CommandLineParser.hpp

#pragma once
//-----------------------------------------------------------------------------
// Class:   CommandLineParser
// Authors: LiXizhi
// Emails:  LiXizhi@yeah.net
// Company: ParaEngine Co.
// Date:    2010.4.25
// Desc: Header only helper class. It can be used for applications who do not link with the core ParaEngine plugin. 
//-----------------------------------------------------------------------------
#include <string>
#include <map>

namespace ParaEngine
{
    class CCommandLineParser
    {
    public:
        CCommandLineParser(const char* lpCmdLine = NULL)
        {
            SetCommandLine(lpCmdLine);
        }


        const char* GetCommandLine()
        {
            return m_sAppCmdLine.c_str();
        }

        const char* GetValue(const char* pParam, const char* defaultValue)
        {
            std::map<string, string>::iterator it =  m_commandParams.find(pParam);
            if(it!= m_commandParams.end())
            {
                return (*it).second.c_str();
            }
            if(defaultValue!=NULL)
            {
                m_commandParams[pParam] = defaultValue;
                return m_commandParams[pParam].c_str();
            }
            return NULL;
        }

        void SetCommandLine(const char* pCommandLine)
        {
            if(pCommandLine)
                m_sAppCmdLine = pCommandLine;
            else
                m_sAppCmdLine.clear();


            int nPos = 0;
            int nBegin = 0;
            while((nPos =(int) m_sAppCmdLine.find('=', nBegin))!=string::npos)
            {
                int i = nPos-1; 
                int nFromPos = (int)m_sAppCmdLine.find('\"', nBegin+1);
                if(nFromPos!=(int)string::npos)
                {
                    int nToPos = (int)m_sAppCmdLine.find('\"', nFromPos+1);
                    if(nToPos!=(int)string::npos)
                    {
                        if(nPos>nBegin)
                        {
                            // remove heading and trailing spaces
                            for(;(m_sAppCmdLine[nBegin] == ' '|| m_sAppCmdLine[nBegin] == '\t' || m_sAppCmdLine[nBegin] == '\n' || m_sAppCmdLine[nBegin] == '\r'); nBegin++)
                                ;
                            for(;nPos>=1 && (m_sAppCmdLine[nPos-1] == ' '|| m_sAppCmdLine[nPos-1] == '\t' || m_sAppCmdLine[nPos-1] == '\n' || m_sAppCmdLine[nPos-1] == '\r'); nPos--)
                                ;
                            if(nPos>nBegin)
                            {
                                m_commandParams[m_sAppCmdLine.substr(nBegin, nPos-nBegin)] = m_sAppCmdLine.substr(nFromPos+1, nToPos - nFromPos-1);
                                nBegin = nToPos+1;
                                continue;
                            }
                        }
                    }
                }
                nBegin = nPos+1;
            }
        }

    private:
        std::string m_sAppCmdLine;

        std::map<std::string, std::string> m_commandParams;
    };
    
}