base/environment.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_ENVIRONMENT_H_
   6 #define BASE_ENVIRONMENT_H_
   7 #pragma once
   8
   9 #include <string>
  10
  11 #include "base/base_export.h"
  12 #include "build/build_config.h"
  13
  14 namespace base {
  15
  16 namespace env_vars {
  17
  18 #if defined(OS_POSIX)
  19 BASE_EXPORT extern const char kHome[];
  20 #endif
  21
  22 }  // namespace env_vars
  23
  24 class BASE_EXPORT Environment {
  25  public:
  26   virtual ~Environment();
  27
  28   // Static factory method that returns the implementation that provide the
  29   // appropriate platform-specific instance.
  30   static Environment* Create();
  31
  32   // Gets an environment variable's value and stores it in |result|.
  33   // Returns false if the key is unset.
  34   virtual bool GetVar(const char* variable_name, std::string* result) = 0;
  35
  36   // Syntactic sugar for GetVar(variable_name, NULL);
  37   virtual bool HasVar(const char* variable_name);
  38
  39   // Returns true on success, otherwise returns false.
  40   virtual bool SetVar(const char* variable_name,
  41                       const std::string& new_value) = 0;
  42
  43   // Returns true on success, otherwise returns false.
  44   virtual bool UnSetVar(const char* variable_name) = 0;
  45 };
  46
  47 }  // namespace base
  48
  49 #endif  // BASE_ENVIRONMENT_H_