Add configuration discovery helper method

Sensor configuration is passed to the application via the enviroment.
Create a map of environment values for a given sensor.

Change-Id: I8369eda27798fd9472166e898b8d6166c6997392
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/env.cpp b/env.cpp
new file mode 100644
index 0000000..d77200e
--- /dev/null
+++ b/env.cpp
@@ -0,0 +1,40 @@
+/**
+ * Copyright © 2016 IBM Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <string>
+#include <cstdlib>
+#include "sensorset.hpp"
+
+std::string getEnv(
+    const char* prefix, const SensorSet::key_type& sensor)
+{
+    std::string key;
+    std::string value;
+
+    key.assign(prefix);
+    key.append(1, '_');
+    key.append(sensor.first);
+    key.append(sensor.second);
+    auto env = getenv(key.c_str());
+    if (env)
+    {
+        value.assign(env);
+    }
+
+    return value;
+}
+
+// vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4