From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2004-03-28T02:44:30+09:00
Subject: mkfifo on windows


windoze types-

i have a ruby module, spawn (like popen3 w/o a fork), that relies on a system
call to 'mkfifo'.  currenlty i'm just using a system call because just about
any system with for should also have a 'mkfifo' call.  i'm considering making
this a c extension but am unsure if windows has a posix compliant mkfifo call?
i realize this is slightly off topic but the spawn method is really useful and
seems to be quite a bit faster than popen3 as well.

thanks

-a

btw.  here is the 'baby' code for Spawn:

#!/usr/bin/env ruby
require 'open3'
require 'tmpdir'
require 'io/wait'

$VERBOSE=nil

module Spawn
  class << self
    def spawn cmd
      ipath, opath, epath = tmpfifo, tmpfifo, tmpfifo
      system "#{ cmd } < #{ ipath } 1> #{ opath } 2> #{ epath } &"
      [open(ipath, 'w'), open(opath, 'r'), open(epath, 'r')]
    end
    def tmpfifo
      path = nil
      42.times do |i|
        tpath = File.join(Dir.tmpdir, "#{ $$ }.#{ rand }.#{ i }")
        system "mkfifo #{ tpath }"     # how to do this in windows, C or shell?
        next unless $? == 0
        path = tpath
        at_exit{ File.unlink(path) rescue STDERR.puts("rm <#{ path }> failed") }
        break
      end
      raise "could not generate tmpfifo" unless path
      path
    end
  end
end


if $0 == __FILE__
mode = ARGV.shift || 'open3'

program = <<-stmts
  echo 42
  sleep 1
  echo 42
  sleep 1
  echo __done__         # signals end of stdout
  echo __done__ 1>&2    # signals end of stderr
stmts

done = %r/^\s*__done__\s*$/o

thread =
  Thread.new do 
    i,o,e = (mode =~ /open3/io ?  Open3::popen3('sh') : Spawn::spawn('sh'))

    Thread.new do
      Thread.new do
        program.each{|stmt| i.puts stmt}
        i.flush
      end.join
    end

    rfds = [o,e]
    loop do
      break if rfds.empty?
      rs, = select rfds, nil, nil
      rs.each do |r|
        rfds.delete(r) and next if r.eof?
        line = ''
        line << r.getc while r.ready? 
        rfds.delete(r) and line[done]='' if line =~ done 
        next if line.empty?
        printf "%s @ %s: %s\n", (r == o ? 'o' : 'e'), Time.now.to_f, line.inspect
      end
    end
  end

thread.join
end

-a
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