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
  31 // Since we use a lazy match, make sure that longer versions (like "--") are
  32 // listed before shorter versions (like "-") of similar prefixes.
  33 #if defined(OS_WIN)
  34 // By putting slash last, we can control whether it is treaded as a switch
  35 // value by changing the value of switch_prefix_count to be one less than
  36 // the array size.
  37 const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
  38 #elif defined(OS_POSIX)
  39 // Unixes don't use slash as a switch.
  40 const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
  41 #endif
  42 size_t switch_prefix_count = arraysize(kSwitchPrefixes);
  43
  44 size_t GetSwitchPrefixLength(const CommandLine::StringType& string) {
  45   for (size_t i = 0; i < switch_prefix_count; ++i) {
  46     CommandLine::StringType prefix(kSwitchPrefixes[i]);
  47     if (string.compare(0, prefix.length(), prefix) == 0)
  48       return prefix.length();
  49   }
  50   return 0;
  51 }
  52
  53 // Fills in |switch_string| and |switch_value| if |string| is a switch.
  54 // This will preserve the input switch prefix in the output |switch_string|.
  55 bool IsSwitch(const CommandLine::StringType& string,
  56               CommandLine::StringType* switch_string,
  57               CommandLine::StringType* switch_value) {
  58   switch_string->clear();
  59   switch_value->clear();
  60   size_t prefix_length = GetSwitchPrefixLength(string);
  61   if (prefix_length == 0 || prefix_length == string.length())
  62     return false;
  63
  64   const size_t equals_position = string.find(kSwitchValueSeparator);
  65   *switch_string = string.substr(0, equals_position);
  66   if (equals_position != CommandLine::StringType::npos)
  67     *switch_value = string.substr(equals_position + 1);
  68   return true;
  69 }
  70
  71 // Append switches and arguments, keeping switches before arguments.
  72 void AppendSwitchesAndArguments(CommandLine& command_line,
  73                                 const CommandLine::StringVector& argv) {
  74   bool parse_switches = true;
  75   for (size_t i = 1; i < argv.size(); ++i) {
  76     CommandLine::StringType arg = argv[i];
  77     TrimWhitespace(arg, TRIM_ALL, &arg);
  78
  79     CommandLine::StringType switch_string;
  80     CommandLine::StringType switch_value;
  81     parse_switches &= (arg != kSwitchTerminator);
  82     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
  83 #if defined(OS_WIN)
  84       command_line.AppendSwitchNative(WideToASCII(switch_string), switch_value);
  85 #elif defined(OS_POSIX)
  86       command_line.AppendSwitchNative(switch_string, switch_value);
  87 #endif
  88     } else {
  89       command_line.AppendArgNative(arg);
  90     }
  91   }
  92 }
  93
  94 // Lowercase switches for backwards compatiblity *on Windows*.
  95 std::string LowerASCIIOnWindows(const std::string& string) {
  96 #if defined(OS_WIN)
  97   return StringToLowerASCII(string);
  98 #elif defined(OS_POSIX)
  99   return string;
 100 #endif
 101 }
 102
 103
 104 #if defined(OS_WIN)
 105 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
 106 std::wstring QuoteForCommandLineToArgvW(const std::wstring& arg) {
 107   // We follow the quoting rules of CommandLineToArgvW.
 108   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 109   if (arg.find_first_of(L" \\\"") == std::wstring::npos) {
 110     // No quoting necessary.
 111     return arg;
 112   }
 113
 114   std::wstring out;
 115   out.push_back(L'"');
 116   for (size_t i = 0; i < arg.size(); ++i) {
 117     if (arg[i] == '\\') {
 118       // Find the extent of this run of backslashes.
 119       size_t start = i, end = start + 1;
 120       for (; end < arg.size() && arg[end] == '\\'; ++end)
 121         /* empty */;
 122       size_t backslash_count = end - start;
 123
 124       // Backslashes are escapes only if the run is followed by a double quote.
 125       // Since we also will end the string with a double quote, we escape for
 126       // either a double quote or the end of the string.
 127       if (end == arg.size() || arg[end] == '"') {
 128         // To quote, we need to output 2x as many backslashes.
 129         backslash_count *= 2;
 130       }
 131       for (size_t j = 0; j < backslash_count; ++j)
 132         out.push_back('\\');
 133
 134       // Advance i to one before the end to balance i++ in loop.
 135       i = end - 1;
 136     } else if (arg[i] == '"') {
 137       out.push_back('\\');
 138       out.push_back('"');
 139     } else {
 140       out.push_back(arg[i]);
 141     }
 142   }
 143   out.push_back('"');
 144
 145   return out;
 146 }
 147 #endif
 148
 149 }  // namespace
 150
 151 CommandLine::CommandLine(NoProgram no_program)
 152     : argv_(1),
 153       begin_args_(1) {
 154 }
 155
 156 CommandLine::CommandLine(const FilePath& program)
 157     : argv_(1),
 158       begin_args_(1) {
 159   SetProgram(program);
 160 }
 161
 162 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 163     : argv_(1),
 164       begin_args_(1) {
 165   InitFromArgv(argc, argv);
 166 }
 167
 168 CommandLine::CommandLine(const StringVector& argv)
 169     : argv_(1),
 170       begin_args_(1) {
 171   InitFromArgv(argv);
 172 }
 173
 174 CommandLine::~CommandLine() {
 175 }
 176
 177 #if defined(OS_WIN)
 178 // static
 179 void CommandLine::set_slash_is_not_a_switch() {
 180   // The last switch prefix should be slash, so adjust the size to skip it.
 181   DCHECK(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/") == 0);
 182   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
 183 }
 184 #endif
 185
 186 // static
 187 bool CommandLine::Init(int argc, const char* const* argv) {
 188   if (current_process_commandline_) {
 189     // If this is intentional, Reset() must be called first. If we are using
 190     // the shared build mode, we have to share a single object across multiple
 191     // shared libraries.
 192     return false;
 193   }
 194
 195   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 196 #if defined(OS_WIN)
 197   current_process_commandline_->ParseFromString(::GetCommandLineW());
 198 #elif defined(OS_POSIX)
 199   current_process_commandline_->InitFromArgv(argc, argv);
 200 #endif
 201
 202   return true;
 203 }
 204
 205 // static
 206 void CommandLine::Reset() {
 207   DCHECK(current_process_commandline_);
 208   delete current_process_commandline_;
 209   current_process_commandline_ = NULL;
 210 }
 211
 212 // static
 213 CommandLine* CommandLine::ForCurrentProcess() {
 214   DCHECK(current_process_commandline_);
 215   return current_process_commandline_;
 216 }
 217
 218 // static
 219 bool CommandLine::InitializedForCurrentProcess() {
 220   return !!current_process_commandline_;
 221 }
 222
 223 #if defined(OS_WIN)
 224 // static
 225 CommandLine CommandLine::FromString(const std::wstring& command_line) {
 226   CommandLine cmd(NO_PROGRAM);
 227   cmd.ParseFromString(command_line);
 228   return cmd;
 229 }
 230 #endif
 231
 232 void CommandLine::InitFromArgv(int argc,
 233                                const CommandLine::CharType* const* argv) {
 234   StringVector new_argv;
 235   for (int i = 0; i < argc; ++i)
 236     new_argv.push_back(argv[i]);
 237   InitFromArgv(new_argv);
 238 }
 239
 240 void CommandLine::InitFromArgv(const StringVector& argv) {
 241   argv_ = StringVector(1);
 242   switches_.clear();
 243   begin_args_ = 1;
 244   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 245   AppendSwitchesAndArguments(*this, argv);
 246 }
 247
 248 CommandLine::StringType CommandLine::GetCommandLineString() const {
 249   StringType string(argv_[0]);
 250 #if defined(OS_WIN)
 251   string = QuoteForCommandLineToArgvW(string);
 252 #endif
 253   StringType params(GetArgumentsString());
 254   if (!params.empty()) {
 255     string.append(StringType(FILE_PATH_LITERAL(" ")));
 256     string.append(params);
 257   }
 258   return string;
 259 }
 260
 261 CommandLine::StringType CommandLine::GetArgumentsString() const {
 262   StringType params;
 263   // Append switches and arguments.
 264   bool parse_switches = true;
 265   for (size_t i = 1; i < argv_.size(); ++i) {
 266     StringType arg = argv_[i];
 267     StringType switch_string;
 268     StringType switch_value;
 269     parse_switches &= arg != kSwitchTerminator;
 270     if (i > 1)
 271       params.append(StringType(FILE_PATH_LITERAL(" ")));
 272     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 273       params.append(switch_string);
 274       if (!switch_value.empty()) {
 275 #if defined(OS_WIN)
 276         switch_value = QuoteForCommandLineToArgvW(switch_value);
 277 #endif
 278         params.append(kSwitchValueSeparator + switch_value);
 279       }
 280     }
 281     else {
 282 #if defined(OS_WIN)
 283       arg = QuoteForCommandLineToArgvW(arg);
 284 #endif
 285       params.append(arg);
 286     }
 287   }
 288   return params;
 289 }
 290
 291 FilePath CommandLine::GetProgram() const {
 292   return FilePath(argv_[0]);
 293 }
 294
 295 void CommandLine::SetProgram(const FilePath& program) {
 296   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 297 }
 298
 299 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 300   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 301 }
 302
 303 std::string CommandLine::GetSwitchValueASCII(
 304     const std::string& switch_string) const {
 305   StringType value = GetSwitchValueNative(switch_string);
 306   if (!IsStringASCII(value)) {
 307     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 308     return std::string();
 309   }
 310 #if defined(OS_WIN)
 311   return WideToASCII(value);
 312 #else
 313   return value;
 314 #endif
 315 }
 316
 317 FilePath CommandLine::GetSwitchValuePath(
 318     const std::string& switch_string) const {
 319   return FilePath(GetSwitchValueNative(switch_string));
 320 }
 321
 322 CommandLine::StringType CommandLine::GetSwitchValueNative(
 323     const std::string& switch_string) const {
 324   SwitchMap::const_iterator result =
 325     switches_.find(LowerASCIIOnWindows(switch_string));
 326   return result == switches_.end() ? StringType() : result->second;
 327 }
 328
 329 void CommandLine::AppendSwitch(const std::string& switch_string) {
 330   AppendSwitchNative(switch_string, StringType());
 331 }
 332
 333 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 334                                    const FilePath& path) {
 335   AppendSwitchNative(switch_string, path.value());
 336 }
 337
 338 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 339                                      const CommandLine::StringType& value) {
 340   std::string switch_key(LowerASCIIOnWindows(switch_string));
 341 #if defined(OS_WIN)
 342   StringType combined_switch_string(base::ASCIIToWide(switch_key));
 343 #elif defined(OS_POSIX)
 344   StringType combined_switch_string(switch_string);
 345 #endif
 346   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 347   switches_[switch_key.substr(prefix_length)] = value;
 348   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 349   if (prefix_length == 0)
 350     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 351   if (!value.empty())
 352     combined_switch_string += kSwitchValueSeparator + value;
 353   // Append the switch and update the switches/arguments divider |begin_args_|.
 354   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 355 }
 356
 357 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 358                                     const std::string& value_string) {
 359 #if defined(OS_WIN)
 360   AppendSwitchNative(switch_string, base::ASCIIToWide(value_string));
 361 #elif defined(OS_POSIX)
 362   AppendSwitchNative(switch_string, value_string);
 363 #endif
 364 }
 365
 366 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 367                                    const char* const switches[],
 368                                    size_t count) {
 369   for (size_t i = 0; i < count; ++i) {
 370     if (source.HasSwitch(switches[i]))
 371       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 372   }
 373 }
 374
 375 CommandLine::StringVector CommandLine::GetArgs() const {
 376   // Gather all arguments after the last switch (may include kSwitchTerminator).
 377   StringVector args(argv_.begin() + begin_args_, argv_.end());
 378   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 379   StringVector::iterator switch_terminator =
 380       std::find(args.begin(), args.end(), kSwitchTerminator);
 381   if (switch_terminator != args.end())
 382     args.erase(switch_terminator);
 383   return args;
 384 }
 385
 386 void CommandLine::AppendArg(const std::string& value) {
 387 #if defined(OS_WIN)
 388   DCHECK(IsStringUTF8(value));
 389   AppendArgNative(base::UTF8ToWide(value));
 390 #elif defined(OS_POSIX)
 391   AppendArgNative(value);
 392 #endif
 393 }
 394
 395 void CommandLine::AppendArgPath(const FilePath& path) {
 396   AppendArgNative(path.value());
 397 }
 398
 399 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 400   argv_.push_back(value);
 401 }
 402
 403 void CommandLine::AppendArguments(const CommandLine& other,
 404                                   bool include_program) {
 405   if (include_program)
 406     SetProgram(other.GetProgram());
 407   AppendSwitchesAndArguments(*this, other.argv());
 408 }
 409
 410 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 411   if (wrapper.empty())
 412     return;
 413   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 414   // we don't pretend to do anything fancy, we just split on spaces.
 415   StringVector wrapper_argv;
 416   base::SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 417   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 418   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 419   begin_args_ += wrapper_argv.size();
 420 }
 421
 422 #if defined(OS_WIN)
 423 void CommandLine::ParseFromString(const std::wstring& command_line) {
 424   std::wstring command_line_string;
 425   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 426   if (command_line_string.empty())
 427     return;
 428
 429   int num_args = 0;
 430   wchar_t** args = NULL;
 431   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 432
 433   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 434                          << command_line;
 435   InitFromArgv(num_args, args);
 436   LocalFree(args);
 437 }
 438 #endif