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// 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// An argument of "--" will terminate switch parsing during initialization,
10// interpreting subsequent tokens as non-switch arguments, regardless of prefix.
11
12// There is a singleton read-only CommandLine that represents the command line
13// that the current process was started with.  It must be initialized in main().
14
15#ifndef BASE_COMMAND_LINE_H_
16#define BASE_COMMAND_LINE_H_
17
18#include <stddef.h>
19#include <map>
20#include <string>
21#include <vector>
22
23#include "base/base_export.h"
24#include "build/build_config.h"
25
26namespace base {
27
28class FilePath;
29
30class BASE_EXPORT CommandLine {
31 public:
32#if defined(OS_WIN)
33  // The native command line string type.
34  typedef std::wstring StringType;
35#elif defined(OS_POSIX)
36  typedef std::string StringType;
37#endif
38
39  typedef StringType::value_type CharType;
40  typedef std::vector<StringType> StringVector;
41  typedef std::map<std::string, StringType> SwitchMap;
42
43  // A constructor for CommandLines that only carry switches and arguments.
44  enum NoProgram { NO_PROGRAM };
45  explicit CommandLine(NoProgram no_program);
46
47  // Construct a new command line with |program| as argv[0].
48  explicit CommandLine(const FilePath& program);
49
50  // Construct a new command line from an argument list.
51  CommandLine(int argc, const CharType* const* argv);
52  explicit CommandLine(const StringVector& argv);
53
54  ~CommandLine();
55
56#if defined(OS_WIN)
57  // By default this class will treat command-line arguments beginning with
58  // slashes as switches on Windows, but not other platforms.
59  //
60  // If this behavior is inappropriate for your application, you can call this
61  // function BEFORE initializing the current process' global command line
62  // object and the behavior will be the same as Posix systems (only hyphens
63  // begin switches, everything else will be an arg).
64  static void set_slash_is_not_a_switch();
65#endif
66
67  // Initialize the current process CommandLine singleton. On Windows, ignores
68  // its arguments (we instead parse GetCommandLineW() directly) because we
69  // don't trust the CRT's parsing of the command line, but it still must be
70  // called to set up the command line. Returns false if initialization has
71  // already occurred, and true otherwise. Only the caller receiving a 'true'
72  // return value should take responsibility for calling Reset.
73  static bool Init(int argc, const char* const* argv);
74
75  // Destroys the current process CommandLine singleton. This is necessary if
76  // you want to reset the base library to its initial state (for example, in an
77  // outer library that needs to be able to terminate, and be re-initialized).
78  // If Init is called only once, as in main(), Reset() is not necessary.
79  static void Reset();
80
81  // Get the singleton CommandLine representing the current process's
82  // command line. Note: returned value is mutable, but not thread safe;
83  // only mutate if you know what you're doing!
84  static CommandLine* ForCurrentProcess();
85
86  // Returns true if the CommandLine has been initialized for the given process.
87  static bool InitializedForCurrentProcess();
88
89#if defined(OS_WIN)
90  static CommandLine FromString(const std::wstring& command_line);
91#endif
92
93  // Initialize from an argv vector.
94  void InitFromArgv(int argc, const CharType* const* argv);
95  void InitFromArgv(const StringVector& argv);
96
97  // Constructs and returns the represented command line string.
98  // CAUTION! This should be avoided on POSIX because quoting behavior is
99  // unclear.
100  StringType GetCommandLineString() const;
101
102  // Constructs and returns the represented arguments string.
103  // CAUTION! This should be avoided on POSIX because quoting behavior is
104  // unclear.
105  StringType GetArgumentsString() const;
106
107  // Returns the original command line string as a vector of strings.
108  const StringVector& argv() const { return argv_; }
109
110  // Get and Set the program part of the command line string (the first item).
111  FilePath GetProgram() const;
112  void SetProgram(const FilePath& program);
113
114  // Returns true if this command line contains the given switch.
115  // (Switch names are case-insensitive).
116  bool HasSwitch(const std::string& switch_string) const;
117
118  // Returns the value associated with the given switch. If the switch has no
119  // value or isn't present, this method returns the empty string.
120  std::string GetSwitchValueASCII(const std::string& switch_string) const;
121  FilePath GetSwitchValuePath(const std::string& switch_string) const;
122  StringType GetSwitchValueNative(const std::string& switch_string) const;
123
124  // Get a copy of all switches, along with their values.
125  const SwitchMap& GetSwitches() const { return switches_; }
126
127  // Append a switch [with optional value] to the command line.
128  // Note: Switches will precede arguments regardless of appending order.
129  void AppendSwitch(const std::string& switch_string);
130  void AppendSwitchPath(const std::string& switch_string,
131                        const FilePath& path);
132  void AppendSwitchNative(const std::string& switch_string,
133                          const StringType& value);
134  void AppendSwitchASCII(const std::string& switch_string,
135                         const std::string& value);
136
137  // Copy a set of switches (and any values) from another command line.
138  // Commonly used when launching a subprocess.
139  void CopySwitchesFrom(const CommandLine& source,
140                        const char* const switches[],
141                        size_t count);
142
143  // Get the remaining arguments to the command.
144  StringVector GetArgs() const;
145
146  // Append an argument to the command line. Note that the argument is quoted
147  // properly such that it is interpreted as one argument to the target command.
148  // AppendArg is primarily for ASCII; non-ASCII input is interpreted as UTF-8.
149  // Note: Switches will precede arguments regardless of appending order.
150  void AppendArg(const std::string& value);
151  void AppendArgPath(const FilePath& value);
152  void AppendArgNative(const StringType& value);
153
154  // Append the switches and arguments from another command line to this one.
155  // If |include_program| is true, include |other|'s program as well.
156  void AppendArguments(const CommandLine& other, bool include_program);
157
158  // Insert a command before the current command.
159  // Common for debuggers, like "valgrind" or "gdb --args".
160  void PrependWrapper(const StringType& wrapper);
161
162#if defined(OS_WIN)
163  // Initialize by parsing the given command line string.
164  // The program name is assumed to be the first item in the string.
165  void ParseFromString(const std::wstring& command_line);
166#endif
167
168 private:
169  // Disallow default constructor; a program name must be explicitly specified.
170  CommandLine();
171  // Allow the copy constructor. A common pattern is to copy of the current
172  // process's command line and then add some flags to it. For example:
173  //   CommandLine cl(*CommandLine::ForCurrentProcess());
174  //   cl.AppendSwitch(...);
175
176  // The singleton CommandLine representing the current process's command line.
177  static CommandLine* current_process_commandline_;
178
179  // The argv array: { program, [(--|-|/)switch[=value]]*, [--], [argument]* }
180  StringVector argv_;
181
182  // Parsed-out switch keys and values.
183  SwitchMap switches_;
184
185  // The index after the program and switches, any arguments start here.
186  size_t begin_args_;
187};
188
189}  // namespace base
190
191// TODO(brettw) remove once all callers specify the namespace properly.
192using base::CommandLine;
193
194#endif  // BASE_COMMAND_LINE_H_
195