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/files/file_path.h"
11 #include "base/logging.h"
12 #include "base/macros.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 
GetSwitchPrefixLength(const CommandLine::StringType & string)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|.
IsSwitch(const CommandLine::StringType & string,CommandLine::StringType * switch_string,CommandLine::StringType * switch_value)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.
AppendSwitchesAndArguments(CommandLine * command_line,const CommandLine::StringVector & argv)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 #if defined(OS_WIN)
79     TrimWhitespace(arg, TRIM_ALL, &arg);
80 #else
81     TrimWhitespaceASCII(arg, TRIM_ALL, &arg);
82 #endif
83 
84     CommandLine::StringType switch_string;
85     CommandLine::StringType switch_value;
86     parse_switches &= (arg != kSwitchTerminator);
87     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
88 #if defined(OS_WIN)
89       command_line->AppendSwitchNative(UTF16ToASCII(switch_string),
90                                        switch_value);
91 #elif defined(OS_POSIX)
92       command_line->AppendSwitchNative(switch_string, switch_value);
93 #endif
94     } else {
95       command_line->AppendArgNative(arg);
96     }
97   }
98 }
99 
100 #if defined(OS_WIN)
101 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
QuoteForCommandLineToArgvW(const string16 & arg,bool quote_placeholders)102 string16 QuoteForCommandLineToArgvW(const string16& arg,
103                                     bool quote_placeholders) {
104   // We follow the quoting rules of CommandLineToArgvW.
105   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
106   string16 quotable_chars(L" \\\"");
107   // We may also be required to quote '%', which is commonly used in a command
108   // line as a placeholder. (It may be substituted for a string with spaces.)
109   if (quote_placeholders)
110     quotable_chars.push_back(L'%');
111   if (arg.find_first_of(quotable_chars) == string16::npos) {
112     // No quoting necessary.
113     return arg;
114   }
115 
116   string16 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       size_t backslash_count = end - start;
124 
125       // Backslashes are escapes only if the run is followed by a double quote.
126       // Since we also will end the string with a double quote, we escape for
127       // either a double quote or the end of the string.
128       if (end == arg.size() || arg[end] == '"') {
129         // To quote, we need to output 2x as many backslashes.
130         backslash_count *= 2;
131       }
132       for (size_t j = 0; j < backslash_count; ++j)
133         out.push_back('\\');
134 
135       // Advance i to one before the end to balance i++ in loop.
136       i = end - 1;
137     } else if (arg[i] == '"') {
138       out.push_back('\\');
139       out.push_back('"');
140     } else {
141       out.push_back(arg[i]);
142     }
143   }
144   out.push_back('"');
145 
146   return out;
147 }
148 #endif
149 
150 }  // namespace
151 
CommandLine(NoProgram)152 CommandLine::CommandLine(NoProgram /* no_program */)
153     : argv_(1),
154       begin_args_(1) {
155 }
156 
CommandLine(const FilePath & program)157 CommandLine::CommandLine(const FilePath& program)
158     : argv_(1),
159       begin_args_(1) {
160   SetProgram(program);
161 }
162 
CommandLine(int argc,const CommandLine::CharType * const * argv)163 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
164     : argv_(1),
165       begin_args_(1) {
166   InitFromArgv(argc, argv);
167 }
168 
CommandLine(const StringVector & argv)169 CommandLine::CommandLine(const StringVector& argv)
170     : argv_(1),
171       begin_args_(1) {
172   InitFromArgv(argv);
173 }
174 
CommandLine(const CommandLine & other)175 CommandLine::CommandLine(const CommandLine& other)
176     : argv_(other.argv_),
177       switches_(other.switches_),
178       begin_args_(other.begin_args_) {
179   ResetStringPieces();
180 }
181 
operator =(const CommandLine & other)182 CommandLine& CommandLine::operator=(const CommandLine& other) {
183   argv_ = other.argv_;
184   switches_ = other.switches_;
185   begin_args_ = other.begin_args_;
186   ResetStringPieces();
187   return *this;
188 }
189 
~CommandLine()190 CommandLine::~CommandLine() {
191 }
192 
193 #if defined(OS_WIN)
194 // static
set_slash_is_not_a_switch()195 void CommandLine::set_slash_is_not_a_switch() {
196   // The last switch prefix should be slash, so adjust the size to skip it.
197   DCHECK_EQ(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/"), 0);
198   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
199 }
200 #endif
201 
202 // static
Init(int argc,const char * const * argv)203 bool CommandLine::Init(int argc, const char* const* argv) {
204   if (current_process_commandline_) {
205     // If this is intentional, Reset() must be called first. If we are using
206     // the shared build mode, we have to share a single object across multiple
207     // shared libraries.
208     return false;
209   }
210 
211   current_process_commandline_ = new CommandLine(NO_PROGRAM);
212 #if defined(OS_WIN)
213   current_process_commandline_->ParseFromString(::GetCommandLineW());
214 #elif defined(OS_POSIX)
215   current_process_commandline_->InitFromArgv(argc, argv);
216 #endif
217 
218   return true;
219 }
220 
221 // static
Reset()222 void CommandLine::Reset() {
223   DCHECK(current_process_commandline_);
224   delete current_process_commandline_;
225   current_process_commandline_ = NULL;
226 }
227 
228 // static
ForCurrentProcess()229 CommandLine* CommandLine::ForCurrentProcess() {
230   DCHECK(current_process_commandline_);
231   return current_process_commandline_;
232 }
233 
234 // static
InitializedForCurrentProcess()235 bool CommandLine::InitializedForCurrentProcess() {
236   return !!current_process_commandline_;
237 }
238 
239 #if defined(OS_WIN)
240 // static
FromString(const string16 & command_line)241 CommandLine CommandLine::FromString(const string16& command_line) {
242   CommandLine cmd(NO_PROGRAM);
243   cmd.ParseFromString(command_line);
244   return cmd;
245 }
246 #endif
247 
InitFromArgv(int argc,const CommandLine::CharType * const * argv)248 void CommandLine::InitFromArgv(int argc,
249                                const CommandLine::CharType* const* argv) {
250   StringVector new_argv;
251   for (int i = 0; i < argc; ++i)
252     new_argv.push_back(argv[i]);
253   InitFromArgv(new_argv);
254 }
255 
InitFromArgv(const StringVector & argv)256 void CommandLine::InitFromArgv(const StringVector& argv) {
257   argv_ = StringVector(1);
258   switches_.clear();
259   switches_by_stringpiece_.clear();
260   begin_args_ = 1;
261   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
262   AppendSwitchesAndArguments(this, argv);
263 }
264 
GetProgram() const265 FilePath CommandLine::GetProgram() const {
266   return FilePath(argv_[0]);
267 }
268 
SetProgram(const FilePath & program)269 void CommandLine::SetProgram(const FilePath& program) {
270 #if defined(OS_WIN)
271   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
272 #else
273   TrimWhitespaceASCII(program.value(), TRIM_ALL, &argv_[0]);
274 #endif
275 }
276 
HasSwitch(const base::StringPiece & switch_string) const277 bool CommandLine::HasSwitch(const base::StringPiece& switch_string) const {
278   DCHECK_EQ(ToLowerASCII(switch_string), switch_string);
279   return switches_by_stringpiece_.find(switch_string) !=
280          switches_by_stringpiece_.end();
281 }
282 
HasSwitch(const char switch_constant[]) const283 bool CommandLine::HasSwitch(const char switch_constant[]) const {
284   return HasSwitch(base::StringPiece(switch_constant));
285 }
286 
GetSwitchValueASCII(const base::StringPiece & switch_string) const287 std::string CommandLine::GetSwitchValueASCII(
288     const base::StringPiece& switch_string) const {
289   StringType value = GetSwitchValueNative(switch_string);
290   if (!IsStringASCII(value)) {
291     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
292     return std::string();
293   }
294 #if defined(OS_WIN)
295   return UTF16ToASCII(value);
296 #else
297   return value;
298 #endif
299 }
300 
GetSwitchValuePath(const base::StringPiece & switch_string) const301 FilePath CommandLine::GetSwitchValuePath(
302     const base::StringPiece& switch_string) const {
303   return FilePath(GetSwitchValueNative(switch_string));
304 }
305 
GetSwitchValueNative(const base::StringPiece & switch_string) const306 CommandLine::StringType CommandLine::GetSwitchValueNative(
307     const base::StringPiece& switch_string) const {
308   DCHECK_EQ(ToLowerASCII(switch_string), switch_string);
309   auto result = switches_by_stringpiece_.find(switch_string);
310   return result == switches_by_stringpiece_.end() ? StringType()
311                                                   : *(result->second);
312 }
313 
AppendSwitch(const std::string & switch_string)314 void CommandLine::AppendSwitch(const std::string& switch_string) {
315   AppendSwitchNative(switch_string, StringType());
316 }
317 
AppendSwitchPath(const std::string & switch_string,const FilePath & path)318 void CommandLine::AppendSwitchPath(const std::string& switch_string,
319                                    const FilePath& path) {
320   AppendSwitchNative(switch_string, path.value());
321 }
322 
AppendSwitchNative(const std::string & switch_string,const CommandLine::StringType & value)323 void CommandLine::AppendSwitchNative(const std::string& switch_string,
324                                      const CommandLine::StringType& value) {
325 #if defined(OS_WIN)
326   const std::string switch_key = ToLowerASCII(switch_string);
327   StringType combined_switch_string(ASCIIToUTF16(switch_key));
328 #elif defined(OS_POSIX)
329   const std::string& switch_key = switch_string;
330   StringType combined_switch_string(switch_key);
331 #endif
332   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
333   auto insertion =
334       switches_.insert(make_pair(switch_key.substr(prefix_length), value));
335   if (!insertion.second)
336     insertion.first->second = value;
337   switches_by_stringpiece_[insertion.first->first] = &(insertion.first->second);
338   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
339   if (prefix_length == 0)
340     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
341   if (!value.empty())
342     combined_switch_string += kSwitchValueSeparator + value;
343   // Append the switch and update the switches/arguments divider |begin_args_|.
344   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
345 }
346 
AppendSwitchASCII(const std::string & switch_string,const std::string & value_string)347 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
348                                     const std::string& value_string) {
349 #if defined(OS_WIN)
350   AppendSwitchNative(switch_string, ASCIIToUTF16(value_string));
351 #elif defined(OS_POSIX)
352   AppendSwitchNative(switch_string, value_string);
353 #endif
354 }
355 
CopySwitchesFrom(const CommandLine & source,const char * const switches[],size_t count)356 void CommandLine::CopySwitchesFrom(const CommandLine& source,
357                                    const char* const switches[],
358                                    size_t count) {
359   for (size_t i = 0; i < count; ++i) {
360     if (source.HasSwitch(switches[i]))
361       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
362   }
363 }
364 
GetArgs() const365 CommandLine::StringVector CommandLine::GetArgs() const {
366   // Gather all arguments after the last switch (may include kSwitchTerminator).
367   StringVector args(argv_.begin() + begin_args_, argv_.end());
368   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
369   StringVector::iterator switch_terminator =
370       std::find(args.begin(), args.end(), kSwitchTerminator);
371   if (switch_terminator != args.end())
372     args.erase(switch_terminator);
373   return args;
374 }
375 
AppendArg(const std::string & value)376 void CommandLine::AppendArg(const std::string& value) {
377 #if defined(OS_WIN)
378   DCHECK(IsStringUTF8(value));
379   AppendArgNative(UTF8ToWide(value));
380 #elif defined(OS_POSIX)
381   AppendArgNative(value);
382 #endif
383 }
384 
AppendArgPath(const FilePath & path)385 void CommandLine::AppendArgPath(const FilePath& path) {
386   AppendArgNative(path.value());
387 }
388 
AppendArgNative(const CommandLine::StringType & value)389 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
390   argv_.push_back(value);
391 }
392 
AppendArguments(const CommandLine & other,bool include_program)393 void CommandLine::AppendArguments(const CommandLine& other,
394                                   bool include_program) {
395   if (include_program)
396     SetProgram(other.GetProgram());
397   AppendSwitchesAndArguments(this, other.argv());
398 }
399 
PrependWrapper(const CommandLine::StringType & wrapper)400 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
401   if (wrapper.empty())
402     return;
403   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
404   // we don't pretend to do anything fancy, we just split on spaces.
405   StringVector wrapper_argv = SplitString(
406       wrapper, FilePath::StringType(1, ' '), base::TRIM_WHITESPACE,
407       base::SPLIT_WANT_ALL);
408   // Prepend the wrapper and update the switches/arguments |begin_args_|.
409   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
410   begin_args_ += wrapper_argv.size();
411 }
412 
413 #if defined(OS_WIN)
ParseFromString(const string16 & command_line)414 void CommandLine::ParseFromString(const string16& command_line) {
415   string16 command_line_string;
416   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
417   if (command_line_string.empty())
418     return;
419 
420   int num_args = 0;
421   wchar_t** args = NULL;
422   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
423 
424   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
425                          << UTF16ToUTF8(command_line);
426   InitFromArgv(num_args, args);
427   LocalFree(args);
428 }
429 #endif
430 
GetCommandLineStringInternal(bool quote_placeholders) const431 CommandLine::StringType CommandLine::GetCommandLineStringInternal(
432     bool quote_placeholders) const {
433   StringType string(argv_[0]);
434 #if defined(OS_WIN)
435   string = QuoteForCommandLineToArgvW(string, quote_placeholders);
436 #endif
437   StringType params(GetArgumentsStringInternal(quote_placeholders));
438   if (!params.empty()) {
439     string.append(StringType(FILE_PATH_LITERAL(" ")));
440     string.append(params);
441   }
442   return string;
443 }
444 
GetArgumentsStringInternal(bool) const445 CommandLine::StringType CommandLine::GetArgumentsStringInternal(
446     bool /* quote_placeholders */) const {
447   StringType params;
448   // Append switches and arguments.
449   bool parse_switches = true;
450   for (size_t i = 1; i < argv_.size(); ++i) {
451     StringType arg = argv_[i];
452     StringType switch_string;
453     StringType switch_value;
454     parse_switches &= arg != kSwitchTerminator;
455     if (i > 1)
456       params.append(StringType(FILE_PATH_LITERAL(" ")));
457     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
458       params.append(switch_string);
459       if (!switch_value.empty()) {
460 #if defined(OS_WIN)
461         switch_value =
462             QuoteForCommandLineToArgvW(switch_value, quote_placeholders);
463 #endif
464         params.append(kSwitchValueSeparator + switch_value);
465       }
466     } else {
467 #if defined(OS_WIN)
468       arg = QuoteForCommandLineToArgvW(arg, quote_placeholders);
469 #endif
470       params.append(arg);
471     }
472   }
473   return params;
474 }
475 
ResetStringPieces()476 void CommandLine::ResetStringPieces() {
477   switches_by_stringpiece_.clear();
478   for (const auto& entry : switches_)
479     switches_by_stringpiece_[entry.first] = &(entry.second);
480 }
481 
482 }  // namespace base
483