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 namespace base {
  24
  25 CommandLine* CommandLine::current_process_commandline_ = NULL;
  26
  27 namespace {
  28
  29 const CommandLine::CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
  30 const CommandLine::CharType kSwitchValueSeparator[] = FILE_PATH_LITERAL("=");
  31
  32 // Since we use a lazy match, make sure that longer versions (like "--") are
  33 // listed before shorter versions (like "-") of similar prefixes.
  34 #if defined(OS_WIN)
  35 // By putting slash last, we can control whether it is treaded as a switch
  36 // value by changing the value of switch_prefix_count to be one less than
  37 // the array size.
  38 const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
  39 #elif defined(OS_POSIX)
  40 // Unixes don't use slash as a switch.
  41 const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
  42 #endif
  43 size_t switch_prefix_count = arraysize(kSwitchPrefixes);
  44
  45 size_t GetSwitchPrefixLength(const CommandLine::StringType& string) {
  46   for (size_t i = 0; i < switch_prefix_count; ++i) {
  47     CommandLine::StringType prefix(kSwitchPrefixes[i]);
  48     if (string.compare(0, prefix.length(), prefix) == 0)
  49       return prefix.length();
  50   }
  51   return 0;
  52 }
  53
  54 // Fills in |switch_string| and |switch_value| if |string| is a switch.
  55 // This will preserve the input switch prefix in the output |switch_string|.
  56 bool IsSwitch(const CommandLine::StringType& string,
  57               CommandLine::StringType* switch_string,
  58               CommandLine::StringType* switch_value) {
  59   switch_string->clear();
  60   switch_value->clear();
  61   size_t prefix_length = GetSwitchPrefixLength(string);
  62   if (prefix_length == 0 || prefix_length == string.length())
  63     return false;
  64
  65   const size_t equals_position = string.find(kSwitchValueSeparator);
  66   *switch_string = string.substr(0, equals_position);
  67   if (equals_position != CommandLine::StringType::npos)
  68     *switch_value = string.substr(equals_position + 1);
  69   return true;
  70 }
  71
  72 // Append switches and arguments, keeping switches before arguments.
  73 void AppendSwitchesAndArguments(CommandLine& command_line,
  74                                 const CommandLine::StringVector& argv) {
  75   bool parse_switches = true;
  76   for (size_t i = 1; i < argv.size(); ++i) {
  77     CommandLine::StringType arg = argv[i];
  78     TrimWhitespace(arg, TRIM_ALL, &arg);
  79
  80     CommandLine::StringType switch_string;
  81     CommandLine::StringType switch_value;
  82     parse_switches &= (arg != kSwitchTerminator);
  83     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
  84 #if defined(OS_WIN)
  85       command_line.AppendSwitchNative(UTF16ToASCII(switch_string),
  86                                       switch_value);
  87 #elif defined(OS_POSIX)
  88       command_line.AppendSwitchNative(switch_string, switch_value);
  89 #endif
  90     } else {
  91       command_line.AppendArgNative(arg);
  92     }
  93   }
  94 }
  95
  96 // Lowercase switches for backwards compatiblity *on Windows*.
  97 std::string LowerASCIIOnWindows(const std::string& string) {
  98 #if defined(OS_WIN)
  99   return base::StringToLowerASCII(string);
 100 #elif defined(OS_POSIX)
 101   return string;
 102 #endif
 103 }
 104
 105
 106 #if defined(OS_WIN)
 107 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
 108 std::wstring QuoteForCommandLineToArgvW(const std::wstring& arg) {
 109   // We follow the quoting rules of CommandLineToArgvW.
 110   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 111   if (arg.find_first_of(L" \\\"") == std::wstring::npos) {
 112     // No quoting necessary.
 113     return arg;
 114   }
 115
 116   std::wstring out;
 117   out.push_back(L'"');
 118   for (size_t i = 0; i < arg.size(); ++i) {
 119     if (arg[i] == '\\') {
 120       // Find the extent of this run of backslashes.
 121       size_t start = i, end = start + 1;
 122       for (; end < arg.size() && arg[end] == '\\'; ++end)
 123         /* empty */;
 124       size_t backslash_count = end - start;
 125
 126       // Backslashes are escapes only if the run is followed by a double quote.
 127       // Since we also will end the string with a double quote, we escape for
 128       // either a double quote or the end of the string.
 129       if (end == arg.size() || arg[end] == '"') {
 130         // To quote, we need to output 2x as many backslashes.
 131         backslash_count *= 2;
 132       }
 133       for (size_t j = 0; j < backslash_count; ++j)
 134         out.push_back('\\');
 135
 136       // Advance i to one before the end to balance i++ in loop.
 137       i = end - 1;
 138     } else if (arg[i] == '"') {
 139       out.push_back('\\');
 140       out.push_back('"');
 141     } else {
 142       out.push_back(arg[i]);
 143     }
 144   }
 145   out.push_back('"');
 146
 147   return out;
 148 }
 149 #endif
 150
 151 }  // namespace
 152
 153 CommandLine::CommandLine(NoProgram no_program)
 154     : argv_(1),
 155       begin_args_(1) {
 156 }
 157
 158 CommandLine::CommandLine(const FilePath& program)
 159     : argv_(1),
 160       begin_args_(1) {
 161   SetProgram(program);
 162 }
 163
 164 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 165     : argv_(1),
 166       begin_args_(1) {
 167   InitFromArgv(argc, argv);
 168 }
 169
 170 CommandLine::CommandLine(const StringVector& argv)
 171     : argv_(1),
 172       begin_args_(1) {
 173   InitFromArgv(argv);
 174 }
 175
 176 CommandLine::~CommandLine() {
 177 }
 178
 179 #if defined(OS_WIN)
 180 // static
 181 void CommandLine::set_slash_is_not_a_switch() {
 182   // The last switch prefix should be slash, so adjust the size to skip it.
 183   DCHECK(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/") == 0);
 184   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
 185 }
 186 #endif
 187
 188 // static
 189 bool CommandLine::Init(int argc, const char* const* argv) {
 190   if (current_process_commandline_) {
 191     // If this is intentional, Reset() must be called first. If we are using
 192     // the shared build mode, we have to share a single object across multiple
 193     // shared libraries.
 194     return false;
 195   }
 196
 197   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 198 #if defined(OS_WIN)
 199   current_process_commandline_->ParseFromString(::GetCommandLineW());
 200 #elif defined(OS_POSIX)
 201   current_process_commandline_->InitFromArgv(argc, argv);
 202 #endif
 203
 204   return true;
 205 }
 206
 207 // static
 208 void CommandLine::Reset() {
 209   DCHECK(current_process_commandline_);
 210   delete current_process_commandline_;
 211   current_process_commandline_ = NULL;
 212 }
 213
 214 // static
 215 CommandLine* CommandLine::ForCurrentProcess() {
 216   DCHECK(current_process_commandline_);
 217   return current_process_commandline_;
 218 }
 219
 220 // static
 221 bool CommandLine::InitializedForCurrentProcess() {
 222   return !!current_process_commandline_;
 223 }
 224
 225 #if defined(OS_WIN)
 226 // static
 227 CommandLine CommandLine::FromString(const std::wstring& command_line) {
 228   CommandLine cmd(NO_PROGRAM);
 229   cmd.ParseFromString(command_line);
 230   return cmd;
 231 }
 232 #endif
 233
 234 void CommandLine::InitFromArgv(int argc,
 235                                const CommandLine::CharType* const* argv) {
 236   StringVector new_argv;
 237   for (int i = 0; i < argc; ++i)
 238     new_argv.push_back(argv[i]);
 239   InitFromArgv(new_argv);
 240 }
 241
 242 void CommandLine::InitFromArgv(const StringVector& argv) {
 243   argv_ = StringVector(1);
 244   switches_.clear();
 245   begin_args_ = 1;
 246   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 247   AppendSwitchesAndArguments(*this, argv);
 248 }
 249
 250 CommandLine::StringType CommandLine::GetCommandLineString() const {
 251   StringType string(argv_[0]);
 252 #if defined(OS_WIN)
 253   string = QuoteForCommandLineToArgvW(string);
 254 #endif
 255   StringType params(GetArgumentsString());
 256   if (!params.empty()) {
 257     string.append(StringType(FILE_PATH_LITERAL(" ")));
 258     string.append(params);
 259   }
 260   return string;
 261 }
 262
 263 CommandLine::StringType CommandLine::GetArgumentsString() const {
 264   StringType params;
 265   // Append switches and arguments.
 266   bool parse_switches = true;
 267   for (size_t i = 1; i < argv_.size(); ++i) {
 268     StringType arg = argv_[i];
 269     StringType switch_string;
 270     StringType switch_value;
 271     parse_switches &= arg != kSwitchTerminator;
 272     if (i > 1)
 273       params.append(StringType(FILE_PATH_LITERAL(" ")));
 274     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 275       params.append(switch_string);
 276       if (!switch_value.empty()) {
 277 #if defined(OS_WIN)
 278         switch_value = QuoteForCommandLineToArgvW(switch_value);
 279 #endif
 280         params.append(kSwitchValueSeparator + switch_value);
 281       }
 282     }
 283     else {
 284 #if defined(OS_WIN)
 285       arg = QuoteForCommandLineToArgvW(arg);
 286 #endif
 287       params.append(arg);
 288     }
 289   }
 290   return params;
 291 }
 292
 293 FilePath CommandLine::GetProgram() const {
 294   return FilePath(argv_[0]);
 295 }
 296
 297 void CommandLine::SetProgram(const FilePath& program) {
 298   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 299 }
 300
 301 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 302   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 303 }
 304
 305 std::string CommandLine::GetSwitchValueASCII(
 306     const std::string& switch_string) const {
 307   StringType value = GetSwitchValueNative(switch_string);
 308   if (!IsStringASCII(value)) {
 309     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 310     return std::string();
 311   }
 312 #if defined(OS_WIN)
 313   return UTF16ToASCII(value);
 314 #else
 315   return value;
 316 #endif
 317 }
 318
 319 FilePath CommandLine::GetSwitchValuePath(
 320     const std::string& switch_string) const {
 321   return FilePath(GetSwitchValueNative(switch_string));
 322 }
 323
 324 CommandLine::StringType CommandLine::GetSwitchValueNative(
 325     const std::string& switch_string) const {
 326   SwitchMap::const_iterator result =
 327     switches_.find(LowerASCIIOnWindows(switch_string));
 328   return result == switches_.end() ? StringType() : result->second;
 329 }
 330
 331 void CommandLine::AppendSwitch(const std::string& switch_string) {
 332   AppendSwitchNative(switch_string, StringType());
 333 }
 334
 335 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 336                                    const FilePath& path) {
 337   AppendSwitchNative(switch_string, path.value());
 338 }
 339
 340 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 341                                      const CommandLine::StringType& value) {
 342   std::string switch_key(LowerASCIIOnWindows(switch_string));
 343 #if defined(OS_WIN)
 344   StringType combined_switch_string(ASCIIToWide(switch_key));
 345 #elif defined(OS_POSIX)
 346   StringType combined_switch_string(switch_string);
 347 #endif
 348   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 349   switches_[switch_key.substr(prefix_length)] = value;
 350   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 351   if (prefix_length == 0)
 352     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 353   if (!value.empty())
 354     combined_switch_string += kSwitchValueSeparator + value;
 355   // Append the switch and update the switches/arguments divider |begin_args_|.
 356   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 357 }
 358
 359 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 360                                     const std::string& value_string) {
 361 #if defined(OS_WIN)
 362   AppendSwitchNative(switch_string, ASCIIToWide(value_string));
 363 #elif defined(OS_POSIX)
 364   AppendSwitchNative(switch_string, value_string);
 365 #endif
 366 }
 367
 368 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 369                                    const char* const switches[],
 370                                    size_t count) {
 371   for (size_t i = 0; i < count; ++i) {
 372     if (source.HasSwitch(switches[i]))
 373       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 374   }
 375 }
 376
 377 CommandLine::StringVector CommandLine::GetArgs() const {
 378   // Gather all arguments after the last switch (may include kSwitchTerminator).
 379   StringVector args(argv_.begin() + begin_args_, argv_.end());
 380   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 381   StringVector::iterator switch_terminator =
 382       std::find(args.begin(), args.end(), kSwitchTerminator);
 383   if (switch_terminator != args.end())
 384     args.erase(switch_terminator);
 385   return args;
 386 }
 387
 388 void CommandLine::AppendArg(const std::string& value) {
 389 #if defined(OS_WIN)
 390   DCHECK(IsStringUTF8(value));
 391   AppendArgNative(UTF8ToWide(value));
 392 #elif defined(OS_POSIX)
 393   AppendArgNative(value);
 394 #endif
 395 }
 396
 397 void CommandLine::AppendArgPath(const FilePath& path) {
 398   AppendArgNative(path.value());
 399 }
 400
 401 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 402   argv_.push_back(value);
 403 }
 404
 405 void CommandLine::AppendArguments(const CommandLine& other,
 406                                   bool include_program) {
 407   if (include_program)
 408     SetProgram(other.GetProgram());
 409   AppendSwitchesAndArguments(*this, other.argv());
 410 }
 411
 412 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 413   if (wrapper.empty())
 414     return;
 415   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 416   // we don't pretend to do anything fancy, we just split on spaces.
 417   StringVector wrapper_argv;
 418   SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 419   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 420   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 421   begin_args_ += wrapper_argv.size();
 422 }
 423
 424 #if defined(OS_WIN)
 425 void CommandLine::ParseFromString(const std::wstring& command_line) {
 426   std::wstring command_line_string;
 427   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 428   if (command_line_string.empty())
 429     return;
 430
 431   int num_args = 0;
 432   wchar_t** args = NULL;
 433   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 434
 435   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 436                          << UTF16ToUTF8(command_line);
 437   InitFromArgv(num_args, args);
 438   LocalFree(args);
 439 }
 440 #endif
 441
 442 }  // namespace base