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.
5 // This class works with command lines: building and parsing.
6 // Arguments with prefixes ('--', '-', and on Windows, '/') are switches.
7 // Switches will precede all other arguments without switch prefixes.
8 // Switches can optionally have values, delimited by '=', e.g., "-switch=value".
9 // If a switch is specified multiple times, only the last value is used.
10 // An argument of "--" will terminate switch parsing during initialization,
11 // interpreting subsequent tokens as non-switch arguments, regardless of prefix.
13 // There is a singleton read-only CommandLine that represents the command line
14 // that the current process was started with. It must be initialized in main().
16 #ifndef BASE_COMMAND_LINE_H_
17 #define BASE_COMMAND_LINE_H_
24 #include "base/base_export.h"
25 #include "base/strings/string_piece.h"
26 #include "build/build_config.h"
32 class BASE_EXPORT CommandLine {
35 // The native command line string type.
36 using StringType = std::wstring;
37 #elif defined(OS_POSIX) || defined(OS_FUCHSIA)
38 using StringType = std::string;
41 using CharType = StringType::value_type;
42 using StringPieceType = base::BasicStringPiece<CharType>;
43 using StringVector = std::vector<StringType>;
44 using SwitchMap = std::map<std::string, StringType, std::less<>>;
46 // A constructor for CommandLines that only carry switches and arguments.
47 enum NoProgram { NO_PROGRAM };
48 explicit CommandLine(NoProgram no_program);
50 // Construct a new command line with |program| as argv[0].
51 explicit CommandLine(const FilePath& program);
53 // Construct a new command line from an argument list.
54 CommandLine(int argc, const CharType* const* argv);
55 explicit CommandLine(const StringVector& argv);
57 CommandLine(const CommandLine& other);
58 CommandLine& operator=(const CommandLine& other);
63 // By default this class will treat command-line arguments beginning with
64 // slashes as switches on Windows, but not other platforms.
66 // If this behavior is inappropriate for your application, you can call this
67 // function BEFORE initializing the current process' global command line
68 // object and the behavior will be the same as Posix systems (only hyphens
69 // begin switches, everything else will be an arg).
70 static void set_slash_is_not_a_switch();
72 // Normally when the CommandLine singleton is initialized it gets the command
73 // line via the GetCommandLineW API and then uses the shell32 API
74 // CommandLineToArgvW to parse the command line and convert it back to
75 // argc and argv. Tests who don't want this dependency on shell32 and need
76 // to honor the arguments passed in should use this function.
77 static void InitUsingArgvForTesting(int argc, const char* const* argv);
80 // Initialize the current process CommandLine singleton. On Windows, ignores
81 // its arguments (we instead parse GetCommandLineW() directly) because we
82 // don't trust the CRT's parsing of the command line, but it still must be
83 // called to set up the command line. Returns false if initialization has
84 // already occurred, and true otherwise. Only the caller receiving a 'true'
85 // return value should take responsibility for calling Reset.
86 static bool Init(int argc, const char* const* argv);
88 // Destroys the current process CommandLine singleton. This is necessary if
89 // you want to reset the base library to its initial state (for example, in an
90 // outer library that needs to be able to terminate, and be re-initialized).
91 // If Init is called only once, as in main(), Reset() is not necessary.
92 // Do not call this in tests. Use base::test::ScopedCommandLine instead.
95 // Get the singleton CommandLine representing the current process's
96 // command line. Note: returned value is mutable, but not thread safe;
97 // only mutate if you know what you're doing!
98 static CommandLine* ForCurrentProcess();
100 // Returns true if the CommandLine has been initialized for the given process.
101 static bool InitializedForCurrentProcess();
104 static CommandLine FromString(StringPieceType command_line);
107 // Initialize from an argv vector.
108 void InitFromArgv(int argc, const CharType* const* argv);
109 void InitFromArgv(const StringVector& argv);
111 // Constructs and returns the represented command line string.
112 // CAUTION! This should be avoided on POSIX because quoting behavior is
114 // CAUTION! If writing a command line to the Windows registry, use
115 // GetCommandLineStringForShell() instead.
116 StringType GetCommandLineString() const;
119 // Returns the command-line string in the proper format for the Windows shell,
120 // ending with the argument placeholder "--single-argument %1". The single-
121 // argument switch prevents unexpected parsing of arguments from other
122 // software that cannot be trusted to escape double quotes when substituting
123 // into a placeholder (e.g., "%1" insert sequences populated by the Windows
125 // NOTE: this must be used to generate the command-line string for the shell
126 // even if this command line was parsed from a string with the proper syntax,
127 // because the --single-argument switch is not preserved during parsing.
128 StringType GetCommandLineStringForShell() const;
130 // Returns the represented command-line string. Allows the use of unsafe
131 // Windows insert sequences like "%1". Only use this method if
132 // GetCommandLineStringForShell() is not adequate AND the processor inserting
133 // the arguments is known to do so securely (i.e., is not the Windows shell).
134 // If in doubt, do not use.
135 StringType GetCommandLineStringWithUnsafeInsertSequences() const;
138 // Constructs and returns the represented arguments string.
139 // CAUTION! This should be avoided on POSIX because quoting behavior is
141 StringType GetArgumentsString() const;
143 // Returns the original command line string as a vector of strings.
144 const StringVector& argv() const { return argv_; }
146 // Get and Set the program part of the command line string (the first item).
147 FilePath GetProgram() const;
148 void SetProgram(const FilePath& program);
150 // Returns true if this command line contains the given switch.
151 // Switch names must be lowercase.
152 // The second override provides an optimized version to avoid inlining codegen
153 // at every callsite to find the length of the constant and construct a
155 bool HasSwitch(StringPiece switch_string) const;
156 bool HasSwitch(const char switch_constant[]) const;
158 // Returns the value associated with the given switch. If the switch has no
159 // value or isn't present, this method returns the empty string.
160 // Switch names must be lowercase.
161 std::string GetSwitchValueASCII(StringPiece switch_string) const;
162 FilePath GetSwitchValuePath(StringPiece switch_string) const;
163 StringType GetSwitchValueNative(StringPiece switch_string) const;
165 // Get a copy of all switches, along with their values.
166 const SwitchMap& GetSwitches() const { return switches_; }
168 // Append a switch [with optional value] to the command line.
169 // Note: Switches will precede arguments regardless of appending order.
170 void AppendSwitch(StringPiece switch_string);
171 void AppendSwitchPath(StringPiece switch_string, const FilePath& path);
172 void AppendSwitchNative(StringPiece switch_string, StringPieceType value);
173 void AppendSwitchASCII(StringPiece switch_string, StringPiece value);
175 // Removes the switch that matches |switch_key_without_prefix|, regardless of
176 // prefix and value. If no such switch is present, this has no effect.
177 void RemoveSwitch(const base::StringPiece switch_key_without_prefix);
179 // Copy a set of switches (and any values) from another command line.
180 // Commonly used when launching a subprocess.
181 void CopySwitchesFrom(const CommandLine& source,
182 const char* const switches[],
185 // Get the remaining arguments to the command.
186 StringVector GetArgs() const;
188 // Append an argument to the command line. Note that the argument is quoted
189 // properly such that it is interpreted as one argument to the target command.
190 // AppendArg is primarily for ASCII; non-ASCII input is interpreted as UTF-8.
191 // Note: Switches will precede arguments regardless of appending order.
192 void AppendArg(StringPiece value);
193 void AppendArgPath(const FilePath& value);
194 void AppendArgNative(StringPieceType value);
196 // Append the switches and arguments from another command line to this one.
197 // If |include_program| is true, include |other|'s program as well.
198 void AppendArguments(const CommandLine& other, bool include_program);
200 // Insert a command before the current command.
201 // Common for debuggers, like "gdb --args".
202 void PrependWrapper(StringPieceType wrapper);
205 // Initialize by parsing the given command line string.
206 // The program name is assumed to be the first item in the string.
207 void ParseFromString(StringPieceType command_line);
211 // Disallow default constructor; a program name must be explicitly specified.
212 CommandLine() = delete;
213 // Allow the copy constructor. A common pattern is to copy of the current
214 // process's command line and then add some flags to it. For example:
215 // CommandLine cl(*CommandLine::ForCurrentProcess());
216 // cl.AppendSwitch(...);
218 // Append switches and arguments, keeping switches before arguments.
219 void AppendSwitchesAndArguments(const StringVector& argv);
221 // Internal version of GetArgumentsString to support allowing unsafe insert
222 // sequences in rare cases (see
223 // GetCommandLineStringWithUnsafeInsertSequences).
224 StringType GetArgumentsStringInternal(
225 bool allow_unsafe_insert_sequences) const;
228 // Initializes by parsing |raw_command_line_string_|, treating everything
229 // after |single_arg_switch_string| + <a single character> as the command
230 // line's single argument, and dropping any arguments previously parsed. The
231 // command line must contain |single_arg_switch_string|, and the argument, if
232 // present, must be separated from |single_arg_switch_string| by one
234 // NOTE: the single-argument switch is not preserved after parsing;
235 // GetCommandLineStringForShell() must be used to reproduce the original
236 // command-line string with single-argument switch.
237 void ParseAsSingleArgument(const StringType& single_arg_switch_string);
239 // The string returned by GetCommandLineW(), to be parsed via
240 // ParseFromString(). Empty if this command line was not parsed from a string,
241 // or if ParseFromString() has finished executing.
242 StringPieceType raw_command_line_string_;
245 // The singleton CommandLine representing the current process's command line.
246 static CommandLine* current_process_commandline_;
248 // The argv array: { program, [(--|-|/)switch[=value]]*, [--], [argument]* }
251 // Parsed-out switch keys and values.
254 // The index after the program and switches, any arguments start here.
260 #endif // BASE_COMMAND_LINE_H_