1 files changed, 55 insertions, 0 deletions
diff --git a/lib/open3.rb b/lib/open3.rb
new file mode 100644
index 0000000000..e8ba2783da
--- /dev/null
+++ b/lib/open3.rb
@@ -0,0 +1,55 @@
+# Usage:
+#	require "open3"
+#
+#	in, out, err = Open3.popen3('nroff -man')
+#  or
+#	include Open3
+#	in, out, err = popen3('nroff -man')
+#
+
+module Open3
+  #[stdin, stdout, stderr] = popen3(command);
+  def popen3(cmd)
+    pw = pipe   # pipe[0] for read, pipe[1] for write
+    pr = pipe
+    pe = pipe
+
+    pid = fork
+    if pid == nil then # child
+      pw[1].close
+      STDIN.reopen(pw[0])
+      pw[0].close
+
+      pr[0].close
+      STDOUT.reopen(pr[1])
+      pr[1].close
+
+      pe[0].close
+      STDERR.reopen(pe[1])
+      pe[1].close
+
+      exec(cmd)
+      exit
+    else
+      pw[0].close
+      pr[1].close
+      pe[1].close
+      pi = [ pw[1], pr[0], pe[0] ]
+    end
+  end
+  module_function :popen3
+end
+
+if $0 == __FILE__
+  a = Open3.popen3("nroff -man")
+  Thread.start do
+    while gets
+      a[0].print $_
+    end
+    a[0].close
+  end
+  while a[1].gets
+    print ":", $_
+  end
+end
+