///////    FIle objopt.C    ///////
#include <iostream.h>
#include <stdlib.h>

class Option
{   public:
      Option();
      // extract options from argc and argv
      void extract(int &argc, char *argv[]); 

      // option flags
      int objfile_only;   // produce .o files only, = 0
      char* ofile_name;   // output filename = "a.out"
      int unknown_option; // error flag = 0
      /* ... */
};

Option::Option()
{   objfile_only = 0;
    ofile_name = "a.out";
    unknown_option = 0;
}

void Option::extract(int &argc, char *argv[])
{   char *token = argv[1];
    int arg_cnt = 0;                              // true args count
    // go through each command-line arg 
    for (int i = 1 ; i < argc ; token = argv[++i])
    { if ( token[0] == '-')                       // if token an option
        for(int k = 1 ; token[k] != '\0' ; k++)   // option processing
        {  switch (token[k])
           {  case 'c':
		 objfile_only = 1; break;         // turn on flag
              case 'o':
		 if ( i < argc - 1 )
		     ofile_name = argv[++i];      // output filename
                 break;
              /*  ...  */
              default:
		 cerr << argv[0] << ": "
		      << token[k]  
                      << " unknown option\n";
                 unknown_option = 1;              // error flag
           } // end of switch
        }
      else   // token not an option
        argv[++arg_cnt] = token;                  // coalescing other args
    }        // end of outer for
    argc = arg_cnt + 1;                           // modified argc
    argv[argc] = NULL;                            // end marker
}
Option g_opt;   // global option object

int main(int argc, char *argv[])
{   cout << g_opt.ofile_name << "\n";
    g_opt.extract(argc, argv);
    if ( g_opt.unknown_option ) exit(1);
    for (int i=0; i < argc; i++)
       cout << argv[i] << " "; 
    cout << "\n";
    cout << g_opt.ofile_name << "\n";
}