// Copyright (c) 2012 The Chromium Authors. All rights reserved. // 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 "base/memory/ptr_util.h" #include "base/strings/string_piece.h" #include "base/strings/string_util.h" #include "base/strings/utf_string_conversions.h" #include "build/build_config.h" #if BUILDFLAG(IS_WIN) #include #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) #include #endif namespace base { namespace { class EnvironmentImpl : public Environment { public: bool GetVar(StringPiece 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(StringPiece variable_name, const std::string& new_value) override { return SetVarImpl(variable_name, new_value); } bool UnSetVar(StringPiece variable_name) override { return UnSetVarImpl(variable_name); } private: bool GetVarImpl(StringPiece variable_name, std::string* result) { #if BUILDFLAG(IS_WIN) DWORD value_length = ::GetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), nullptr, 0); if (value_length == 0) return false; if (result) { std::unique_ptr value(new wchar_t[value_length]); ::GetEnvironmentVariable(UTF8ToWide(variable_name).c_str(), value.get(), value_length); *result = WideToUTF8(value.get()); } return true; #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) const char* env_value = getenv(variable_name.data()); if (!env_value) return false; // Note that the variable may be defined but empty. if (result) *result = env_value; return true; #endif } bool SetVarImpl(StringPiece 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(StringPiece 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::Create() { return std::make_unique(); } bool Environment::HasVar(StringPiece variable_name) { return GetVar(variable_name, nullptr); } } // namespace base