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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 
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     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*.
LowerASCIIOnWindows(const std::string & string)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*.
QuoteForCommandLineToArgvW(const std::wstring & arg)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 
CommandLine(NoProgram no_program)153 CommandLine::CommandLine(NoProgram no_program)
154     : argv_(1),
155       begin_args_(1) {
156 }
157 
CommandLine(const FilePath & program)158 CommandLine::CommandLine(const FilePath& program)
159     : argv_(1),
160       begin_args_(1) {
161   SetProgram(program);
162 }
163 
CommandLine(int argc,const CommandLine::CharType * const * argv)164 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
165     : argv_(1),
166       begin_args_(1) {
167   InitFromArgv(argc, argv);
168 }
169 
CommandLine(const StringVector & argv)170 CommandLine::CommandLine(const StringVector& argv)
171     : argv_(1),
172       begin_args_(1) {
173   InitFromArgv(argv);
174 }
175 
~CommandLine()176 CommandLine::~CommandLine() {
177 }
178 
179 #if defined(OS_WIN)
180 // static
set_slash_is_not_a_switch()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
Init(int argc,const char * const * argv)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
Reset()208 void CommandLine::Reset() {
209   DCHECK(current_process_commandline_);
210   delete current_process_commandline_;
211   current_process_commandline_ = NULL;
212 }
213 
214 // static
ForCurrentProcess()215 CommandLine* CommandLine::ForCurrentProcess() {
216   DCHECK(current_process_commandline_);
217   return current_process_commandline_;
218 }
219 
220 // static
InitializedForCurrentProcess()221 bool CommandLine::InitializedForCurrentProcess() {
222   return !!current_process_commandline_;
223 }
224 
225 #if defined(OS_WIN)
226 // static
FromString(const std::wstring & command_line)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 
InitFromArgv(int argc,const CommandLine::CharType * const * argv)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 
InitFromArgv(const StringVector & argv)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 
GetCommandLineString() const250 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 
GetArgumentsString() const263 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 
GetProgram() const293 FilePath CommandLine::GetProgram() const {
294   return FilePath(argv_[0]);
295 }
296 
SetProgram(const FilePath & program)297 void CommandLine::SetProgram(const FilePath& program) {
298   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
299 }
300 
HasSwitch(const std::string & switch_string) const301 bool CommandLine::HasSwitch(const std::string& switch_string) const {
302   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
303 }
304 
GetSwitchValueASCII(const std::string & switch_string) const305 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 
GetSwitchValuePath(const std::string & switch_string) const319 FilePath CommandLine::GetSwitchValuePath(
320     const std::string& switch_string) const {
321   return FilePath(GetSwitchValueNative(switch_string));
322 }
323 
GetSwitchValueNative(const std::string & switch_string) const324 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 
AppendSwitch(const std::string & switch_string)331 void CommandLine::AppendSwitch(const std::string& switch_string) {
332   AppendSwitchNative(switch_string, StringType());
333 }
334 
AppendSwitchPath(const std::string & switch_string,const FilePath & path)335 void CommandLine::AppendSwitchPath(const std::string& switch_string,
336                                    const FilePath& path) {
337   AppendSwitchNative(switch_string, path.value());
338 }
339 
AppendSwitchNative(const std::string & switch_string,const CommandLine::StringType & value)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 
AppendSwitchASCII(const std::string & switch_string,const std::string & value_string)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 
CopySwitchesFrom(const CommandLine & source,const char * const switches[],size_t count)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 
GetArgs() const377 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 
AppendArg(const std::string & value)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 
AppendArgPath(const FilePath & path)397 void CommandLine::AppendArgPath(const FilePath& path) {
398   AppendArgNative(path.value());
399 }
400 
AppendArgNative(const CommandLine::StringType & value)401 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
402   argv_.push_back(value);
403 }
404 
AppendArguments(const CommandLine & other,bool include_program)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 
PrependWrapper(const CommandLine::StringType & wrapper)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)
ParseFromString(const std::wstring & command_line)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
443