cmdline.cpp

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/*
 * cmdline.cpp
 *
 * Copyright 2004  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Implementation of command line parsing object.
 */

// includes --------------------------------------------------------------------
#include "cmdline.h"            // always include our own header first!


// CommandLine interface destructor implementation
CommandLine::~CommandLine(void) throw() { }


////////////////////////////////////////////////////////////////////////////////
//
//      Implementation class
//
////////////////////////////////////////////////////////////////////////////////

class CmdImpl : public CommandLine {
public:
        // constructor, destructor ---------------------------------------------
        ~CmdImpl(void) throw() { }

        // public class methods ------------------------------------------------
        void initialize(IN int argc, IN const char * argv[]) throw();

        // CommandLine class interface methods ---------------------------------
        virtual void getKeys(OUT VecString& keys) throw();
        virtual bool getValues(IN const char * key,
                                OUT VecString& values) throw();

private:
        // private typedefs ----------------------------------------------------
        typedef std::map<std::string, VecString> KeyValues;

        // private data members ------------------------------------------------
        KeyValues       m_values;
};



////////////////////////////////////////////////////////////////////////////////
//
//      CmdImpl - public class methods
//
////////////////////////////////////////////////////////////////////////////////

void
CmdImpl::initialize
(
IN int argc,
IN const char * argv[]
)
throw()
{
        ASSERT(argc > 0, "No arguments at all?");

        VecString * values = NULL;      // current values
        for (int i = 1; i < argc; ++i) {
                // look at this argument -- is it a key?
                const char * p = argv[i];
                if (strstr(p, "--") == p) {
                        // key!  strip leading dashes, and store
                        p += 2; // skip dashes
                        KeyValues::iterator x = m_values.find(p);
                        if (m_values.end() != x) {
                                ASSERT(false, "Parameter '--%s' is specified "
                                    "multiple times on the command line", p);
                        }
                        VecString empty;
                        m_values[p] = empty;
                        values = &m_values[p];
                        ASSERT(0 == values->size(), "Should be empty");
                } else {
                        // must be a value
                        if (!values) {
                                ASSERT(false, "Read value '%s' without a key?",
                                    p);
                        }
                        values->push_back(p);
                }
        }
}



////////////////////////////////////////////////////////////////////////////////
//
//      CmdImpl -- CommandLine class interface methods
//
////////////////////////////////////////////////////////////////////////////////

void
CmdImpl::getKeys
(
OUT VecString& keys
)
throw()
{
        keys.clear();

        for (KeyValues::iterator i = m_values.begin(); i != m_values.end();
             ++i) {
                keys.push_back(i->first);
        }
}



bool
CmdImpl::getValues
(
IN const char * key,
OUT VecString& values
)
throw()
{
        ASSERT(key, "NULL key");

        values.clear();

        KeyValues::iterator i = m_values.find(key);
        if (m_values.end() == i) {
                // DPRINTF("No such key found on command line: %s", key);
                return false;
        }

        values = i->second;
        return true;
}



////////////////////////////////////////////////////////////////////////////////
//
//      CommandLine -- public static methods (factories)
//
////////////////////////////////////////////////////////////////////////////////

smart_ptr<CommandLine>
CommandLine::create
(
IN int argc,
IN const char * argv[]
)
throw()
{
        smart_ptr<CmdImpl> local = new CmdImpl;
        local->initialize(argc, argv);
        return local;
}



////////////////////////////////////////////////////////////////////////////////
//
//      public API + helpers
//
////////////////////////////////////////////////////////////////////////////////

const char *
getSingleKeyValue
(
IN CommandLine * cmd,
IN const char * key,
bool is_required,
const char * description
)
throw()
{
        ASSERT(cmd, "null");
        ASSERT(key, "null");
        IMPLIES(is_required, description, "must have description if required");

        VecString values;
        if (!cmd->getValues(key, values)) {
                if (!is_required)
                        return NULL;
                ASSERT(false, "Missing required command-line parameter '--%s' "
                    "(%s)", key, description);
        }

        ASSERT(1 == values.size(),
            "Parameter '--%s' can only have 1 value, you have %d",
            key, (int) values.size());
        return values[0].c_str();
}