| // Copyright 2012 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/environment.h" |
| |
| #include <array> |
| #include <string_view> |
| |
| #include "base/memory/ptr_util.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/utf_string_conversions.h" |
| #include "build/build_config.h" |
| |
| #if BUILDFLAG(IS_WIN) |
| #include <windows.h> |
| #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| #include <stdlib.h> |
| #endif |
| |
| namespace base { |
| |
| namespace { |
| |
| class EnvironmentImpl : public Environment { |
| public: |
| bool GetVar(std::string_view variable_name, std::string* result) override { |
| if (GetVarImpl(variable_name, result)) |
| return true; |
| |
| // Some commonly used variable names are uppercase while others |
| // are lowercase, which is inconsistent. Let's try to be helpful |
| // and look for a variable name with the reverse case. |
| // I.e. HTTP_PROXY may be http_proxy for some users/systems. |
| char first_char = variable_name[0]; |
| std::string alternate_case_var; |
| if (IsAsciiLower(first_char)) |
| alternate_case_var = ToUpperASCII(variable_name); |
| else if (IsAsciiUpper(first_char)) |
| alternate_case_var = ToLowerASCII(variable_name); |
| else |
| return false; |
| return GetVarImpl(alternate_case_var, result); |
| } |
| |
| bool SetVar(std::string_view variable_name, |
| const std::string& new_value) override { |
| return SetVarImpl(variable_name, new_value); |
| } |
| |
| bool UnSetVar(std::string_view variable_name) override { |
| return UnSetVarImpl(variable_name); |
| } |
| |
| private: |
| bool GetVarImpl(std::string_view variable_name, std::string* result) { |
| #if BUILDFLAG(IS_WIN) |
| std::wstring wide_name = UTF8ToWide(variable_name); |
| if (!result) { |
| return ::GetEnvironmentVariable(wide_name.c_str(), nullptr, 0) != 0; |
| } |
| // Documented to be the maximum environment variable size. |
| std::array<wchar_t, 32767> value; |
| DWORD value_length = |
| ::GetEnvironmentVariable(wide_name.c_str(), value.data(), value.size()); |
| if (value_length == 0) { |
| return false; |
| } |
| CHECK_LE(value_length, value.size() - 1) |
| << "value should fit in the buffer (including the null terminator)"; |
| WideToUTF8(value.data(), value_length, result); |
| return true; |
| #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| const char* env_value = getenv(std::string(variable_name).c_str()); |
| if (!env_value) |
| return false; |
| // Note that the variable may be defined but empty. |
| if (result) |
| *result = env_value; |
| return true; |
| #endif |
| } |
| |
| bool SetVarImpl(std::string_view variable_name, |
| const std::string& new_value) { |
| #if BUILDFLAG(IS_WIN) |
| // On success, a nonzero value is returned. |
| return !!SetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), |
| UTF8ToWide(new_value).c_str()); |
| #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| // On success, zero is returned. |
| return !setenv(variable_name.data(), new_value.c_str(), 1); |
| #endif |
| } |
| |
| bool UnSetVarImpl(std::string_view variable_name) { |
| #if BUILDFLAG(IS_WIN) |
| // On success, a nonzero value is returned. |
| return !!SetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), nullptr); |
| #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| // On success, zero is returned. |
| return !unsetenv(variable_name.data()); |
| #endif |
| } |
| }; |
| |
| } // namespace |
| |
| namespace env_vars { |
| |
| #if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| // On Posix systems, this variable contains the location of the user's home |
| // directory. (e.g, /home/username/). |
| const char kHome[] = "HOME"; |
| #endif |
| |
| } // namespace env_vars |
| |
| Environment::~Environment() = default; |
| |
| // static |
| std::unique_ptr<Environment> Environment::Create() { |
| return std::make_unique<EnvironmentImpl>(); |
| } |
| |
| bool Environment::HasVar(std::string_view variable_name) { |
| return GetVar(variable_name, nullptr); |
| } |
| |
| } // namespace base |