Add back my original example of Shellwords#shellescape.

* lib/shellwords.rb (Shellwords#shellescape): Add back my original
  real world example with some enhancement.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37577 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,6 +1,9 @@
-Fri Nov  9 15:13:16 2012  Akinori MUSHA  <[email protected]>
+Fri Nov  9 15:25:42 2012  Akinori MUSHA  <[email protected]>
 
-	* lib/shellwords.rb (Shellwords#shellescape): Undo part of the
+	* lib/shellwords.rb (Shellwords#shellescape): Add back my original
+	  real world example with some enhancement.
+
+	* lib/shellwords.rb (Shellwords#shelljoin): Undo part of the
 	  previous rdoc change.  This new example using a string-only
 	  array was not in line with the description.
 

lib/shellwords.rb

@@ -105,6 +105,15 @@ class << self
   #   argv = "It's better to give than to receive".shellescape
   #   argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive"
   #
+  #   # Search files in lib for method definitions
+  #   pattern = "^[ \t]*def "
+  #   open("| grep -Ern #{pattern.shellescape} lib") { |grep|
+  #     grep.each_line { |line|
+  #       file, lineno, matched_line = line.split(':', 3)
+  #       # ...
+  #     }
+  #   }
+  #
   # It is the caller's responsibility to encode the string in the right
   # encoding for the shell environment where this string is used.
   #