 except it merges
  # the standard output stream and the standard error stream.
  #
  # Block form:
  #
  # Open3.popen2e([env,] cmd... [, opts]) {|stdin, stdout_and_stderr, wait_thr|
  # pid = wait_thr.pid # pid of the started process.
  # ...
  # exit_status = wait_thr.value # Process::Status object returned.
  # }
  #
  # Non-block form:
  #
  # stdin, stdout_and_stderr, wait_thr = Open3.popen2e([env,] cmd... [, opts])
  # ...
  # stdin.close # stdin and stdout_and_stderr should be closed explicitly in this form.
  # stdout_and_stderr.close
  #
  # See Process.spawn for the optional hash arguments _env_ and _opts_.
  #
  # Example:
  # # check gcc warnings
  # source = "foo.c"
  # Open3.popen2e("gcc", "-Wall", source) {|i,oe,t|
  # oe.each {|line|
  # if /warning/ =~ line
  # ...
  # end
  # }
  # }
  #
  def popen2e(*cmd, &block)
    if Hash === cmd.last
      opts = cmd.pop.dup
    else
      opts = {}
    end

    in_r, in_w = IO.pipe
    opts[:in] = in_r
    in_w.sync = true

    out_r, out_w = IO.pipe
    opts[[:out, :err]] = out_w

    popen_run(cmd, opts, [in_r, out_w], [in_w, out_r], &block)
  end
  module_function :popen2e

  def popen_run(cmd, opts, child_io, parent_io) # :nodoc:
    pid = spawn(*cmd, opts)
    wait_thr = Process.detach(pid)
    child_io.each {|io| io.close }
    result = [*parent_io, wait_thr]
    if defined? yield
      begin
return yield(*result)
      ensure
parent_io.each{|io| io.close unless io.closed?}
        wait_thr.join
      end
    end
    result
  end
  module_function :popen_run
  class << self
    private :popen_run
  end

  # Open3.capture3 captures the standard output and the standard error of a command.
  #
  # stdout_str, stderr_str, status = Open3.capture3([env,] cmd... [, opts])
  #
  # The arguments env, cmd and opts are passed to Open3.popen3 except
  # opts[:stdin_data] and opts[:stdin_data]. See Process.spawn.
  #
  # If opts[:stdin_data] is specified, it is sent to the command's standard input.
  #
  # If opts[:binmode] is true, internal pipes are set to binary mode.
  #
  # Example:
  #
  # # dot is a command of graphviz.
  # graph = <<'End'
  # digraph g {
  # a -> b
  # }
  # End
  # layouted_graph, dot_log = Open3.capture3("dot -v", :stdin_data=>graph)
  #
  # o, e, s = Open3.capture3("echo a; sort >&2", :stdin_data=>"foo\nbar\nbaz\n")
  # p o #=> "a\n"
  # p e #=> "bar\nbaz\nfoo\n"
  # p s #=> #<Process::Status: pid 32682 exit 0>
  #
  # # generate a thumnail image using the convert command of ImageMagick.
  # # However, if the image stored really in a file,
  # # system("convert", "-thumbnail", "80", "png:#{filename}", "png:-") is better
  # # because memory consumption.
  # # But if the image is stored in a DB or generated by gnuplot Open3.capture2 example,
  # # Open3.capture3 is considerable.
  # #
  # image = File.read("/usr/share/openclipart/png/animals/mammals/sheep-md-v0.1.png", :binmode=>true)
  # thumnail, err, s = Open3.capture3("convert -thumbnail 80 png:- png:-", :stdin_data=>image, :binmode=>true)
  # if s.success?
  # STDOUT.binmode; print thumnail
  # end
  #
  def capture3(*cmd, &block)
    if Hash === cmd.last
      opts = cmd.pop.dup
    else
      opts = {}
    end

    stdin_data = opts.delete(:stdin_data) || ''
    binmode = opts.delete(:binmode)

    popen3(*cmd, opts) {|i, o, e, t|
      if binmode
        i.binmode
        o.binmode
        e.binmode
      end
      out_reader = Thread.new { o.read }
      err_reader = Thread.new { e.read }
      i.write stdin_data
      i.close
      [out_reader.value, err_reader.value, t.value]
    }
  end
  module_function :capture3

  # Open3.capture2 captures the standard output of a command.
  #
  # stdout_str, status = Open3.capture2([env,] cmd... [, opts])
  #
  # The arguments env, cmd and opts are passed to Open3.popen3 except
  # opts[:stdin_data] and opts[:stdin_data]. See Process.spawn.
  #
  # If opts[:stdin_data] is specified, it is sent to the command's standard input.
  #
  # If opts[:binmode] is true, internal pipes are set to binary mode.
  #
  # Example:
  #
  # # factor is a command for integer factorization.
  # o, s = Open3.capture2("factor", :stdin_data=>"42")
  # p o #=> "42: 2 3 7\n"
  #
  # # generate x**2 graph in png using gnuplot.
  # gnuplot_commands = <<"End"
  # set terminal png
  # plot x**2, "-" with lines
  # 1 14
  # 2 1
  # 3 8
  # 4 5
  # e
  # End
  # image, s = Open3.capture2("gnuplot", :stdin_data=>gnuplot_commands, :binmode=>true)
  #
  def capture2(*cmd, &block)
    if Hash === cmd.last
      opts = cmd.pop.dup
    else
      opts = {}
    end

    stdin_data = opts.delete(:stdin_data) || ''
    binmode = opts.delete(:binmode)

    popen2(*cmd, opts) {|i, o, t|
      if binmode
        i.binmode
        o.binmode
      end
      out_reader = Thread.new { o.read }
      i.write stdin_data
      i.close
      [out_reader.value, t.value]
    }
  end
  module_function :capture2

  # Open3.capture2e captures the standard output and the standard error of a command.
  #
  # stdout_and_stderr_str, status = Open3.capture2e([env,] cmd... [, opts])
  #
  # The arguments env, cmd and opts are passed to Open3.popen3 except
  # opts[:stdin_data] and opts[:stdin_data]. See Process.spawn.
  #
  # If opts[:stdin_data] is specified, it is sent to the command's standard input.
  #
  # If opts[:binmode] is true, internal pipes are set to binary mode.
  #
  # Example:
  #
  # # capture make log
  # make_log, s = Open3.capture2e("make")
  #
  def capture2e(*cmd, &block)
    if Hash === cmd.last
      opts = cmd.pop.dup
    else
      opts = {}
    end

    stdin_data = opts.delete(:stdin_data) || ''
    binmode = opts.delete(:binmode)

    popen2e(*cmd, opts) {|i, oe, t|
      if binmode
        i.binmode
        oe.binmode
      end
      outerr_reader = Thread.new { oe.read }
      i.write stdin_data
      i.close
      [outerr_reader.value, t.value]
    }
  end
  module_function :capture2e

  # Open3.pipeline_rw starts a list of commands as a pipeline with pipes
  # which connects stdin of the first command and stdout of the last command.
  #
  # Open3.pipeline_rw(cmd1, cmd2, ... [, opts]) {|first_stdin, last_stdout, wait_threads|
  # ...
  # }
  #
  # first_stdin, last_stdout, wait_threads = Open3.pipeline_rw(cmd1, cmd2, ... [, opts])
  # ...
  # first_stdin.close
  # last_stdout.close
  #
  # Each cmd is a string or an array.
  # If it is an array, the elements are passed to Process.spawn.
  #
  # cmd:
  # commandline command line string which is passed to a shell
  # [env, commandline, opts] command line string which is passed to a shell
  # [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
  # [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
  #
  # Note that env and opts are optional, as Process.spawn.
  #
  # The option to pass Process.spawn is constructed by merging
  # +opts+, the last hash element of the array and
  # specification for the pipe between each commands.
  #
  # Example:
  #
  # Open3.pipeline_rw("tr -dc A-Za-z", "wc -c") {|i,o,ts|
  # i.puts "All persons more than a mile high to leave the court."
  # i.close
  # p o.gets #=> "42\n"
  # }
  #
  # Open3.pipeline_rw("sort", "cat -n") {|stdin, stdout, wait_thrs|
  # stdin.puts "foo"
  # stdin.puts "bar"
  # stdin.puts "baz"
  # stdin.close # send EOF to sort.
  # p stdout.read #=> " 1\tbar\n 2\tbaz\n 3\tfoo\n"
  # }
  def pipeline_rw(*cmds, &block)
    if Hash === cmds.last
      opts = cmds.pop.dup
    else
      opts = {}
    end

    in_r, in_w = IO.pipe
    opts[:in] = in_r
    in_w.sync = true

    out_r, out_w = IO.pipe
    opts[:out] = out_w

    pipeline_run(cmds, opts, [in_r, out_w], [in_w, out_r], &block)
  end
  module_function :pipeline_rw

  # Open3.pipeline_r starts a list of commands as a pipeline with a pipe
  # which connects stdout of the last command.
  #
  # Open3.pipeline_r(cmd1, cmd2, ... [, opts]) {|last_stdout, wait_threads|
  # ...
  # }
  #
  # last_stdout, wait_threads = Open3.pipeline_r(cmd1, cmd2, ... [, opts])
  # ...
  # last_stdout.close
  #
  # Each cmd is a string or an array.
  # If it is an array, the elements are passed to Process.spawn.
  #
  # cmd:
  # commandline command line string which is passed to a shell
  # [env, commandline, opts] command line string which is passed to a shell
  # [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
  # [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
  #
  # Note that env and opts are optional, as Process.spawn.
  #
  # Example:
  #
  # Open3.pipeline_r("zcat /var/log/apache2/access.log.*.gz",
  # [{"LANG"=>"C"}, "grep", "GET /favicon.ico"],
  # "logresolve") {|o, ts|
  # o.each_line {|line|
  # ...
  # }
  # }
  #
  # Open3.pipeline_r("yes", "head -10") {|o, ts|
  # p o.read #=> "y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n"
  # p ts[0].value #=> #<Process::Status: pid 24910 SIGPIPE (signal 13)>
  # p ts[1].value #=> #<Process::Status: pid 24913 exit 0>
  # }
  #
  def pipeline_r(*cmds, &block)
    if Hash === cmds.last
      opts = cmds.pop.dup
    else
      opts = {}
    end

    out_r, out_w = IO.pipe
    opts[:out] = out_w

    pipeline_run(cmds, opts, [out_w], [out_r], &block)
  end
  module_function :pipeline_r

  # Open3.pipeline_w starts a list of commands as a pipeline with a pipe
  # which connects stdin of the first command.
  #
  # Open3.pipeline_w(cmd1, cmd2, ... [, opts]) {|first_stdin, wait_threads|
  # ...
  # }
  #
  # first_stdin, wait_threads = Open3.pipeline_w(cmd1, cmd2, ... [, opts])
  # ...
  # first_stdin.close
  #
  # Each cmd is a string or an array.
  # If it is an array, the elements are passed to Process.spawn.
  #
  # cmd:
  # commandline command line string which is passed to a shell
  # [env, commandline, opts] command line string which is passed to a shell
  # [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
  # [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
  #
  # Note that env and opts are optional, as Process.spawn.
  #
  # Example:
  #
  # Open3.pipeline_w("bzip2 -c", :out=>"/tmp/hello.bz2") {|i, ts|
  # i.puts "hello"
  # }
  #
  def pipeline_w(*cmds, &block)
    if Hash === cmds.last
      opts = cmds.pop.dup
    else
      opts = {}
    end

    in_r, in_w = IO.pipe
    opts[:in] = in_r
    in_w.sync = true

    pipeline_run(cmds, opts, [in_r], [in_w], &block)
  end
  module_function :pipeline_w

  # Open3.pipeline_start starts a list of commands as a pipeline.
  # No pipe made for stdin of the first command and
  # stdout of the last command.
  #
  # Open3.pipeline_start(cmd1, cmd2, ... [, opts]) {|wait_threads|
  # ...
  # }
  #
  # wait_threads = Open3.pipeline_start(cmd1, cmd2, ... [, opts])
  # ...
  #
  # Each cmd is a string or an array.
  # If it is an array, the elements are passed to Process.spawn.
  #
  # cmd:
  # commandline command line string which is passed to a shell
  # [env, commandline, opts] command line string which is passed to a shell
  # [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
  # [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
  #
  # Note that env and opts are optional, as Process.spawn.
  #
  # Example:
  #
  # # run xeyes in 10 seconds.
  # Open3.pipeline_start("xeyes") {|ts|
  # sleep 10
  # t = ts[0]
  # Process.kill("TERM", t.pid)
  # p t.value #=> #<Process::Status: pid 911 SIGTERM (signal 15)>
  # }
  #
  # # convert pdf to ps and send it to a printer.
  # # collect error message of pdftops and lpr.
  # pdf_file = "paper.pdf"
  # printer = "printer-name"
  # err_r, err_w = IO.pipe
  # Open3.pipeline_start(["pdftops", pdf_file, "-"],
  # ["lpr", "-P#{printer}"],
  # :err=>err_w) {|ts|
  # err_w.close
  # p err_r.read # error messages of pdftops and lpr.
  # }
  #
  def pipeline_start(*cmds, &block)
    if Hash === cmds.last
      opts = cmds.pop.dup
    else
      opts = {}
    end

    if block
      pipeline_run(cmds, opts, [], [], &block)
    else
      ts, = pipeline_run(cmds, opts, [], [])
      ts
    end
  end
  module_function :pipeline_start

  # Open3.pipeline starts a list of commands as a pipeline.
  # It waits the finish of the commands.
  # No pipe made for stdin of the first command and
  # stdout of the last command.
  #
  # status_list = Open3.pipeline(cmd1, cmd2, ... [, opts])
  #
  # Each cmd is a string or an array.
  # If it is an array, the elements are passed to Process.spawn.
  #
  # cmd:
  # commandline command line string which is passed to a shell
  # [env, commandline, opts] command line string which is passed to a shell
  # [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
  # [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
  #
  # Note that env and opts are optional, as Process.spawn.
  #
  # Example:
  #
  # fname = "/usr/share/man/man1/ruby.1.gz"
  # p Open3.pipeline(["zcat", fname], "nroff -man", "less")
  # #=> [#<Process::Status: pid 11817 exit 0>,
  # # #<Process::Status: pid 11820 exit 0>,
  # # #<Process::Status: pid 11828 exit 0>]
  #
  # fname = "/usr/share/man/man1/ls.1.gz"
  # Open3.pipeline(["zcat", fname], "nroff -man", "colcrt")
  #
  # # convert PDF to PS and send to a printer by lpr
  # pdf_file = "paper.pdf"
  # printer = "printer-name"
  # Open3.pipeline(["pdftops", pdf_file, "-"],
  # ["lpr", "-P#{printer}"])
  #
  # # count lines
  # Open3.pipeline("sort", "uniq -c", :in=>"names.txt", :out=>"count")
  #
  # # cyclic pipeline
  # r,w = IO.pipe
  # w.print "ibase=14\n10\n"
  # Open3.pipeline("bc", "tee /dev/tty", :in=>r, :out=>w)
  # #=> 14
  # # 18
  # # 22
  # # 30
  # # 42
  # # 58
  # # 78
  # # 106
  # # 202
  #
  def pipeline(*cmds)
    if Hash === cmds.last
      opts = cmds.pop.dup
    else
      opts = {}
    end

    pipeline_run(cmds, opts, [], []) {|ts|
      ts.map {|t| t.value }
    }
  end
  module_function :pipeline

  def pipeline_run(cmds, pipeline_opts, child_io, parent_io, &block) # :nodoc:
    if cmds.empty?
      raise ArgumentError, "no commands"
    end

    opts_base = pipeline_opts.dup
    opts_base.delete :in
    opts_base.delete :out

    wait_thrs = []
    r = nil
    cmds.each_with_index {|cmd, i|
      cmd_opts = opts_base.dup
      if String === cmd
        cmd = [cmd]
      else
        cmd_opts.update cmd.pop if Hash === cmd.last
      end
      if i == 0
        if !cmd_opts.include?(:in)
          if pipeline_opts.include?(:in)
            cmd_opts[:in] = pipeline_opts[:in]
          end
        end
      else
        cmd_opts[:in] = r
      end
      if i != cmds.length - 1
        r2, w2 = IO.pipe
        cmd_opts[:out] = w2
      else
        if !cmd_opts.include?(:out)
          if pipeline_opts.include?(:out)
            cmd_opts[:out] = pipeline_opts[:out]
          end
        end
      end
      pid = spawn(*cmd, cmd_opts)
      wait_thrs << Process.detach(pid)
      r.close if r
      w2.close if w2
      r = r2
    }
    result = parent_io + [wait_thrs]
    child_io.each {|io| io.close }
    if defined? yield
      begin
return yield(*result)
      ensure
parent_io.each{|io| io.close unless io.closed?}
        wait_thrs.each {|t| t.join }
      end
    end
    result
  end
  module_function :pipeline_run
  class << self
    private :pipeline_run
  end

end

if $0 == __FILE__
  a = Open3.popen3("nroff -man")
  Thread.start do
    while line = gets
      a[0].print line
    end
    a[0].close
  end
  while line = a[1].gets
    print ":", line
  end
end
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