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 base::string16 QuoteForCommandLineToArgvW(const base::string16& arg,
 109                                           bool quote_placeholders) {
 110   // We follow the quoting rules of CommandLineToArgvW.
 111   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 112   base::string16 quotable_chars(L" \\\"");
 113   // We may also be required to quote '%', which is commonly used in a command
 114   // line as a placeholder. (It may be substituted for a string with spaces.)
 115   if (quote_placeholders)
 116     quotable_chars.push_back(L'%');
 117   if (arg.find_first_of(quotable_chars) == base::string16::npos) {
 118     // No quoting necessary.
 119     return arg;
 120   }
 121
 122   base::string16 out;
 123   out.push_back(L'"');
 124   for (size_t i = 0; i < arg.size(); ++i) {
 125     if (arg[i] == '\\') {
 126       // Find the extent of this run of backslashes.
 127       size_t start = i, end = start + 1;
 128       for (; end < arg.size() && arg[end] == '\\'; ++end)
 129         /* empty */;
 130       size_t backslash_count = end - start;
 131
 132       // Backslashes are escapes only if the run is followed by a double quote.
 133       // Since we also will end the string with a double quote, we escape for
 134       // either a double quote or the end of the string.
 135       if (end == arg.size() || arg[end] == '"') {
 136         // To quote, we need to output 2x as many backslashes.
 137         backslash_count *= 2;
 138       }
 139       for (size_t j = 0; j < backslash_count; ++j)
 140         out.push_back('\\');
 141
 142       // Advance i to one before the end to balance i++ in loop.
 143       i = end - 1;
 144     } else if (arg[i] == '"') {
 145       out.push_back('\\');
 146       out.push_back('"');
 147     } else {
 148       out.push_back(arg[i]);
 149     }
 150   }
 151   out.push_back('"');
 152
 153   return out;
 154 }
 155 #endif
 156
 157 }  // namespace
 158
 159 CommandLine::CommandLine(NoProgram no_program)
 160     : argv_(1),
 161       begin_args_(1) {
 162 }
 163
 164 CommandLine::CommandLine(const FilePath& program)
 165     : argv_(1),
 166       begin_args_(1) {
 167   SetProgram(program);
 168 }
 169
 170 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 171     : argv_(1),
 172       begin_args_(1) {
 173   InitFromArgv(argc, argv);
 174 }
 175
 176 CommandLine::CommandLine(const StringVector& argv)
 177     : argv_(1),
 178       begin_args_(1) {
 179   InitFromArgv(argv);
 180 }
 181
 182 CommandLine::~CommandLine() {
 183 }
 184
 185 #if defined(OS_WIN)
 186 // static
 187 void CommandLine::set_slash_is_not_a_switch() {
 188   // The last switch prefix should be slash, so adjust the size to skip it.
 189   DCHECK(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/") == 0);
 190   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
 191 }
 192 #endif
 193
 194 // static
 195 bool CommandLine::Init(int argc, const char* const* argv) {
 196   if (current_process_commandline_) {
 197     // If this is intentional, Reset() must be called first. If we are using
 198     // the shared build mode, we have to share a single object across multiple
 199     // shared libraries.
 200     return false;
 201   }
 202
 203   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 204 #if defined(OS_WIN)
 205   current_process_commandline_->ParseFromString(::GetCommandLineW());
 206 #elif defined(OS_POSIX)
 207   current_process_commandline_->InitFromArgv(argc, argv);
 208 #endif
 209
 210   return true;
 211 }
 212
 213 // static
 214 void CommandLine::Reset() {
 215   DCHECK(current_process_commandline_);
 216   delete current_process_commandline_;
 217   current_process_commandline_ = NULL;
 218 }
 219
 220 // static
 221 CommandLine* CommandLine::ForCurrentProcess() {
 222   DCHECK(current_process_commandline_);
 223   return current_process_commandline_;
 224 }
 225
 226 // static
 227 bool CommandLine::InitializedForCurrentProcess() {
 228   return !!current_process_commandline_;
 229 }
 230
 231 #if defined(OS_WIN)
 232 // static
 233 CommandLine CommandLine::FromString(const base::string16& command_line) {
 234   CommandLine cmd(NO_PROGRAM);
 235   cmd.ParseFromString(command_line);
 236   return cmd;
 237 }
 238 #endif
 239
 240 void CommandLine::InitFromArgv(int argc,
 241                                const CommandLine::CharType* const* argv) {
 242   StringVector new_argv;
 243   for (int i = 0; i < argc; ++i)
 244     new_argv.push_back(argv[i]);
 245   InitFromArgv(new_argv);
 246 }
 247
 248 void CommandLine::InitFromArgv(const StringVector& argv) {
 249   argv_ = StringVector(1);
 250   switches_.clear();
 251   begin_args_ = 1;
 252   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 253   AppendSwitchesAndArguments(*this, argv);
 254 }
 255
 256 FilePath CommandLine::GetProgram() const {
 257   return FilePath(argv_[0]);
 258 }
 259
 260 void CommandLine::SetProgram(const FilePath& program) {
 261   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 262 }
 263
 264 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 265   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 266 }
 267
 268 std::string CommandLine::GetSwitchValueASCII(
 269     const std::string& switch_string) const {
 270   StringType value = GetSwitchValueNative(switch_string);
 271   if (!IsStringASCII(value)) {
 272     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 273     return std::string();
 274   }
 275 #if defined(OS_WIN)
 276   return UTF16ToASCII(value);
 277 #else
 278   return value;
 279 #endif
 280 }
 281
 282 FilePath CommandLine::GetSwitchValuePath(
 283     const std::string& switch_string) const {
 284   return FilePath(GetSwitchValueNative(switch_string));
 285 }
 286
 287 CommandLine::StringType CommandLine::GetSwitchValueNative(
 288     const std::string& switch_string) const {
 289   SwitchMap::const_iterator result =
 290     switches_.find(LowerASCIIOnWindows(switch_string));
 291   return result == switches_.end() ? StringType() : result->second;
 292 }
 293
 294 void CommandLine::AppendSwitch(const std::string& switch_string) {
 295   AppendSwitchNative(switch_string, StringType());
 296 }
 297
 298 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 299                                    const FilePath& path) {
 300   AppendSwitchNative(switch_string, path.value());
 301 }
 302
 303 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 304                                      const CommandLine::StringType& value) {
 305   std::string switch_key(LowerASCIIOnWindows(switch_string));
 306 #if defined(OS_WIN)
 307   StringType combined_switch_string(ASCIIToWide(switch_key));
 308 #elif defined(OS_POSIX)
 309   StringType combined_switch_string(switch_string);
 310 #endif
 311   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 312   switches_[switch_key.substr(prefix_length)] = value;
 313   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 314   if (prefix_length == 0)
 315     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 316   if (!value.empty())
 317     combined_switch_string += kSwitchValueSeparator + value;
 318   // Append the switch and update the switches/arguments divider |begin_args_|.
 319   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 320 }
 321
 322 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 323                                     const std::string& value_string) {
 324 #if defined(OS_WIN)
 325   AppendSwitchNative(switch_string, ASCIIToWide(value_string));
 326 #elif defined(OS_POSIX)
 327   AppendSwitchNative(switch_string, value_string);
 328 #endif
 329 }
 330
 331 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 332                                    const char* const switches[],
 333                                    size_t count) {
 334   for (size_t i = 0; i < count; ++i) {
 335     if (source.HasSwitch(switches[i]))
 336       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 337   }
 338 }
 339
 340 CommandLine::StringVector CommandLine::GetArgs() const {
 341   // Gather all arguments after the last switch (may include kSwitchTerminator).
 342   StringVector args(argv_.begin() + begin_args_, argv_.end());
 343   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 344   StringVector::iterator switch_terminator =
 345       std::find(args.begin(), args.end(), kSwitchTerminator);
 346   if (switch_terminator != args.end())
 347     args.erase(switch_terminator);
 348   return args;
 349 }
 350
 351 void CommandLine::AppendArg(const std::string& value) {
 352 #if defined(OS_WIN)
 353   DCHECK(IsStringUTF8(value));
 354   AppendArgNative(UTF8ToWide(value));
 355 #elif defined(OS_POSIX)
 356   AppendArgNative(value);
 357 #endif
 358 }
 359
 360 void CommandLine::AppendArgPath(const FilePath& path) {
 361   AppendArgNative(path.value());
 362 }
 363
 364 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 365   argv_.push_back(value);
 366 }
 367
 368 void CommandLine::AppendArguments(const CommandLine& other,
 369                                   bool include_program) {
 370   if (include_program)
 371     SetProgram(other.GetProgram());
 372   AppendSwitchesAndArguments(*this, other.argv());
 373 }
 374
 375 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 376   if (wrapper.empty())
 377     return;
 378   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 379   // we don't pretend to do anything fancy, we just split on spaces.
 380   StringVector wrapper_argv;
 381   SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 382   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 383   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 384   begin_args_ += wrapper_argv.size();
 385 }
 386
 387 #if defined(OS_WIN)
 388 void CommandLine::ParseFromString(const base::string16& command_line) {
 389   base::string16 command_line_string;
 390   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 391   if (command_line_string.empty())
 392     return;
 393
 394   int num_args = 0;
 395   wchar_t** args = NULL;
 396   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 397
 398   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 399                          << UTF16ToUTF8(command_line);
 400   InitFromArgv(num_args, args);
 401   LocalFree(args);
 402 }
 403 #endif
 404
 405 CommandLine::StringType CommandLine::GetCommandLineStringInternal(
 406     bool quote_placeholders) const {
 407   StringType string(argv_[0]);
 408 #if defined(OS_WIN)
 409   string = QuoteForCommandLineToArgvW(string, quote_placeholders);
 410 #endif
 411   StringType params(GetArgumentsStringInternal(quote_placeholders));
 412   if (!params.empty()) {
 413     string.append(StringType(FILE_PATH_LITERAL(" ")));
 414     string.append(params);
 415   }
 416   return string;
 417 }
 418
 419 CommandLine::StringType CommandLine::GetArgumentsStringInternal(
 420     bool quote_placeholders) const {
 421   StringType params;
 422   // Append switches and arguments.
 423   bool parse_switches = true;
 424   for (size_t i = 1; i < argv_.size(); ++i) {
 425     StringType arg = argv_[i];
 426     StringType switch_string;
 427     StringType switch_value;
 428     parse_switches &= arg != kSwitchTerminator;
 429     if (i > 1)
 430       params.append(StringType(FILE_PATH_LITERAL(" ")));
 431     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 432       params.append(switch_string);
 433       if (!switch_value.empty()) {
 434 #if defined(OS_WIN)
 435         switch_value =
 436             QuoteForCommandLineToArgvW(switch_value, quote_placeholders);
 437 #endif
 438         params.append(kSwitchValueSeparator + switch_value);
 439       }
 440     }
 441     else {
 442 #if defined(OS_WIN)
 443       arg = QuoteForCommandLineToArgvW(arg, quote_placeholders);
 444 #endif
 445       params.append(arg);
 446     }
 447   }
 448   return params;
 449 }
 450
 451 }  // namespace base