-/* $Id$
-
-This file is part of libmspcore
-Copyright © 2006-2007 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
#ifndef MSP_CORE_GETOPT_H_
#define MSP_CORE_GETOPT_H_
-#include <sstream>
+#include <list>
+#include <stdexcept>
#include <string>
#include <vector>
-#include "except.h"
+#include <msp/strings/lexicalcast.h>
namespace Msp {
+class usage_error: public std::runtime_error
+{
+private:
+ std::string help_;
+
+public:
+ usage_error(const std::string &w, const std::string &h = std::string()): std::runtime_error(w), help_(h) { }
+ ~usage_error() throw() { }
+
+ const char *help() const throw() { return help_.c_str(); }
+};
+
+
+/**
+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:
- OptBase &set_help(const std::string &h) { help=h; return *this; }
- 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; }
- unsigned get_seen_count() const { return seen_count; }
- virtual void process()=0;
- virtual void process(const std::string &)=0;
- virtual ~OptBase() { }
+ 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;
+ char shrt;
std::string lng;
- ArgType arg_type;
- unsigned seen_count;
+ ArgType arg_type;
+ unsigned seen_count;
+ unsigned *ext_seen_count;
std::string help;
+ std::string metavar;
- OptBase(char s, const std::string &l, ArgType a): shrt(s), lng(l), arg_type(a), seen_count(0) { }
+ OptBase(char, const std::string &, ArgType);
+ public:
+ virtual ~OptBase() { }
+
+ 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; }
+ virtual unsigned get_seen_count() const { return seen_count; }
+ void process();
+ void process(const std::string &);
+ protected:
+ virtual void store() = 0;
+ 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 process()
- {
- if(arg_type==REQUIRED_ARG)
- throw UsageError("--"+lng+" requires an argument");
- process_();
- ++seen_count;
- }
+ virtual void store() { }
- virtual void process(const std::string &a)
+ virtual void store(const std::string &a)
{
- if(arg_type==NO_ARG)
- throw UsageError("--"+lng+" takes no argument");
-
- T tmp;
- std::istringstream ss(a);
- ss>>tmp;
- if(ss.fail())
- throw UsageError("Invalid argument for --"+lng);
-
- data=tmp;
- ++seen_count;
+ try
+ {
+ data = lexical_cast<T>(a);
+ }
+ catch(const lexical_error &e)
+ {
+ throw usage_error("Invalid argument for --"+lng+" ("+e.what()+")");
+ }
}
- private:
- T &data;
-
- void process_() { }
};
template<typename T>
class ListOption: public OptBase
{
+ private:
+ T &data;
+
public:
ListOption(char s, const std::string &l, T &d, ArgType a): OptBase(s, l, a), data(d)
- { if(arg_type!=REQUIRED_ARG) throw Exception("ListOption with arg_type!=REQUIRED makes no sense"); }
+ { if(arg_type!=REQUIRED_ARG) throw std::invalid_argument("ListOption arg_type!=REQUIRED"); }
- virtual void process()
- {
- throw UsageError("--"+lng+" requires an argument");
- }
+ virtual void store() { }
- virtual void process(const std::string &a)
+ virtual void store(const std::string &a)
{
- typename T::value_type tmp;
- std::istringstream ss(a);
- ss>>tmp;
- if(ss.fail())
- throw UsageError("Invalid argument for --"+lng);
-
- data.push_back(tmp);
- ++seen_count;
+ try
+ {
+ data.push_back(lexical_cast<typename T::value_type>(a));
+ }
+ catch(const lexical_error &e)
+ {
+ throw usage_error("Invalid argument for --"+lng+" ("+e.what()+")");
+ }
}
- private:
- T &data;
};
+ bool help;
std::list<OptBase *> opts;
std::vector<std::string> args;
public:
+ 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); }
- std::string generate_usage(const std::string &) const;
- std::string generate_help() const;
- void operator()(unsigned, const char *const *);
private:
+ OptBase &add_option(OptBase *);
OptBase &get_option(char);
OptBase &get_option(const std::string &);
+
+public:
+ /** Processes argc/argv style command line arguments. The contents of argv
+ will be unchanged; use get_args to access non-option arguments. */
+ void operator()(unsigned, const char *const *);
+
+private:
+ /** Processes a long option. Returns the number of arguments eaten. */
unsigned process_long(const char *const *);
+
+ /** Processes short options. Returns the number of arguments eaten. */
unsigned process_short(const char *const *);
+
+public:
+ /** Generates a single line that describes known options. */
+ std::string generate_usage(const std::string &) const;
+
+ /** Generates help for known options in tabular format, one option per
+ line. The returned string will have a linefeed at the end. */
+ std::string generate_help() const;
};
-template<> inline void GetOpt::Option<bool>::process_() { data=true; }
-template<> inline void GetOpt::Option<unsigned>::process_() { ++data; }
+template<> inline void GetOpt::SimpleOption<bool>::store()
+{ data = true; }
+
+template<> inline void GetOpt::SimpleOption<unsigned>::store()
+{ ++data; }
+
+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)
+{ data.push_back(a); }
} // namespace Msp
projects / libs / core.git / blobdiff