Module: FunkySystem

Defined in:
lib/funkysystem.rb,
lib/funkysystem/version.rb

Defined Under Namespace

Classes: ProgramOutput

Constant Summary collapse

VERSION = 
"0.0.1"

Class Method Summary collapse

Class Method Details

.find_exec(name) ⇒ Object 



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# File 'lib/funkysystem.rb', line 50

def self.find_exec(name)
  ENV["PATH"].split(/:/).each do |bin|
    path = File.join(File.expand_path(bin), name)
    begin
      stat = File.stat(path)
      if stat.executable? && stat.file?
        return path
      end
    rescue Errno::ENOENT
    end
  end
  nil
end

.output_to_writeable_io(out, &block) ⇒ Object 



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# File 'lib/funkysystem.rb', line 24

def self.output_to_writeable_io(out, &block)
  case out
  when String
    File.open(out, 'w', &block)
  when IO
    yield(out)
  #when nil
  else
    File.open('/dev/null', 'w', &block)
  end
end

.redirect_output(options = {}, &block) ⇒ Object

Run block, but with output redirected to elsewhere

Parameters:

  • outputs (Hash) —

    :stdout & :stderr - either an IO object, a filename or nil to redirect stream to /dev/null



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# File 'lib/funkysystem.rb', line 8

def self.redirect_output(options = {}, &block)
  stderr_dup = STDERR.dup
  stdout_dup = STDOUT.dup
  begin
    output_to_writeable_io(options[:stdout]) do |out|
      STDOUT.reopen(out)
      output_to_writeable_io(options[:stderr]) do |err|
        STDERR.reopen(err)
        block.call
      end
    end
  ensure
    STDERR.reopen(stderr_dup)
    STDOUT.reopen(stdout_dup)
  end
end

.run(cmd, stdin = nil) ⇒ Object 



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# File 'lib/funkysystem.rb', line 63

def self.run(cmd, stdin=nil)
  fps = {
    :stdout => IO.pipe,
    :stderr => IO.pipe
  }
  
  fps[:stdin] = IO.pipe if stdin
  
  fps.each do |key,fpa|
    class << fpa
      alias :reader :first
      alias :writer :last
    end
  end
  
  pid = fork do
    keep = [STDERR, STDOUT, STDIN] + fps.values.flatten
    ObjectSpace.each_object(IO) { |io|
      begin
        io.close() unless keep.include?(io)
      rescue Exception
      end
    }
    if fps[:stdin]
      fps[:stdin].writer.close
      STDIN.reopen(fps[:stdin].reader)
      fps[:stdin].reader.close
    else
      # No input - child shouldn't
      # be allowed to expect any...
      STDIN.close()
    end
    
    fps[:stdout].reader.close
    STDOUT.reopen(fps[:stdout].writer)
    fps[:stdout].writer.close
    
    fps[:stderr].reader.close
    STDERR.reopen(fps[:stderr].writer)
    fps[:stderr].writer.close
    
    exec(* ( cmd.is_a?(Array) ? cmd : [cmd] ) )
  end
  
  fps[:stderr].writer.close
  fps[:stdout].writer.close
  
  if fps[:stdin]
    fps[:stdin].reader.close 
    out_fds = [fps[:stdin].writer]
  else
    out_fds = []
  end
  
  in_fds  = [fps[:stderr].reader, fps[:stdout].reader]
  all_fds = in_fds + out_fds
  
  all_fds.each { |fd| fd.nonblock = true }
  
  stdout = ''
  stderr = ''
  exited = nil
  exit_time = nil
  
  until exited && (in_fds.all? { |fd| fd.closed? or fd.eof? } || exit_time < (Time.now.to_i - 3) )
    exited ||= Process.waitpid2(pid, Process::WNOHANG)
    exit_time ||= Time.now.to_i if exited
    begin
      rd, wr, er = select(in_fds, out_fds, all_fds, 0.05)
    rescue IOError
      [in_fds, out_fds, all_fds].each { |grp|
        grp.reject!{ |fd| fd.closed? }
      }
      rd = wr = er = nil
    end
    wr.each do |fd|
      begin
        case fd
        when fps[:stdin].writer
          size = fd.syswrite(stdin)
          stdin = stdin[size..-1]
          if stdin.empty?
            fd.close
            out_fds = []
            stdin = nil
          end
        end
      rescue Errno::EPIPE, IOError
      end
    end if wr.respond_to?(:each)
          
    rd.each do |fd|
      begin
        case fd
        when fps[:stderr].reader
          stderr << fd.sysread(4096 * 4)
        when fps[:stdout].reader
          stdout << fd.sysread(4096 * 4)
        end
      rescue Errno::EPIPE, IOError
      end
    end if rd.respond_to?(:each)

  end
  
  ProgramOutput.new(pid, exited.last, stdout, stderr, stdin)
end