getopt_doc.h

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/* Copyright Benoit Hudson 2008 */
#ifndef getopt_doc_HEADER
#define getopt_doc_HEADER

#ifdef HAVE_CONFIG_H
 #include <config.h>
#endif

/***************************************************************************
 * A version of getopt that is less soul-sucking.
 *
 * Most important, it allows documenting the options.
 *
 * Usage:
 *
 * int main (int argc, char **argv) {
 *   OptionSet opts;
 *   bool bar = false;
 *   std::string cow = "Bessie";
 *   int bottles = 99;
 *   float cash = 0.0;
 *
 *   opts.addFlag("bar", true, "include bar", &bar);
 *   opts.addOption("cowname", "name", "name the cow", &cow);
 *   opts.addIntOption("bottles", "num", "number of bottles of beer on the wall", &bottles);
 *   opts.addFloatOption("cash", "$$.cc", "amount of cash in the register", &cash);
 *   opts.addSynonym("cowname", "c");
 *
 *   CommandLine cmds (opts, argc, argv);
 *   if (!cmds.process()) cmds.printUsage(1, "Says something silly.");
 *   printf("%s is %s counting the %d bottles on the wall.\n"
 *      , cow.c_str(), bar ? "at the bar" : "on a stool", bottles);
 * }
 *
 * ./a.out -c Marguerite --cash=50.23 --bottles=10 --bar=no
 * Marguerite is counting the 10 bottles on the wall.
 ***************************************************************************/

#include <string>
#include <vector>

namespace hudson {
  struct CommandLine;

  struct OptionSet {
    OptionSet();
    ~OptionSet();

    /* Add a flag with no arguments, like "-f" or "--flag". */

    void addFlag(
        const std::string& name,
        const std::string& description,
        bool *output);

    /* Add a flag with a string argument, like "--string=foo". */
    void addOption(
        const std::string& name,
        const std::string& variable_description,
        const std::string& description,
        std::string *output);

    /* Add a flag with an int argument, like "--answer=42". */
    void addIntOption(
        const std::string& name,
        const std::string& variable_description,
        const std::string& description,
        int *output);

    /* Add a flag with a floating-point argument, like "--delta=0.6". */
    void addFloatOption(
        const std::string& name,
        const std::string& variable_description,
        const std::string& description,
        double *output
        );

    /* Add a flag as a synonym for a previously-declared flag. */
    void addSynonym(
        const std::string& canonical,
        const std::string& alternate);

    /* Add a non-flag; just a spacer in the documentation.  
     * Don't include the newline; that's done here. */
    void addSpacer(const std::string& message);

    void print();

    private:
    friend struct CommandLine;
    struct guts;
    guts *guts_;
  };

  struct CommandLine {
    typedef std::vector<std::string> Arguments;

    CommandLine(const OptionSet&, int argc, const char * const *argv);
    CommandLine(const OptionSet&, const Arguments&);
    const Arguments& getArguments() const { return args; }

    bool hasNext() { return !done; }
    bool readNext();
    bool process() {
      bool ok = true;
      while(hasNext()) {
        bool success = readNext(); // always call readNext
        ok = success && ok; // don't merge these two lines
      }
      return ok;
    }

    unsigned index() { return current_index; }

    void printUsageAndExit(int exitval, const std::string& arguments,
        const std::string& description);

    private:
    void checkNext();
    bool interpret(const std::string& option);

    Arguments args;
    const OptionSet& opts;
    unsigned current_index;
    bool done;
  };
};



#endif

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