1 #ifndef MSP_CORE_GETOPT_H_
2 #define MSP_CORE_GETOPT_H_
8 #include <msp/strings/lexicalcast.h>
12 class usage_error: public std::runtime_error
18 usage_error(const std::string &w, const std::string &h = std::string()): std::runtime_error(w), help_(h) { }
19 ~usage_error() throw() { }
21 const char *help() const throw() { return help_.c_str(); }
26 Command line option processor. Both short and long options are supported, with
27 optional and required arguments. Automatic help text generation is also
30 Short options begin with a single dash and are identified by a single letter.
31 Multiple short options may be grouped if they take no arguments; for example,
32 the string "-abc" could be interpreted as having the options 'a', 'b' and 'c'.
33 If the option takes an argument and there are unused characters in the argv
34 element, then those characters are interpreted as the argument. Otherwise the
35 next element is taken as the argument. An optional argument must be given in
38 Long options begin with a double dash and are identified by an arbitrary
39 string. An argument can be specified either in the same argv element,
40 separated by an equals sign, or in the next element. As with short options,
41 an optional argument must be in the same element.
43 A single option may have both alternative forms, but must always have at least
44 a long form. This is to encourage self-documenting options; it's much easier
45 to remember words than letters.
47 A built-in --help option is provided and will output a list of options and
48 their associated help texts. An application may override this by providing
49 its own option with the same name.
68 /// Sets help text for the option.
69 virtual Option &set_help(const std::string &) = 0;
71 /** Sets help text for the option, with a placeholder metavariable. The
72 metavariable is used to denote the argument in the option list. */
73 virtual Option &set_help(const std::string &, const std::string &) = 0;
75 virtual Option &bind_seen_count(unsigned &) = 0;
77 /// Returns the number of times this option was seen on the command line.
78 virtual unsigned get_seen_count() const = 0;
89 virtual Store *clone() const = 0;
91 virtual bool is_list() const = 0;
92 virtual void store() = 0;
93 virtual void store(const std::string &) = 0;
96 class OptionImpl: public Option
103 unsigned *ext_seen_count;
109 OptionImpl(char, const std::string &, const Store &, ArgType);
110 virtual ~OptionImpl();
112 virtual OptionImpl &set_help(const std::string &);
113 virtual OptionImpl &set_help(const std::string &, const std::string &);
114 virtual OptionImpl &bind_seen_count(unsigned &);
115 char get_short() const { return shrt; }
116 const std::string &get_long() const { return lng; }
117 ArgType get_arg_type() const { return arg_type; }
118 const std::string &get_help() const { return help; }
119 const std::string &get_metavar() const { return metavar; }
120 virtual unsigned get_seen_count() const { return seen_count; }
122 void process(const std::string &);
126 class SimpleStore: public Store
132 SimpleStore(T &d): data(d) { }
134 virtual SimpleStore *clone() const
135 { return new SimpleStore(data); }
137 virtual bool is_list() const { return false; }
139 virtual void store() { }
141 virtual void store(const std::string &a)
142 { data = lexical_cast<T>(a); }
146 class ListStore: public Store
152 ListStore(T &d): data(d) { }
154 virtual ListStore *clone() const
155 { return new ListStore(data); }
157 virtual bool is_list() const { return true; }
159 virtual void store() { }
161 virtual void store(const std::string &a)
162 { data.push_back(lexical_cast<typename T::value_type>(a)); }
165 typedef std::list<OptionImpl *> OptionList;
169 std::vector<std::string> args;
175 /// Returns any non-option arguments encountered during processing.
176 const std::vector<std::string> &get_args() const { return args; }
178 /** Adds an option with both short and long forms. Processing depends on
179 the type of the destination variable and whether an argument is taken or
180 not. With an argument, the value is lexical_cast to appropriate type and
181 stored in the destination. Without an argument, a bool will be set to true
182 and an unsigned will be incremented; any other type will be ignored. */
184 Option &add_option(char s, const std::string &l, T &d, ArgType a = NO_ARG)
185 { return add_option(s, l, SimpleStore<T>(d), a); }
187 /** Adds an option with both short and long forms. The option may be
188 specified multiple times, and the argument from each occurrence is stored in
189 the list. The argument type must be REQUIRED_ARG. */
191 Option &add_option(char s, const std::string &l, std::list<T> &d, ArgType a = REQUIRED_ARG)
192 { return add_option(s, l, ListStore<std::list<T> >(d), a); }
194 /** Adds an option with only a long form. */
196 Option &add_option(const std::string &l, T &d, ArgType a)
197 { return add_option(0, l, d, a); }
200 OptionImpl &add_option(char, const std::string &, const Store &, ArgType);
202 OptionImpl &get_option(char);
203 OptionImpl &get_option(const std::string &);
206 /** Processes argc/argv style command line arguments. The contents of argv
207 will be unchanged; use get_args to access non-option arguments. */
208 void operator()(unsigned, const char *const *);
211 /** Processes a long option. Returns the number of arguments eaten. */
212 unsigned process_long(const char *const *);
214 /** Processes short options. Returns the number of arguments eaten. */
215 unsigned process_short(const char *const *);
218 /** Generates a single line that describes known options. */
219 std::string generate_usage(const std::string &) const;
221 /** Generates help for known options in tabular format, one option per
222 line. The returned string will have a linefeed at the end. */
223 std::string generate_help() const;
226 template<> inline void GetOpt::SimpleStore<bool>::store()
229 template<> inline void GetOpt::SimpleStore<unsigned>::store()
232 template<> inline void GetOpt::SimpleStore<std::string>::store(const std::string &a)
235 template<> inline void GetOpt::ListStore<std::list<std::string> >::store(const std::string &a)
236 { data.push_back(a); }