source: trunk/lib/yat/CommandLine.h @ 983

#ifndef _theplu_yat_utility_commandline_
#define _theplu_yat_utility_commandline_

//$Id: CommandLine.h 2119 2009-12-12 23:11:43Z peter $

/*
  Copyright (C) 2007, 2008 Jari Häkkinen, Peter Johansson
  Copyright (C) 2009 Peter Johansson

  This file is part of the yat library, http://dev.thep.lu.se/yat

  The yat library is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 3 of the
  License, or (at your option) any later version.

  The yat library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include <cctype>
#include <map>
#include <iosfwd>
#include <sstream>
#include <stdexcept>
#include <string>
#include <typeinfo>
#include <utility>
#include <vector>

namespace theplu {
namespace yat {
namespace utility {

  class Option;

  /**
     @brief Class for parsing the command line.
     
     Provides parsing and storage of command line arguments. The class
     is typically used by hooking a number of Option objects to
     CommandLine, and then call the parse() function. Here is a short
     example how the class may be used:
  
     \code
  
     CommandLine cmd;
     OptionHelp help(cmd);
     OptionFile in(cmd, "i,in", 
                   "Read input from file (rather than standard input)",
                   false, true, "r");
     OptionFile out(cmd, "o,out", "Place the output to file", false, false, "w");
     OptionSwitch target(cmd, "T,target", "treat DEST as a normal file", true);
     OptionSwitch verbose(cmd, "v,verbose", "explain what is being done");
     OptionSwitch version(cmd, "version", "output version and exit");
     std::stringstream copyright;
     copyright << "example 1.0\n"
               << "Copyright (C) 2007 Peter Johansson\n\n"
               << "This is free software see the source for copying "
               << "conditions. There is NO\nwarranty; not even for "
               << "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n";
     try {
       cmd.parse(argc, argv);
     }
     catch (cmd_error& e){
       if (version.present()){
         std::cout << copyright.str();     
         return EXIT_SUCCESS;
       }
       std::cerr << e.what() << std::endl;
       return EXIT_FAILURE;
     }  
     if (version.present()){
       std::cout << copyright.str();     
       return EXIT_SUCCESS;
     }
     StreamRedirect sr_out(std::cout, out.value(), out.present());
     StreamRedirect sr_in(std::cin, in.value(), in.present());
     ...
     \endcode

     After creation a number of Option classes are hooked up to the
     CommandLine object in their constructors. 

     Each parameter is associated to a one-character flag and/or a
     longer string flag. The longer flag expects to be preceded by
     '--' as e.g. '--help' for help. The shorter flag expects to be
     preceded by '-' as e.g. '-h', and can also be concatenated like
     "program -vf", which is equivalent to "program -v -f". or
     its sibblings for different types.
  */
  class CommandLine
  {
  public:
    /**
       \brief default constructor

       \param str text preceeding the list of option in output
    */
    CommandLine(std::string str="Available options are:");

    /**
       \brief Destructor
    */
    virtual ~CommandLine(void);

    /**
       \brief Function to add an option. 
    */
    void add(Option&);

    /**
       \brief Allow at most \a n free arguments.

       An free argument is an argument not associated with an Option,
       allowing commandlines such as \code prog foo bar \endcode
     */
    void allow_free_args(size_t n);

    /**
       \brief Arguments not associated with an Option

       \see allow_free_args(size_t n)
    */
    const std::vector<std::string>& free_args(void) const;

    /**
       \brief parse the commandline

       First the commandline is parsed to detect which options are
       present, then each Option parses the its relevant part of
       commandline (Option::parse()), and finally each Option is
       validated (Option::validate()).

       throw cmd_error if an error is detected.
    */
    void parse(int argc, char* argv[]);

    /**
       \brief has the commandline been parsed already

       \return true if parse function has already been called

       \since New in yat 0.5
    */
    bool parsed(void) const;

    /**
       @return Name of more; more specifically argv[0] is
       stripped so only string after the last '/' remains.
     */
    std::string program_name(void) const;

    /**
       \return something like "Try `<program_name()> --help` for
       more information."
     */
    std::string try_help(void) const;

  private:
    friend std::ostream& operator<<(std::ostream& os, const CommandLine& cl);
    void add_private(std::string, Option&);
    bool is_long_option(std::string str) const;
    bool is_short_option(std::string str) const;
    std::vector<std::string> split(std::string str, char del) const;

    std::string description_;
    std::vector<std::string> free_arg_;
    size_t free_arg_max_;
    std::vector<Option*> options_;
    std::map<char, Option*> short_options_;
    std::map<std::string, Option*> long_options_;
    bool parsed_;
    std::string program_name_;
  };

  /**
     \brief CommandLine output operator

     A typical output may look like this
     \verbatim
     Available options are:
     -h, --help      display this help and exit
     -v, --verbose   explain what is being done
     \endverbatim
     The output starts with a descriptive line such as "Available
     options are:" (default) that can be set in constructor. Then follows the
     options described in the order they were added to
     Commandline. Each Option is described according to
     Option::print(void) function.
     \see OptionHelp

     \relates CommandLine
  */
  std::ostream& operator<<(std::ostream&, const CommandLine&);

}}} // end of namespace utility, yat, and theplu

#endif