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 #if defined(OS_WIN)
  98 std::string LowerASCIIOnWindows(const std::string& string) {
  99   return StringToLowerASCII(string);
 100 }
 101 #elif defined(OS_POSIX)
 102 const std::string& LowerASCIIOnWindows(const std::string& string) {
 103   return string;
 104 }
 105 #endif
 106
 107
 108 #if defined(OS_WIN)
 109 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
 110 string16 QuoteForCommandLineToArgvW(const string16& arg,
 111                                     bool quote_placeholders) {
 112   // We follow the quoting rules of CommandLineToArgvW.
 113   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 114   string16 quotable_chars(L" \\\"");
 115   // We may also be required to quote '%', which is commonly used in a command
 116   // line as a placeholder. (It may be substituted for a string with spaces.)
 117   if (quote_placeholders)
 118     quotable_chars.push_back(L'%');
 119   if (arg.find_first_of(quotable_chars) == string16::npos) {
 120     // No quoting necessary.
 121     return arg;
 122   }
 123
 124   string16 out;
 125   out.push_back(L'"');
 126   for (size_t i = 0; i < arg.size(); ++i) {
 127     if (arg[i] == '\\') {
 128       // Find the extent of this run of backslashes.
 129       size_t start = i, end = start + 1;
 130       for (; end < arg.size() && arg[end] == '\\'; ++end) {}
 131       size_t backslash_count = end - start;
 132
 133       // Backslashes are escapes only if the run is followed by a double quote.
 134       // Since we also will end the string with a double quote, we escape for
 135       // either a double quote or the end of the string.
 136       if (end == arg.size() || arg[end] == '"') {
 137         // To quote, we need to output 2x as many backslashes.
 138         backslash_count *= 2;
 139       }
 140       for (size_t j = 0; j < backslash_count; ++j)
 141         out.push_back('\\');
 142
 143       // Advance i to one before the end to balance i++ in loop.
 144       i = end - 1;
 145     } else if (arg[i] == '"') {
 146       out.push_back('\\');
 147       out.push_back('"');
 148     } else {
 149       out.push_back(arg[i]);
 150     }
 151   }
 152   out.push_back('"');
 153
 154   return out;
 155 }
 156 #endif
 157
 158 }  // namespace
 159
 160 CommandLine::CommandLine(NoProgram no_program)
 161     : argv_(1),
 162       begin_args_(1) {
 163 }
 164
 165 CommandLine::CommandLine(const FilePath& program)
 166     : argv_(1),
 167       begin_args_(1) {
 168   SetProgram(program);
 169 }
 170
 171 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 172     : argv_(1),
 173       begin_args_(1) {
 174   InitFromArgv(argc, argv);
 175 }
 176
 177 CommandLine::CommandLine(const StringVector& argv)
 178     : argv_(1),
 179       begin_args_(1) {
 180   InitFromArgv(argv);
 181 }
 182
 183 CommandLine::~CommandLine() {
 184 }
 185
 186 #if defined(OS_WIN)
 187 // static
 188 void CommandLine::set_slash_is_not_a_switch() {
 189   // The last switch prefix should be slash, so adjust the size to skip it.
 190   DCHECK(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/") == 0);
 191   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
 192 }
 193 #endif
 194
 195 // static
 196 bool CommandLine::Init(int argc, const char* const* argv) {
 197   if (current_process_commandline_) {
 198     // If this is intentional, Reset() must be called first. If we are using
 199     // the shared build mode, we have to share a single object across multiple
 200     // shared libraries.
 201     return false;
 202   }
 203
 204   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 205 #if defined(OS_WIN)
 206   current_process_commandline_->ParseFromString(::GetCommandLineW());
 207 #elif defined(OS_POSIX)
 208   current_process_commandline_->InitFromArgv(argc, argv);
 209 #endif
 210
 211   return true;
 212 }
 213
 214 // static
 215 void CommandLine::Reset() {
 216   DCHECK(current_process_commandline_);
 217   delete current_process_commandline_;
 218   current_process_commandline_ = NULL;
 219 }
 220
 221 // static
 222 CommandLine* CommandLine::ForCurrentProcess() {
 223   DCHECK(current_process_commandline_);
 224   return current_process_commandline_;
 225 }
 226
 227 // static
 228 bool CommandLine::InitializedForCurrentProcess() {
 229   return !!current_process_commandline_;
 230 }
 231
 232 #if defined(OS_WIN)
 233 // static
 234 CommandLine CommandLine::FromString(const string16& command_line) {
 235   CommandLine cmd(NO_PROGRAM);
 236   cmd.ParseFromString(command_line);
 237   return cmd;
 238 }
 239 #endif
 240
 241 void CommandLine::InitFromArgv(int argc,
 242                                const CommandLine::CharType* const* argv) {
 243   StringVector new_argv;
 244   for (int i = 0; i < argc; ++i)
 245     new_argv.push_back(argv[i]);
 246   InitFromArgv(new_argv);
 247 }
 248
 249 void CommandLine::InitFromArgv(const StringVector& argv) {
 250   argv_ = StringVector(1);
 251   switches_.clear();
 252   begin_args_ = 1;
 253   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 254   AppendSwitchesAndArguments(this, argv);
 255 }
 256
 257 FilePath CommandLine::GetProgram() const {
 258   return FilePath(argv_[0]);
 259 }
 260
 261 void CommandLine::SetProgram(const FilePath& program) {
 262   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 263 }
 264
 265 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 266   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 267 }
 268
 269 std::string CommandLine::GetSwitchValueASCII(
 270     const std::string& switch_string) const {
 271   StringType value = GetSwitchValueNative(switch_string);
 272   if (!IsStringASCII(value)) {
 273     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 274     return std::string();
 275   }
 276 #if defined(OS_WIN)
 277   return UTF16ToASCII(value);
 278 #else
 279   return value;
 280 #endif
 281 }
 282
 283 FilePath CommandLine::GetSwitchValuePath(
 284     const std::string& switch_string) const {
 285   return FilePath(GetSwitchValueNative(switch_string));
 286 }
 287
 288 CommandLine::StringType CommandLine::GetSwitchValueNative(
 289     const std::string& switch_string) const {
 290   SwitchMap::const_iterator result =
 291     switches_.find(LowerASCIIOnWindows(switch_string));
 292   return result == switches_.end() ? StringType() : result->second;
 293 }
 294
 295 void CommandLine::AppendSwitch(const std::string& switch_string) {
 296   AppendSwitchNative(switch_string, StringType());
 297 }
 298
 299 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 300                                    const FilePath& path) {
 301   AppendSwitchNative(switch_string, path.value());
 302 }
 303
 304 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 305                                      const CommandLine::StringType& value) {
 306   std::string switch_key(LowerASCIIOnWindows(switch_string));
 307 #if defined(OS_WIN)
 308   StringType combined_switch_string(ASCIIToUTF16(switch_key));
 309 #elif defined(OS_POSIX)
 310   StringType combined_switch_string(switch_string);
 311 #endif
 312   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 313   switches_[switch_key.substr(prefix_length)] = value;
 314   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 315   if (prefix_length == 0)
 316     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 317   if (!value.empty())
 318     combined_switch_string += kSwitchValueSeparator + value;
 319   // Append the switch and update the switches/arguments divider |begin_args_|.
 320   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 321 }
 322
 323 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 324                                     const std::string& value_string) {
 325 #if defined(OS_WIN)
 326   AppendSwitchNative(switch_string, ASCIIToUTF16(value_string));
 327 #elif defined(OS_POSIX)
 328   AppendSwitchNative(switch_string, value_string);
 329 #endif
 330 }
 331
 332 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 333                                    const char* const switches[],
 334                                    size_t count) {
 335   for (size_t i = 0; i < count; ++i) {
 336     if (source.HasSwitch(switches[i]))
 337       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 338   }
 339 }
 340
 341 CommandLine::StringVector CommandLine::GetArgs() const {
 342   // Gather all arguments after the last switch (may include kSwitchTerminator).
 343   StringVector args(argv_.begin() + begin_args_, argv_.end());
 344   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 345   StringVector::iterator switch_terminator =
 346       std::find(args.begin(), args.end(), kSwitchTerminator);
 347   if (switch_terminator != args.end())
 348     args.erase(switch_terminator);
 349   return args;
 350 }
 351
 352 void CommandLine::AppendArg(const std::string& value) {
 353 #if defined(OS_WIN)
 354   DCHECK(IsStringUTF8(value));
 355   AppendArgNative(UTF8ToWide(value));
 356 #elif defined(OS_POSIX)
 357   AppendArgNative(value);
 358 #endif
 359 }
 360
 361 void CommandLine::AppendArgPath(const FilePath& path) {
 362   AppendArgNative(path.value());
 363 }
 364
 365 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 366   argv_.push_back(value);
 367 }
 368
 369 void CommandLine::AppendArguments(const CommandLine& other,
 370                                   bool include_program) {
 371   if (include_program)
 372     SetProgram(other.GetProgram());
 373   AppendSwitchesAndArguments(this, other.argv());
 374 }
 375
 376 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 377   if (wrapper.empty())
 378     return;
 379   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 380   // we don't pretend to do anything fancy, we just split on spaces.
 381   StringVector wrapper_argv;
 382   SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 383   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 384   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 385   begin_args_ += wrapper_argv.size();
 386 }
 387
 388 #if defined(OS_WIN)
 389 void CommandLine::ParseFromString(const string16& command_line) {
 390   string16 command_line_string;
 391   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 392   if (command_line_string.empty())
 393     return;
 394
 395   int num_args = 0;
 396   wchar_t** args = NULL;
 397   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 398
 399   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 400                          << UTF16ToUTF8(command_line);
 401   InitFromArgv(num_args, args);
 402   LocalFree(args);
 403 }
 404 #endif
 405
 406 CommandLine::StringType CommandLine::GetCommandLineStringInternal(
 407     bool quote_placeholders) const {
 408   StringType string(argv_[0]);
 409 #if defined(OS_WIN)
 410   string = QuoteForCommandLineToArgvW(string, quote_placeholders);
 411 #endif
 412   StringType params(GetArgumentsStringInternal(quote_placeholders));
 413   if (!params.empty()) {
 414     string.append(StringType(FILE_PATH_LITERAL(" ")));
 415     string.append(params);
 416   }
 417   return string;
 418 }
 419
 420 CommandLine::StringType CommandLine::GetArgumentsStringInternal(
 421     bool quote_placeholders) const {
 422   StringType params;
 423   // Append switches and arguments.
 424   bool parse_switches = true;
 425   for (size_t i = 1; i < argv_.size(); ++i) {
 426     StringType arg = argv_[i];
 427     StringType switch_string;
 428     StringType switch_value;
 429     parse_switches &= arg != kSwitchTerminator;
 430     if (i > 1)
 431       params.append(StringType(FILE_PATH_LITERAL(" ")));
 432     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 433       params.append(switch_string);
 434       if (!switch_value.empty()) {
 435 #if defined(OS_WIN)
 436         switch_value =
 437             QuoteForCommandLineToArgvW(switch_value, quote_placeholders);
 438 #endif
 439         params.append(kSwitchValueSeparator + switch_value);
 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