[cr tool] Adding the info command.

tools/cr/cr/commands/info.py

Index: tools/cr/cr/commands/info.py
diff --git a/tools/cr/cr/commands/info.py b/tools/cr/cr/commands/info.py
new file mode 100644
index 0000000000000000000000000000000000000000..12f2f63c4b02a7ec2ca5d48ee5177f5b92be5380
--- /dev/null
+++ b/tools/cr/cr/commands/info.py
@@ -0,0 +1,43 @@
+# Copyright (c) 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""A module for the info implementation of Command."""
+
+import cr
+
+
+class InfoCommand(cr.Command):
+  """The cr info command implementation."""
+
+  def __init__(self):
+    super(InfoCommand, self).__init__()
+    self.help = 'Print information about the cr environment'
+
+  def AddArguments(self, subparsers):
+    parser = super(InfoCommand, self).AddArguments(subparsers)
+    parser.add_argument(
+        '-s', '--short', dest='_short',
+        action='store_true', default=False,
+        help='Short form results, useful for scripting.'
+    )
+    self.ConsumeArgs(parser, 'the environment')
+    return parser
+
+  def EarlyArgProcessing(self, context):
+    if getattr(context.args, '_short', False):
+      self.requires_build_dir = False
+
+  def Run(self, context):
+    if context.remains:
+      for var in context.remains:
+        if getattr(context.args, '_short', False):
+          val = context.Find(var)
+          if val is None:
+            val = ''
+          print val
+        else:
+          print var, '=', context.Find(var)
+    else:
+      cr.base.client.PrintInfo(context)
+