// Copyright 2014 The ChromiumOS Authors // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // This class works with command lines: building and parsing. // Arguments with prefixes ('--', '-', and on Windows, '/') are switches. // Switches will precede all other arguments without switch prefixes. // Switches can optionally have values, delimited by '=', e.g., "-switch=value". // An argument of "--" will terminate switch parsing during initialization, // interpreting subsequent tokens as non-switch arguments, regardless of prefix. // There is a singleton read-only CommandLine that represents the command line // that the current process was started with. It must be initialized in main(). #ifndef GESTURES_COMMAND_LINE_H_ #define GESTURES_COMMAND_LINE_H_ #include #include #include #include namespace gestures { class CommandLine { public: typedef std::string::value_type CharType; typedef std::vector StringVector; typedef std::map SwitchMap; CommandLine(); ~CommandLine(); // Initialize the current process CommandLine singleton. On Windows, ignores // its arguments (we instead parse GetCommandLineW() directly) because we // don't trust the CRT's parsing of the command line, but it still must be // called to set up the command line. Returns false if initialization has // already occurred, and true otherwise. Only the caller receiving a 'true' // return value should take responsibility for calling Reset. static bool Init(int argc, const char* const* argv); // Destroys the current process CommandLine singleton. This is necessary if // you want to reset the base library to its initial state (for example, in an // outer library that needs to be able to terminate, and be re-initialized). // If Init is called only once, as in main(), Reset() is not necessary. static void Reset(); // Get the singleton CommandLine representing the current process's // command line. Note: returned value is mutable, but not thread safe; // only mutate if you know what you're doing! static CommandLine* ForCurrentProcess(); // Initialize from an argv vector. void InitFromArgv(int argc, const CharType* const* argv); void InitFromArgv(const StringVector& argv); // Returns the original command line string as a vector of strings. const StringVector& argv() const { return argv_; } // Get and Set the program part of the command line string (the first item). std::string GetProgram() const; void SetProgram(const std::string& program); // Returns true if this command line contains the given switch. // (Switch names are case-insensitive). bool HasSwitch(const std::string& switch_string) const; // Returns the value associated with the given switch. If the switch has no // value or isn't present, this method returns the empty string. std::string GetSwitchValueASCII(const std::string& switch_string) const; // Get a copy of all switches, along with their values. const SwitchMap& GetSwitches() const { return switches_; } // Append a switch [with optional value] to the command line. // Note: Switches will precede arguments regardless of appending order. void AppendSwitch(const std::string& switch_string); void AppendSwitchASCII(const std::string& switch_string, const std::string& value); // Get the remaining arguments to the command. StringVector GetArgs() const; // Append an argument to the command line. Note that the argument is quoted // properly such that it is interpreted as one argument to the target command. // AppendArg is primarily for ASCII; non-ASCII input is interpreted as UTF-8. // Note: Switches will precede arguments regardless of appending order. void AppendArgASCII(const std::string& value); private: // Allow the copy constructor. A common pattern is to copy of the current // process's command line and then add some flags to it. For example: // CommandLine cl(*CommandLine::ForCurrentProcess()); // cl.AppendSwitch(...); // The singleton CommandLine representing the current process's command line. static CommandLine* current_process_commandline_; // The argv array: { program, [(--|-|/)switch[=value]]*, [--], [argument]* } StringVector argv_; // Parsed-out switch keys and values. SwitchMap switches_; // The index after the program and switches, any arguments start here. size_t begin_args_; }; } // namespace gestures #endif // GESTURES_COMMAND_LINE_H_