base/command_line.cc

   1 // Copyright (c) 2012 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/command_line.h"
   6
   7 #include <algorithm>
   8 #include <ostream>
   9
  10 #include "base/basictypes.h"
  11 #include "base/files/file_path.h"
  12 #include "base/logging.h"
  13 #include "base/strings/string_split.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/strings/utf_string_conversions.h"
  16 #include "build/build_config.h"
  17
  18 #if defined(OS_WIN)
  19 #include <windows.h>
  20 #include <shellapi.h>
  21 #endif
  22
  23 using base::FilePath;
  24
  25 CommandLine* CommandLine::current_process_commandline_ = NULL;
  26
  27 namespace {
  28 const CommandLine::CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
  29 const CommandLine::CharType kSwitchValueSeparator[] = FILE_PATH_LITERAL("=");
  30 // Since we use a lazy match, make sure that longer versions (like "--") are
  31 // listed before shorter versions (like "-") of similar prefixes.
  32 #if defined(OS_WIN)
  33 const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
  34 #elif defined(OS_POSIX)
  35 // Unixes don't use slash as a switch.
  36 const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
  37 #endif
  38
  39 size_t GetSwitchPrefixLength(const CommandLine::StringType& string) {
  40   for (size_t i = 0; i < arraysize(kSwitchPrefixes); ++i) {
  41     CommandLine::StringType prefix(kSwitchPrefixes[i]);
  42     if (string.compare(0, prefix.length(), prefix) == 0)
  43       return prefix.length();
  44   }
  45   return 0;
  46 }
  47
  48 // Fills in |switch_string| and |switch_value| if |string| is a switch.
  49 // This will preserve the input switch prefix in the output |switch_string|.
  50 bool IsSwitch(const CommandLine::StringType& string,
  51               CommandLine::StringType* switch_string,
  52               CommandLine::StringType* switch_value) {
  53   switch_string->clear();
  54   switch_value->clear();
  55   size_t prefix_length = GetSwitchPrefixLength(string);
  56   if (prefix_length == 0 || prefix_length == string.length())
  57     return false;
  58
  59   const size_t equals_position = string.find(kSwitchValueSeparator);
  60   *switch_string = string.substr(0, equals_position);
  61   if (equals_position != CommandLine::StringType::npos)
  62     *switch_value = string.substr(equals_position + 1);
  63   return true;
  64 }
  65
  66 // Append switches and arguments, keeping switches before arguments.
  67 void AppendSwitchesAndArguments(CommandLine& command_line,
  68                                 const CommandLine::StringVector& argv) {
  69   bool parse_switches = true;
  70   for (size_t i = 1; i < argv.size(); ++i) {
  71     CommandLine::StringType arg = argv[i];
  72     TrimWhitespace(arg, TRIM_ALL, &arg);
  73
  74     CommandLine::StringType switch_string;
  75     CommandLine::StringType switch_value;
  76     parse_switches &= (arg != kSwitchTerminator);
  77     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
  78 #if defined(OS_WIN)
  79       command_line.AppendSwitchNative(WideToASCII(switch_string), switch_value);
  80 #elif defined(OS_POSIX)
  81       command_line.AppendSwitchNative(switch_string, switch_value);
  82 #endif
  83     } else {
  84       command_line.AppendArgNative(arg);
  85     }
  86   }
  87 }
  88
  89 // Lowercase switches for backwards compatiblity *on Windows*.
  90 std::string LowerASCIIOnWindows(const std::string& string) {
  91 #if defined(OS_WIN)
  92   return StringToLowerASCII(string);
  93 #elif defined(OS_POSIX)
  94   return string;
  95 #endif
  96 }
  97
  98
  99 #if defined(OS_WIN)
 100 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
 101 std::wstring QuoteForCommandLineToArgvW(const std::wstring& arg) {
 102   // We follow the quoting rules of CommandLineToArgvW.
 103   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 104   if (arg.find_first_of(L" \\\"") == std::wstring::npos) {
 105     // No quoting necessary.
 106     return arg;
 107   }
 108
 109   std::wstring out;
 110   out.push_back(L'"');
 111   for (size_t i = 0; i < arg.size(); ++i) {
 112     if (arg[i] == '\\') {
 113       // Find the extent of this run of backslashes.
 114       size_t start = i, end = start + 1;
 115       for (; end < arg.size() && arg[end] == '\\'; ++end)
 116         /* empty */;
 117       size_t backslash_count = end - start;
 118
 119       // Backslashes are escapes only if the run is followed by a double quote.
 120       // Since we also will end the string with a double quote, we escape for
 121       // either a double quote or the end of the string.
 122       if (end == arg.size() || arg[end] == '"') {
 123         // To quote, we need to output 2x as many backslashes.
 124         backslash_count *= 2;
 125       }
 126       for (size_t j = 0; j < backslash_count; ++j)
 127         out.push_back('\\');
 128
 129       // Advance i to one before the end to balance i++ in loop.
 130       i = end - 1;
 131     } else if (arg[i] == '"') {
 132       out.push_back('\\');
 133       out.push_back('"');
 134     } else {
 135       out.push_back(arg[i]);
 136     }
 137   }
 138   out.push_back('"');
 139
 140   return out;
 141 }
 142 #endif
 143
 144 }  // namespace
 145
 146 CommandLine::CommandLine(NoProgram no_program)
 147     : argv_(1),
 148       begin_args_(1) {
 149 }
 150
 151 CommandLine::CommandLine(const FilePath& program)
 152     : argv_(1),
 153       begin_args_(1) {
 154   SetProgram(program);
 155 }
 156
 157 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 158     : argv_(1),
 159       begin_args_(1) {
 160   InitFromArgv(argc, argv);
 161 }
 162
 163 CommandLine::CommandLine(const StringVector& argv)
 164     : argv_(1),
 165       begin_args_(1) {
 166   InitFromArgv(argv);
 167 }
 168
 169 CommandLine::~CommandLine() {
 170 }
 171
 172 // static
 173 bool CommandLine::Init(int argc, const char* const* argv) {
 174   if (current_process_commandline_) {
 175     // If this is intentional, Reset() must be called first. If we are using
 176     // the shared build mode, we have to share a single object across multiple
 177     // shared libraries.
 178     return false;
 179   }
 180
 181   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 182 #if defined(OS_WIN)
 183   current_process_commandline_->ParseFromString(::GetCommandLineW());
 184 #elif defined(OS_POSIX)
 185   current_process_commandline_->InitFromArgv(argc, argv);
 186 #endif
 187
 188   return true;
 189 }
 190
 191 // static
 192 void CommandLine::Reset() {
 193   DCHECK(current_process_commandline_);
 194   delete current_process_commandline_;
 195   current_process_commandline_ = NULL;
 196 }
 197
 198 // static
 199 CommandLine* CommandLine::ForCurrentProcess() {
 200   DCHECK(current_process_commandline_);
 201   return current_process_commandline_;
 202 }
 203
 204 #if defined(OS_WIN)
 205 // static
 206 CommandLine CommandLine::FromString(const std::wstring& command_line) {
 207   CommandLine cmd(NO_PROGRAM);
 208   cmd.ParseFromString(command_line);
 209   return cmd;
 210 }
 211 #endif
 212
 213 void CommandLine::InitFromArgv(int argc,
 214                                const CommandLine::CharType* const* argv) {
 215   StringVector new_argv;
 216   for (int i = 0; i < argc; ++i)
 217     new_argv.push_back(argv[i]);
 218   InitFromArgv(new_argv);
 219 }
 220
 221 void CommandLine::InitFromArgv(const StringVector& argv) {
 222   argv_ = StringVector(1);
 223   switches_.clear();
 224   begin_args_ = 1;
 225   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 226   AppendSwitchesAndArguments(*this, argv);
 227 }
 228
 229 CommandLine::StringType CommandLine::GetCommandLineString() const {
 230   StringType string(argv_[0]);
 231 #if defined(OS_WIN)
 232   string = QuoteForCommandLineToArgvW(string);
 233 #endif
 234   StringType params(GetArgumentsString());
 235   if (!params.empty()) {
 236     string.append(StringType(FILE_PATH_LITERAL(" ")));
 237     string.append(params);
 238   }
 239   return string;
 240 }
 241
 242 CommandLine::StringType CommandLine::GetArgumentsString() const {
 243   StringType params;
 244   // Append switches and arguments.
 245   bool parse_switches = true;
 246   for (size_t i = 1; i < argv_.size(); ++i) {
 247     StringType arg = argv_[i];
 248     StringType switch_string;
 249     StringType switch_value;
 250     parse_switches &= arg != kSwitchTerminator;
 251     if (i > 1)
 252       params.append(StringType(FILE_PATH_LITERAL(" ")));
 253     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 254       params.append(switch_string);
 255       if (!switch_value.empty()) {
 256 #if defined(OS_WIN)
 257         switch_value = QuoteForCommandLineToArgvW(switch_value);
 258 #endif
 259         params.append(kSwitchValueSeparator + switch_value);
 260       }
 261     }
 262     else {
 263 #if defined(OS_WIN)
 264       arg = QuoteForCommandLineToArgvW(arg);
 265 #endif
 266       params.append(arg);
 267     }
 268   }
 269   return params;
 270 }
 271
 272 FilePath CommandLine::GetProgram() const {
 273   return FilePath(argv_[0]);
 274 }
 275
 276 void CommandLine::SetProgram(const FilePath& program) {
 277   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 278 }
 279
 280 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 281   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 282 }
 283
 284 std::string CommandLine::GetSwitchValueASCII(
 285     const std::string& switch_string) const {
 286   StringType value = GetSwitchValueNative(switch_string);
 287   if (!IsStringASCII(value)) {
 288     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 289     return std::string();
 290   }
 291 #if defined(OS_WIN)
 292   return WideToASCII(value);
 293 #else
 294   return value;
 295 #endif
 296 }
 297
 298 FilePath CommandLine::GetSwitchValuePath(
 299     const std::string& switch_string) const {
 300   return FilePath(GetSwitchValueNative(switch_string));
 301 }
 302
 303 CommandLine::StringType CommandLine::GetSwitchValueNative(
 304     const std::string& switch_string) const {
 305   SwitchMap::const_iterator result = switches_.end();
 306   result = switches_.find(LowerASCIIOnWindows(switch_string));
 307   return result == switches_.end() ? StringType() : result->second;
 308 }
 309
 310 void CommandLine::AppendSwitch(const std::string& switch_string) {
 311   AppendSwitchNative(switch_string, StringType());
 312 }
 313
 314 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 315                                    const FilePath& path) {
 316   AppendSwitchNative(switch_string, path.value());
 317 }
 318
 319 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 320                                      const CommandLine::StringType& value) {
 321   std::string switch_key(LowerASCIIOnWindows(switch_string));
 322 #if defined(OS_WIN)
 323   StringType combined_switch_string(ASCIIToWide(switch_key));
 324 #elif defined(OS_POSIX)
 325   StringType combined_switch_string(switch_string);
 326 #endif
 327   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 328   switches_[switch_key.substr(prefix_length)] = value;
 329   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 330   if (prefix_length == 0)
 331     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 332   if (!value.empty())
 333     combined_switch_string += kSwitchValueSeparator + value;
 334   // Append the switch and update the switches/arguments divider |begin_args_|.
 335   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 336 }
 337
 338 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 339                                     const std::string& value_string) {
 340 #if defined(OS_WIN)
 341   AppendSwitchNative(switch_string, ASCIIToWide(value_string));
 342 #elif defined(OS_POSIX)
 343   AppendSwitchNative(switch_string, value_string);
 344 #endif
 345 }
 346
 347 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 348                                    const char* const switches[],
 349                                    size_t count) {
 350   for (size_t i = 0; i < count; ++i) {
 351     if (source.HasSwitch(switches[i]))
 352       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 353   }
 354 }
 355
 356 CommandLine::StringVector CommandLine::GetArgs() const {
 357   // Gather all arguments after the last switch (may include kSwitchTerminator).
 358   StringVector args(argv_.begin() + begin_args_, argv_.end());
 359   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 360   StringVector::iterator switch_terminator =
 361       std::find(args.begin(), args.end(), kSwitchTerminator);
 362   if (switch_terminator != args.end())
 363     args.erase(switch_terminator);
 364   return args;
 365 }
 366
 367 void CommandLine::AppendArg(const std::string& value) {
 368 #if defined(OS_WIN)
 369   DCHECK(IsStringUTF8(value));
 370   AppendArgNative(UTF8ToWide(value));
 371 #elif defined(OS_POSIX)
 372   AppendArgNative(value);
 373 #endif
 374 }
 375
 376 void CommandLine::AppendArgPath(const FilePath& path) {
 377   AppendArgNative(path.value());
 378 }
 379
 380 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 381   argv_.push_back(value);
 382 }
 383
 384 void CommandLine::AppendArguments(const CommandLine& other,
 385                                   bool include_program) {
 386   if (include_program)
 387     SetProgram(other.GetProgram());
 388   AppendSwitchesAndArguments(*this, other.argv());
 389 }
 390
 391 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 392   if (wrapper.empty())
 393     return;
 394   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 395   // we don't pretend to do anything fancy, we just split on spaces.
 396   StringVector wrapper_argv;
 397   base::SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 398   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 399   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 400   begin_args_ += wrapper_argv.size();
 401 }
 402
 403 #if defined(OS_WIN)
 404 void CommandLine::ParseFromString(const std::wstring& command_line) {
 405   std::wstring command_line_string;
 406   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 407   if (command_line_string.empty())
 408     return;
 409
 410   int num_args = 0;
 411   wchar_t** args = NULL;
 412   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 413
 414   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 415                          << command_line;
 416   InitFromArgv(num_args, args);
 417   LocalFree(args);
 418 }
 419 #endif