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#include "base/environment.h" 6 7#if defined(OS_POSIX) 8#include <stdlib.h> 9#elif defined(OS_WIN) 10#include <windows.h> 11#endif 12 13#include "base/string_util.h" 14 15#if defined(OS_WIN) 16#include "base/memory/scoped_ptr.h" 17#include "base/utf_string_conversions.h" 18#endif 19 20namespace { 21 22class EnvironmentImpl : public base::Environment { 23 public: 24 virtual bool GetVar(const char* variable_name, std::string* result) { 25 if (GetVarImpl(variable_name, result)) 26 return true; 27 28 // Some commonly used variable names are uppercase while others 29 // are lowercase, which is inconsistent. Let's try to be helpful 30 // and look for a variable name with the reverse case. 31 // I.e. HTTP_PROXY may be http_proxy for some users/systems. 32 char first_char = variable_name[0]; 33 std::string alternate_case_var; 34 if (first_char >= 'a' && first_char <= 'z') 35 alternate_case_var = StringToUpperASCII(std::string(variable_name)); 36 else if (first_char >= 'A' && first_char <= 'Z') 37 alternate_case_var = StringToLowerASCII(std::string(variable_name)); 38 else 39 return false; 40 return GetVarImpl(alternate_case_var.c_str(), result); 41 } 42 43 virtual bool SetVar(const char* variable_name, const std::string& new_value) { 44 return SetVarImpl(variable_name, new_value); 45 } 46 47 virtual bool UnSetVar(const char* variable_name) { 48 return UnSetVarImpl(variable_name); 49 } 50 51 private: 52 bool GetVarImpl(const char* variable_name, std::string* result) { 53#if defined(OS_POSIX) 54 const char* env_value = getenv(variable_name); 55 if (!env_value) 56 return false; 57 // Note that the variable may be defined but empty. 58 if (result) 59 *result = env_value; 60 return true; 61#elif defined(OS_WIN) 62 DWORD value_length = ::GetEnvironmentVariable( 63 UTF8ToWide(variable_name).c_str(), NULL, 0); 64 if (value_length == 0) 65 return false; 66 if (result) { 67 scoped_array<wchar_t> value(new wchar_t[value_length]); 68 ::GetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), value.get(), 69 value_length); 70 *result = WideToUTF8(value.get()); 71 } 72 return true; 73#else 74#error need to port 75#endif 76 } 77 78 bool SetVarImpl(const char* variable_name, const std::string& new_value) { 79#if defined(OS_POSIX) 80 // On success, zero is returned. 81 return !setenv(variable_name, new_value.c_str(), 1); 82#elif defined(OS_WIN) 83 // On success, a nonzero value is returned. 84 return !!SetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), 85 UTF8ToWide(new_value).c_str()); 86#endif 87 } 88 89 bool UnSetVarImpl(const char* variable_name) { 90#if defined(OS_POSIX) 91 // On success, zero is returned. 92 return !unsetenv(variable_name); 93#elif defined(OS_WIN) 94 // On success, a nonzero value is returned. 95 return !!SetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), NULL); 96#endif 97 } 98}; 99 100} // namespace 101 102namespace base { 103 104namespace env_vars { 105 106#if defined(OS_POSIX) 107// On Posix systems, this variable contains the location of the user's home 108// directory. (e.g, /home/username/). 109const char kHome[] = "HOME"; 110#endif 111 112} // namespace env_vars 113 114Environment::~Environment() {} 115 116// static 117Environment* Environment::Create() { 118 return new EnvironmentImpl(); 119} 120 121bool Environment::HasVar(const char* variable_name) { 122 return GetVar(variable_name, NULL); 123} 124 125} // namespace base 126