[cr tool] Adding the main function and remaining pieces.

tools/cr/cr.sh

Index: tools/cr/cr.sh
diff --git a/tools/cr/cr.sh b/tools/cr/cr.sh
new file mode 100644
index 0000000000000000000000000000000000000000..233fe86b227896b72adab8ad95eddaa221f56932
--- /dev/null
+++ b/tools/cr/cr.sh
@@ -0,0 +1,48 @@
+#!/bin/bash
+
+# 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.
+
+# Source this file into your shell to gain the cr function and tab completion
+# for it
+
+# Make sure we're being sourced (possibly by another script). Check for bash
+# since zsh sets $0 when sourcing.
+if [[ -n "$BASH_VERSION" && "${BASH_SOURCE:-$0}" == "$0" ]]; then
+  echo "ERROR: cr.sh must be sourced."
+  exit 1
+fi
+
+
+cr_base_dir=$(dirname $(realpath "${BASH_SOURCE:-$0}"))
+cr_main="${cr_base_dir}/main.py"
+cr_exec="PYTHONDONTWRITEBYTECODE=1 python ${cr_main}"
+
+# The main entry point to the cr tool.
+# Invokes the python script with pyc files turned off.
+function cr() {
+  env $cr_exec "$@"
+}
+
+# Attempts to cd to the root/src of the current client.
+function crcd() {
+  cd $(cr info -s CR_SRC)
+}
+
+# Add to your PS1 to have the current selected output directory in your prompt
+function _cr_ps1() {
+  cr info -s CR_OUT_FULL
+}
+
+# The tab completion handler, delegates into the python script.
+function _cr_complete() {
+  COMPREPLY=()
+  local cur="${COMP_WORDS[COMP_CWORD]}"
+  local main="python -B "${cr_main}")"
+  local completions="$(env COMP_CWORD=${COMP_CWORD} COMP_WORD=${cur} $cr_exec)"
+  COMPREPLY=( $(compgen -W "${completions}" -- ${cur}) )
+}
+
+# Setup the bash auto complete
+complete -F _cr_complete cr