X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=blobdiff_plain;f=source%2Fcore%2Fgetopt.h;h=2aaceef836730aa24a966c3cfaa20bb9864e23a7;hp=56ab05123584ef83fcc51cd838802ef4a941c453;hb=9f8d6a18f68fb54b62e9f4a5cf1a1650282b3667;hpb=1f0843257065789231a9949e0a81b79afd7bbebe diff --git a/source/core/getopt.h b/source/core/getopt.h index 56ab051..2aaceef 100644 --- a/source/core/getopt.h +++ b/source/core/getopt.h @@ -22,6 +22,32 @@ public: }; +/** +Command line option processor. Both short and long options are supported, with +optional and required arguments. Automatic help text generation is also +available. + +Short options begin with a single dash and are identified by a single letter. +Multiple short options may be grouped if they take no arguments; for example, +the string "-abc" could be interpreted as having the options 'a', 'b' and 'c'. +If the option takes an argument and there are unused characters in the argv +element, then those characters are interpreted as the argument. Otherwise the +next element is taken as the argument. An optional argument must be given in +the same element. + +Long options begin with a double dash and are identified by an arbitrary +string. An argument can be specified either in the same argv element, +separated by an equals sign, or in the next element. As with short options, +an optional argument must be in the same element. + +A single option may have both alternative forms, but must always have at least +a long form. This is to encourage self-documenting options; it's much easier +to remember words than letters. + +A built-in --help option is provided and will output a list of options and +their associated help texts. An application may override this by providing +its own option with the same name. +*/ class GetOpt { public: @@ -31,14 +57,36 @@ public: OPTIONAL_ARG, REQUIRED_ARG }; - - class OptBase + + class Option + { + protected: + Option() { } + public: + virtual ~Option() { } + + /// Sets help text for the option. + virtual Option &set_help(const std::string &) = 0; + + /** Sets help text for the option, with a placeholder metavariable. The + metavariable is used to denote the argument in the option list. */ + virtual Option &set_help(const std::string &, const std::string &) = 0; + + virtual Option &bind_seen_count(unsigned &) = 0; + + /// Returns the number of times this option was seen on the command line. + virtual unsigned get_seen_count() const = 0; + }; + +private: + class OptBase: public Option { protected: char shrt; std::string lng; ArgType arg_type; unsigned seen_count; + unsigned *ext_seen_count; std::string help; std::string metavar; @@ -46,14 +94,15 @@ public: public: virtual ~OptBase() { } - OptBase &set_help(const std::string &); - OptBase &set_help(const std::string &, const std::string &); + virtual OptBase &set_help(const std::string &); + virtual OptBase &set_help(const std::string &, const std::string &); + virtual OptBase &bind_seen_count(unsigned &); char get_short() const { return shrt; } const std::string &get_long() const { return lng; } ArgType get_arg_type() const { return arg_type; } const std::string &get_help() const { return help; } const std::string &get_metavar() const { return metavar; } - unsigned get_seen_count() const { return seen_count; } + virtual unsigned get_seen_count() const { return seen_count; } void process(); void process(const std::string &); protected: @@ -61,15 +110,14 @@ public: virtual void store(const std::string &) = 0; }; -private: template - class Option: public OptBase + class SimpleOption: public OptBase { private: T &data; public: - Option(char s, const std::string &l, T &d, ArgType a): OptBase(s, l, a), data(d) { } + SimpleOption(char s, const std::string &l, T &d, ArgType a): OptBase(s, l, a), data(d) { } virtual void store() { } @@ -119,21 +167,33 @@ public: GetOpt(); ~GetOpt(); + /// Returns any non-option arguments encountered during processing. const std::vector &get_args() const { return args; } + /** Adds an option with both short and long forms. Processing depends on + the type of the destination variable and whether an argument is taken or + not. With an argument, the value is lexical_cast to appropriate type and + stored in the destination. Without an argument, a bool will be set to true + and an unsigned will be incremented; any other type will be ignored. */ template - OptBase &add_option(char s, const std::string &l, T &d, ArgType a = NO_ARG) - { opts.push_back(new Option(s, l, d, a)); return *opts.back(); } - + Option &add_option(char s, const std::string &l, T &d, ArgType a = NO_ARG) + { return add_option(new SimpleOption(s, l, d, a)); } + + /** Adds an option with both short and long forms. The option may be + specified multiple times, and the argument from each occurrence is stored in + the list. The argument type must be REQUIRED_ARG. */ template - OptBase &add_option(char s, const std::string &l, std::list &d, ArgType a = REQUIRED_ARG) - { opts.push_back(new ListOption >(s, l, d, a)); return *opts.back(); } - + Option &add_option(char s, const std::string &l, std::list &d, ArgType a = REQUIRED_ARG) + { return add_option(new ListOption >(s, l, d, a)); } + + /** Adds an option with only a long form. */ template - OptBase &add_option(const std::string &l, T &d, ArgType a) + Option &add_option(const std::string &l, T &d, ArgType a) { return add_option(0, l, d, a); } private: + OptBase &add_option(OptBase *); + OptBase &get_option(char); OptBase &get_option(const std::string &); @@ -158,10 +218,13 @@ public: std::string generate_help() const; }; -template<> inline void GetOpt::Option::store() { data = true; } -template<> inline void GetOpt::Option::store() { ++data; } +template<> inline void GetOpt::SimpleOption::store() +{ data = true; } + +template<> inline void GetOpt::SimpleOption::store() +{ ++data; } -template<> inline void GetOpt::Option::store(const std::string &a) +template<> inline void GetOpt::SimpleOption::store(const std::string &a) { data = a; } template<> inline void GetOpt::ListOption >::store(const std::string &a)