};
+/**
+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:
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;
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:
virtual void store(const std::string &) = 0;
};
-private:
template<typename T>
- 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() { }
GetOpt();
~GetOpt();
+ /// Returns any non-option arguments encountered during processing.
const std::vector<std::string> &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<typename T>
- OptBase &add_option(char s, const std::string &l, T &d, ArgType a = NO_ARG)
- { opts.push_back(new Option<T>(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<T>(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<typename T>
- OptBase &add_option(char s, const std::string &l, std::list<T> &d, ArgType a = REQUIRED_ARG)
- { opts.push_back(new ListOption<std::list<T> >(s, l, d, a)); return *opts.back(); }
-
+ Option &add_option(char s, const std::string &l, std::list<T> &d, ArgType a = REQUIRED_ARG)
+ { return add_option(new ListOption<std::list<T> >(s, l, d, a)); }
+
+ /** Adds an option with only a long form. */
template<typename T>
- 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 &);
std::string generate_help() const;
};
-template<> inline void GetOpt::Option<bool>::store() { data = true; }
-template<> inline void GetOpt::Option<unsigned>::store() { ++data; }
+template<> inline void GetOpt::SimpleOption<bool>::store()
+{ data = true; }
+
+template<> inline void GetOpt::SimpleOption<unsigned>::store()
+{ ++data; }
-template<> inline void GetOpt::Option<std::string>::store(const std::string &a)
+template<> inline void GetOpt::SimpleOption<std::string>::store(const std::string &a)
{ data = a; }
template<> inline void GetOpt::ListOption<std::list<std::string> >::store(const std::string &a)
projects / libs / core.git / blobdiff