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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// 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".
// If a switch is specified multiple times, only the last value is used.
// 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().
#include <stddef.h>
#include <map>
#include <string>
#include <vector>
#include "base/base_export.h"
#include "base/strings/string_piece.h"
#include "build/build_config.h"
namespace base {
class FilePath;
class BASE_EXPORT CommandLine {
#if defined(OS_WIN)
// The native command line string type.
using StringType = std::wstring;
#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
using StringType = std::string;
using CharType = StringType::value_type;
using StringPieceType = base::BasicStringPiece<CharType>;
using StringVector = std::vector<StringType>;
using SwitchMap = std::map<std::string, StringType, std::less<>>;
// A constructor for CommandLines that only carry switches and arguments.
enum NoProgram { NO_PROGRAM };
explicit CommandLine(NoProgram no_program);
// Construct a new command line with |program| as argv[0].
explicit CommandLine(const FilePath& program);
// Construct a new command line from an argument list.
CommandLine(int argc, const CharType* const* argv);
explicit CommandLine(const StringVector& argv);
CommandLine(const CommandLine& other);
CommandLine& operator=(const CommandLine& other);
#if defined(OS_WIN)
// By default this class will treat command-line arguments beginning with
// slashes as switches on Windows, but not other platforms.
// If this behavior is inappropriate for your application, you can call this
// function BEFORE initializing the current process' global command line
// object and the behavior will be the same as Posix systems (only hyphens
// begin switches, everything else will be an arg).
static void set_slash_is_not_a_switch();
// Normally when the CommandLine singleton is initialized it gets the command
// line via the GetCommandLineW API and then uses the shell32 API
// CommandLineToArgvW to parse the command line and convert it back to
// argc and argv. Tests who don't want this dependency on shell32 and need
// to honor the arguments passed in should use this function.
static void InitUsingArgvForTesting(int argc, const char* const* argv);
// 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.
// Do not call this in tests. Use base::test::ScopedCommandLine instead.
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();
// Returns true if the CommandLine has been initialized for the given process.
static bool InitializedForCurrentProcess();
#if defined(OS_WIN)
static CommandLine FromString(StringPieceType command_line);
// Initialize from an argv vector.
void InitFromArgv(int argc, const CharType* const* argv);
void InitFromArgv(const StringVector& argv);
// Constructs and returns the represented command line string.
// CAUTION! This should be avoided on POSIX because quoting behavior is
// unclear.
// CAUTION! If writing a command line to the Windows registry, use
// GetCommandLineStringForShell() instead.
StringType GetCommandLineString() const;
#if defined(OS_WIN)
// Returns the command-line string in the proper format for the Windows shell,
// ending with the argument placeholder "--single-argument %1". The single-
// argument switch prevents unexpected parsing of arguments from other
// software that cannot be trusted to escape double quotes when substituting
// into a placeholder (e.g., "%1" insert sequences populated by the Windows
// shell).
// NOTE: this must be used to generate the command-line string for the shell
// even if this command line was parsed from a string with the proper syntax,
// because the --single-argument switch is not preserved during parsing.
StringType GetCommandLineStringForShell() const;
// Returns the represented command-line string. Allows the use of unsafe
// Windows insert sequences like "%1". Only use this method if
// GetCommandLineStringForShell() is not adequate AND the processor inserting
// the arguments is known to do so securely (i.e., is not the Windows shell).
// If in doubt, do not use.
StringType GetCommandLineStringWithUnsafeInsertSequences() const;
// Constructs and returns the represented arguments string.
// CAUTION! This should be avoided on POSIX because quoting behavior is
// unclear.
StringType GetArgumentsString() const;
// 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).
FilePath GetProgram() const;
void SetProgram(const FilePath& program);
// Returns true if this command line contains the given switch.
// Switch names must be lowercase.
// The second override provides an optimized version to avoid inlining codegen
// at every callsite to find the length of the constant and construct a
// StringPiece.
bool HasSwitch(const StringPiece& switch_string) const;
bool HasSwitch(const char switch_constant[]) 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.
// Switch names must be lowercase.
std::string GetSwitchValueASCII(const StringPiece& switch_string) const;
FilePath GetSwitchValuePath(const StringPiece& switch_string) const;
StringType GetSwitchValueNative(const StringPiece& 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 AppendSwitchPath(const std::string& switch_string,
const FilePath& path);
void AppendSwitchNative(const std::string& switch_string,
StringPieceType value);
void AppendSwitchASCII(const std::string& switch_string,
const std::string& value);
// Removes the switch that matches |switch_key_without_prefix|, regardless of
// prefix and value. If no such switch is present, this has no effect.
void RemoveSwitch(const base::StringPiece switch_key_without_prefix);
// Copy a set of switches (and any values) from another command line.
// Commonly used when launching a subprocess.
void CopySwitchesFrom(const CommandLine& source,
const char* const switches[],
size_t count);
// 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 AppendArg(const std::string& value);
void AppendArgPath(const FilePath& value);
void AppendArgNative(const StringType& value);
// Append the switches and arguments from another command line to this one.
// If |include_program| is true, include |other|'s program as well.
void AppendArguments(const CommandLine& other, bool include_program);
// Insert a command before the current command.
// Common for debuggers, like "gdb --args".
void PrependWrapper(const StringType& wrapper);
#if defined(OS_WIN)
// Initialize by parsing the given command line string.
// The program name is assumed to be the first item in the string.
void ParseFromString(StringPieceType command_line);
// Disallow default constructor; a program name must be explicitly specified.
CommandLine() = delete;
// 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(...);
// Append switches and arguments, keeping switches before arguments.
void AppendSwitchesAndArguments(const StringVector& argv);
// Internal version of GetArgumentsString to support allowing unsafe insert
// sequences in rare cases (see
// GetCommandLineStringWithUnsafeInsertSequences).
StringType GetArgumentsStringInternal(
bool allow_unsafe_insert_sequences) const;
#if defined(OS_WIN)
// Initializes by parsing |raw_command_line_string_|, treating everything
// after |single_arg_switch_string| + <a single character> as the command
// line's single argument, and dropping any arguments previously parsed. The
// command line must contain |single_arg_switch_string|, and the argument, if
// present, must be separated from |single_arg_switch_string| by one
// character.
// NOTE: the single-argument switch is not preserved after parsing;
// GetCommandLineStringForShell() must be used to reproduce the original
// command-line string with single-argument switch.
void ParseAsSingleArgument(const StringType& single_arg_switch_string);
// The string returned by GetCommandLineW(), to be parsed via
// ParseFromString(). Empty if this command line was not parsed from a string,
// or if ParseFromString() has finished executing.
StringPieceType raw_command_line_string_;
// 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 base