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
   8 #include <string>
   9
  10 #include "base/base_export.h"
  11 #include "build/build_config.h"
  12
  13 namespace base {
  14
  15 namespace env_vars {
  16
  17 #if defined(OS_POSIX)
  18 BASE_EXPORT extern const char kHome[];
  19 #endif
  20
  21 }  // namespace env_vars
  22
  23 class BASE_EXPORT Environment {
  24  public:
  25   virtual ~Environment();
  26
  27   // Static factory method that returns the implementation that provide the
  28   // appropriate platform-specific instance.
  29   static Environment* Create();
  30
  31   // Gets an environment variable's value and stores it in |result|.
  32   // Returns false if the key is unset.
  33   virtual bool GetVar(const char* variable_name, std::string* result) = 0;
  34
  35   // Syntactic sugar for GetVar(variable_name, NULL);
  36   virtual bool HasVar(const char* variable_name);
  37
  38   // Returns true on success, otherwise returns false.
  39   virtual bool SetVar(const char* variable_name,
  40                       const std::string& new_value) = 0;
  41
  42   // Returns true on success, otherwise returns false.
  43   virtual bool UnSetVar(const char* variable_name) = 0;
  44 };
  45
  46 }  // namespace base
  47
  48 #endif  // BASE_ENVIRONMENT_H_