From: Pit Capitain <pit@...>
Date: 2006-10-05T16:14:29+09:00
Subject: Re: command help

Tom Allison schrieb:
>>> hostname = open("|hostname").gets
 >
> What's with the pipe being at the wrong end?
> What's the thinking behind that?

You can find a short description in ri or the Pickaxe:

C:\tmp>ri IO
-------------------------------------------------------------- Class: IO
      Class +IO+ is the basis for all input and output in Ruby. An I/O
      stream may be _duplexed_ (that is, bidirectional), and so may use
      more than one native operating system stream.

      Many of the examples in this section use class +File+, the only
      standard subclass of +IO+. The two classes are closely associated.

      As used in this section, _portname_ may take any of the following
      forms.

      *   A plain string represents a filename suitable for the
          underlying operating system.

 >>>>>
      *   A string starting with ``+|+'' indicates a subprocess. The
          remainder of the string following the ``+|+'' is invoked as a
          process with appropriate input/output channels connected to it.
 >>>>>

      *   A string equal to ``+|-+'' will create another Ruby instance as
          a subprocess.

Regards,
Pit