1// Copyright (c) 2011 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// Switches can optionally have a value attached using an equals sign, as in
7// "-switch=value". Arguments that aren't prefixed with a switch prefix are
8// saved as extra arguments. An argument of "--" will terminate switch parsing,
9// causing everything after to be considered as extra arguments.
10
11// There is a singleton read-only CommandLine that represents the command line
12// that the current process was started with.  It must be initialized in main().
13
14#ifndef BASE_COMMAND_LINE_H_
15#define BASE_COMMAND_LINE_H_
16#pragma once
17
18#include <stddef.h>
19#include <map>
20#include <string>
21#include <vector>
22
23#include "base/base_api.h"
24#include "build/build_config.h"
25
26class FilePath;
27
28class BASE_API CommandLine {
29 public:
30#if defined(OS_WIN)
31  // The native command line string type.
32  typedef std::wstring StringType;
33#elif defined(OS_POSIX)
34  typedef std::string StringType;
35#endif
36
37  typedef std::vector<StringType> StringVector;
38  // The type of map for parsed-out switch key and values.
39  typedef std::map<std::string, StringType> SwitchMap;
40
41  // A constructor for CommandLines that only carry switches and arguments.
42  enum NoProgram { NO_PROGRAM };
43  explicit CommandLine(NoProgram no_program);
44
45  // Construct a new command line with |program| as argv[0].
46  explicit CommandLine(const FilePath& program);
47
48#if defined(OS_POSIX)
49  CommandLine(int argc, const char* const* argv);
50  explicit CommandLine(const StringVector& argv);
51#endif
52
53  ~CommandLine();
54
55  // Initialize the current process CommandLine singleton. On Windows, ignores
56  // its arguments (we instead parse GetCommandLineW() directly) because we
57  // don't trust the CRT's parsing of the command line, but it still must be
58  // called to set up the command line.
59  static void Init(int argc, const char* const* argv);
60
61  // Destroys the current process CommandLine singleton. This is necessary if
62  // you want to reset the base library to its initial state (for example, in an
63  // outer library that needs to be able to terminate, and be re-initialized).
64  // If Init is called only once, as in main(), Reset() is not necessary.
65  static void Reset();
66
67  // Get the singleton CommandLine representing the current process's
68  // command line. Note: returned value is mutable, but not thread safe;
69  // only mutate if you know what you're doing!
70  static CommandLine* ForCurrentProcess();
71
72#if defined(OS_WIN)
73  static CommandLine FromString(const std::wstring& command_line);
74#endif
75
76#if defined(OS_POSIX)
77  // Initialize from an argv vector.
78  void InitFromArgv(int argc, const char* const* argv);
79  void InitFromArgv(const StringVector& argv);
80#endif
81
82  // Returns the represented command line string.
83  // CAUTION! This should be avoided because quoting behavior is unclear.
84  StringType command_line_string() const;
85
86#if defined(OS_POSIX)
87  // Returns the original command line string as a vector of strings.
88  const StringVector& argv() const { return argv_; }
89#endif
90
91  // Returns the program part of the command line string (the first item).
92  FilePath GetProgram() const;
93
94  // Returns true if this command line contains the given switch.
95  // (Switch names are case-insensitive).
96  bool HasSwitch(const std::string& switch_string) const;
97
98  // Returns the value associated with the given switch. If the switch has no
99  // value or isn't present, this method returns the empty string.
100  std::string GetSwitchValueASCII(const std::string& switch_string) const;
101  FilePath GetSwitchValuePath(const std::string& switch_string) const;
102  StringType GetSwitchValueNative(const std::string& switch_string) const;
103
104  // Get the number of switches in this process.
105  // TODO(msw): Remove unnecessary API.
106  size_t GetSwitchCount() const;
107
108  // Get a copy of all switches, along with their values.
109  const SwitchMap& GetSwitches() const { return switches_; }
110
111  // Append a switch [with optional value] to the command line.
112  // CAUTION! Appending a switch after the "--" switch terminator is futile!
113  void AppendSwitch(const std::string& switch_string);
114  void AppendSwitchPath(const std::string& switch_string, const FilePath& path);
115  void AppendSwitchNative(const std::string& switch_string,
116                          const StringType& value);
117  void AppendSwitchASCII(const std::string& switch_string,
118                         const std::string& value);
119  void AppendSwitches(const CommandLine& other);
120
121  // Copy a set of switches (and any values) from another command line.
122  // Commonly used when launching a subprocess.
123  void CopySwitchesFrom(const CommandLine& source, const char* const switches[],
124                        size_t count);
125
126  // Get the remaining arguments to the command.
127  const StringVector& args() const { return args_; }
128
129  // Append an argument to the command line. Note that the argument is quoted
130  // properly such that it is interpreted as one argument to the target command.
131  // AppendArg is primarily for ASCII; non-ASCII input is interpreted as UTF-8.
132  void AppendArg(const std::string& value);
133  void AppendArgPath(const FilePath& value);
134  void AppendArgNative(const StringType& value);
135  void AppendArgs(const CommandLine& other);
136
137  // Append the arguments from another command line to this one.
138  // If |include_program| is true, include |other|'s program as well.
139  void AppendArguments(const CommandLine& other,
140                       bool include_program);
141
142  // Insert a command before the current command.
143  // Common for debuggers, like "valgrind" or "gdb --args".
144  void PrependWrapper(const StringType& wrapper);
145
146#if defined(OS_WIN)
147  // Initialize by parsing the given command line string.
148  // The program name is assumed to be the first item in the string.
149  void ParseFromString(const std::wstring& command_line);
150#endif
151
152 private:
153  // Disallow public default construction; a program name must be specified.
154  CommandLine();
155
156  // The singleton CommandLine representing the current process's command line.
157  static CommandLine* current_process_commandline_;
158
159  // We store a platform-native version of the command line, used when building
160  // up a new command line to be executed. This ifdef delimits that code.
161#if defined(OS_WIN)
162  // The quoted, space-separated command line string.
163  StringType command_line_string_;
164  // The name of the program.
165  StringType program_;
166#elif defined(OS_POSIX)
167  // The argv array, with the program name in argv_[0].
168  StringVector argv_;
169#endif
170
171  // Parsed-out switch keys and values.
172  SwitchMap switches_;
173
174  // Non-switch command line arguments.
175  StringVector args_;
176
177  // Allow the copy constructor. A common pattern is to copy the current
178  // process's command line and then add some flags to it. For example:
179  //   CommandLine cl(*CommandLine::ForCurrentProcess());
180  //   cl.AppendSwitch(...);
181};
182
183#endif  // BASE_COMMAND_LINE_H_
184