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 /// Returns the number of times this option was seen on the command line.
76 virtual unsigned get_seen_count() const = 0;
80 class OptBase: public Option
90 OptBase(char, const std::string &, ArgType);
92 virtual ~OptBase() { }
94 virtual OptBase &set_help(const std::string &);
95 virtual OptBase &set_help(const std::string &, const std::string &);
96 char get_short() const { return shrt; }
97 const std::string &get_long() const { return lng; }
98 ArgType get_arg_type() const { return arg_type; }
99 const std::string &get_help() const { return help; }
100 const std::string &get_metavar() const { return metavar; }
101 virtual unsigned get_seen_count() const { return seen_count; }
103 void process(const std::string &);
105 virtual void store() = 0;
106 virtual void store(const std::string &) = 0;
110 class SimpleOption: public OptBase
116 SimpleOption(char s, const std::string &l, T &d, ArgType a): OptBase(s, l, a), data(d) { }
118 virtual void store() { }
120 virtual void store(const std::string &a)
124 data = lexical_cast<T>(a);
126 catch(const lexical_error &e)
128 throw usage_error("Invalid argument for --"+lng+" ("+e.what()+")");
134 class ListOption: public OptBase
140 ListOption(char s, const std::string &l, T &d, ArgType a): OptBase(s, l, a), data(d)
141 { if(arg_type!=REQUIRED_ARG) throw std::invalid_argument("ListOption arg_type!=REQUIRED"); }
143 virtual void store() { }
145 virtual void store(const std::string &a)
149 data.push_back(lexical_cast<typename T::value_type>(a));
151 catch(const lexical_error &e)
153 throw usage_error("Invalid argument for --"+lng+" ("+e.what()+")");
159 std::list<OptBase *> opts;
160 std::vector<std::string> args;
166 /// Returns any non-option arguments encountered during processing.
167 const std::vector<std::string> &get_args() const { return args; }
169 /** Adds an option with both short and long forms. Processing depends on
170 the type of the destination variable and whether an argument is taken or
171 not. With an argument, the value is lexical_cast to appropriate type and
172 stored in the destination. Without an argument, a bool will be set to true
173 and an unsigned will be incremented; any other type will be ignored. */
175 Option &add_option(char s, const std::string &l, T &d, ArgType a = NO_ARG)
176 { return add_option(new SimpleOption<T>(s, l, d, a)); }
178 /** Adds an option with both short and long forms. The option may be
179 specified multiple times, and the argument from each occurrence is stored in
180 the list. The argument type must be REQUIRED_ARG. */
182 Option &add_option(char s, const std::string &l, std::list<T> &d, ArgType a = REQUIRED_ARG)
183 { return add_option(new ListOption<std::list<T> >(s, l, d, a)); }
185 /** Adds an option with only a long form. */
187 Option &add_option(const std::string &l, T &d, ArgType a)
188 { return add_option(0, l, d, a); }
191 OptBase &add_option(OptBase *);
193 OptBase &get_option(char);
194 OptBase &get_option(const std::string &);
197 /** Processes argc/argv style command line arguments. The contents of argv
198 will be unchanged; use get_args to access non-option arguments. */
199 void operator()(unsigned, const char *const *);
202 /** Processes a long option. Returns the number of arguments eaten. */
203 unsigned process_long(const char *const *);
205 /** Processes short options. Returns the number of arguments eaten. */
206 unsigned process_short(const char *const *);
209 /** Generates a single line that describes known options. */
210 std::string generate_usage(const std::string &) const;
212 /** Generates help for known options in tabular format, one option per
213 line. The returned string will have a linefeed at the end. */
214 std::string generate_help() const;
217 template<> inline void GetOpt::SimpleOption<bool>::store()
220 template<> inline void GetOpt::SimpleOption<unsigned>::store()
223 template<> inline void GetOpt::SimpleOption<std::string>::store(const std::string &a)
226 template<> inline void GetOpt::ListOption<std::list<std::string> >::store(const std::string &a)
227 { data.push_back(a); }