Method: Open4.popen4

Defined in:
lib/crazy_ivan/vendor/open4-1.0.1/lib/open4.rb

.popen4(*cmd, &b) ⇒ Object 



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# File 'lib/crazy_ivan/vendor/open4-1.0.1/lib/open4.rb', line 13

def popen4(*cmd, &b)
#--{{{
  pw, pr, pe, ps = IO.pipe, IO.pipe, IO.pipe, IO.pipe

  verbose = $VERBOSE
  begin
    $VERBOSE = nil
    ps.first.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
    ps.last.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)

    cid = fork {
      pw.last.close
      STDIN.reopen pw.first
      pw.first.close

      pr.first.close
      STDOUT.reopen pr.last
      pr.last.close

      pe.first.close
      STDERR.reopen pe.last
      pe.last.close

      STDOUT.sync = STDERR.sync = true

      begin
        exec(*cmd)
        raise 'forty-two' 
      rescue Exception => e
        Marshal.dump(e, ps.last)
        ps.last.flush
      end
      ps.last.close unless (ps.last.closed?)
      exit!
    }
  ensure
    $VERBOSE = verbose
  end

  [pw.first, pr.last, pe.last, ps.last].each{|fd| fd.close}

  begin
    e = Marshal.load ps.first
    raise(Exception === e ? e : "unknown failure!")
  rescue EOFError # If we get an EOF error, then the exec was successful
    42
  ensure
    ps.first.close
  end

  pw.last.sync = true

  pi = [pw.last, pr.first, pe.first]

  if b 
    begin
      b[cid, *pi]
      Process.waitpid2(cid).last
    ensure
      pi.each{|fd| fd.close unless fd.closed?}
    end
  else
    [cid, pw.last, pr.first, pe.first]
  end
#--}}}
end