| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| #ifndef LIBMINIFI_INCLUDE_UTILS_ENVIRONMENT_H_ |
| #define LIBMINIFI_INCLUDE_UTILS_ENVIRONMENT_H_ |
| |
| #include <utility> |
| #include <functional> |
| #include <string> |
| |
| namespace org { |
| namespace apache { |
| namespace nifi { |
| namespace minifi { |
| namespace utils { |
| |
| /** |
| * A helper class for interacting with the environment in a thread-safe manner. |
| * Note that if environment access occurs outside of this class (in third parties, or because native setenv/unsetenv/getenv |
| * functions are called natively, and not through this class), then this class can't guarantee thread safety. |
| */ |
| class Environment { |
| private: |
| static bool runningAsService_; |
| |
| static void accessEnvironment(const std::function<void(void)>& func); |
| |
| public: |
| /** |
| * Gets an environment variable using the native OS API |
| * @param name the name of the environment variable |
| * @return a pair consisting of a bool indicating whether the environment variable is set |
| * and an std::string containing the value of the environemnt variable |
| */ |
| static std::pair<bool, std::string> getEnvironmentVariable(const char* name); |
| |
| /** |
| * Sets an environment variable using the native OS API |
| * @param name the name of the environment variable |
| * @param value the desired value of the environment variable |
| * @param overwrite if false, will not replace the value of the environment variable if it is already set |
| * @return true on success. If overwrite is false, will also return true if the environment variable was not changed |
| */ |
| static bool setEnvironmentVariable(const char* name, const char* value, bool overwrite = true); |
| |
| /** |
| * Unsets an environment variable using the native OS API |
| * @param name the name of the environment variable |
| * @return true on success (if the environment variable was successfully unset, or if it did not exist in the first place) |
| */ |
| static bool unsetEnvironmentVariable(const char* name); |
| |
| /** |
| * Determines the current working directory |
| * @return current working directory on success, empty string on failure |
| */ |
| static std::string getCurrentWorkingDirectory(); |
| |
| /** |
| * Changes the current working directory |
| * @param directory the directory to change to |
| * @return true on success |
| */ |
| static bool setCurrentWorkingDirectory(const char* directory); |
| |
| /** |
| * Sets whether the current process is running as a service |
| * @param runningAsService true if the current process is running as a service |
| */ |
| static void setRunningAsService(bool runningAsService); |
| |
| /** |
| * Returns the value set by setRunningAsService |
| * @return true if the current process is running as a service |
| */ |
| static bool isRunningAsService(); |
| }; |
| |
| } // namespace utils |
| } // namespace minifi |
| } // namespace nifi |
| } // namespace apache |
| } // namespace org |
| |
| #endif // LIBMINIFI_INCLUDE_UTILS_ENVIRONMENT_H_ |