Module Open3
In: lib/open3.rb

open3.rb: Spawn a program like popen, but with stderr, too. You might also want to use this if you want to bypass the shell. (By passing multiple args, which IO#popen does not allow)

Usage: 

  require "open3"

  stdin, stdout, stderr = Open3.popen3('nroff -man')

or: 

  include Open3

  stdin, stdout, stderr = popen3('nroff -man')

popen3 can also take a block which will receive stdin, stdout and stderr as parameters. This ensures stdin, stdout and stderr are closed once the block exits.

Such as: 

  Open3.popen3('nroff -man') { |stdin, stdout, stderr| ... }

Methods

popen3  

Public Instance methods

popen3(*cmd) {|| ...}
stdin, stdout, stderr
= popen3(command);

[Source]

    # File lib/open3.rb, line 27
27:   def popen3(*cmd)
28:     pw = IO::pipe   # pipe[0] for read, pipe[1] for write
29:     pr = IO::pipe
30:     pe = IO::pipe
31: 
32:     pid = fork{
33:       # child
34:       fork{
35:         # grandchild
36:         pw[1].close
37:         STDIN.reopen(pw[0])
38:         pw[0].close
39: 
40:         pr[0].close
41:         STDOUT.reopen(pr[1])
42:         pr[1].close
43: 
44:         pe[0].close
45:         STDERR.reopen(pe[1])
46:         pe[1].close
47: 
48:         exec(*cmd)
49:       }
50:       exit!(0)
51:     }
52: 
53:     pw[0].close
54:     pr[1].close
55:     pe[1].close
56:     Process.waitpid(pid)
57:     pi = [pw[1], pr[0], pe[0]]
58:     pw[1].sync = true
59:     if defined? yield
60:       begin
61:         return yield(*pi)
62:       ensure
63:         pi.each{|p| p.close unless p.closed?}
64:       end
65:     end
66:     pi
67:   end

[Validate]