Thread: looping a switch statement with argc as cases

Is it possible to build a loop around a switch statement using argc as cases b/c I want to have differing command line args.
e.g. [convert_dec_to_bin] [target] [print] or [convert_dec_to_bin] [target] [check_status] [shift]

so the above are the command lines args in argv: argv[0], argv[1] etc. b/c I want to build a simple base-10 to base-2 conversion program and as long as user doesn't want to quit, they can re-enter new command line args. I know it works w/ using prompt, but if I didn't want that (such as cin, getline), is it possible? Somehow I think not b/c we need to re execute the exe(convert_dec_to_bin.exe)...not sure

e.g.

Code:

while ( input != 'q' )
{
   switch (argc )
      case 2: 
            //do this
      case 3:
          //do this
}

Yes, it is possible.

I'm not sure exactly how. This is what I have:
So the functions I wrote are:
1)print_bits_ : converts base-10 to binary
2) is_on : to test if a single bit in target val is on or not
3) turn_on : turn on the bit
4) turn_off : " " off " "

Code:

void dec_to_bin(int argc, char** argv)
{
    string menu
    (
        "Radix-10 to Binary converter v1.0 by monkey_c_monkey\n"
        "=========================================\n"
        "How to use: (NB: all inputs are optional)\n"
            "low [target] [check status] [change bit in target] [print target in binary]\n"
        "[TARGET]\n"
            "e.g. 2 (any unsigned integer) or '_' if you want to use previous target\n"
        "[CHECK STATUS]\n"
            "[target] [s] [which bit to shift to for the mask]\n"
        "[CHANGE BIT IN TARGET]\n"
            "[1] turn on bit: [target] [o] [which bit]\n"
            "[2] turn off bit: [target] [f] [which bit]\n"
        "[PRINT]\n"
            "[target] [p]\n"
        "[HELP]\n"
            "prints instructions to use program: [h]\n"
    );
    
    //the inputs to program
    unsigned int target;
    char option = ' ';
    unsigned int shift = 0;    
    unsigned int your_target = 0;//in case user forgets to enter it

    target = atoi(argv[1]);
    option = *argv[2];
    shift = atoi(argv[3]);
            
    if ( target != '_' )//we want to continue using the initial target input user entered
            your_target = target;
    else 
        your_target = your_target;//keep as is
    
    switch (argc)
    {    
        case 3://[exe] [t]/[_] [p]/[h]
            if ( option == 'h' )
                cout << menu << endl;
            else if ( option == 'p' )
                print_bits_(your_target);
            else if ( option == 's' )
                is_on(your_target, shift);
            else if ( option == 'o' )
                turn_on(your_target, shift);
            else if ( option == 'f' )
                turn_off(your_target, shift);
            break;
        case 4://[exe] [t]/[_] [s]/[o]/[f] [shift]
            if ( option == 's' )
                is_on(your_target, shift);
            else if ( option == 'o' )
                turn_on(your_target, shift);
            else if ( option == 'f' )
                turn_off(your_target, shift);
            break;
    }
}

int main(int argc, char* argv[])
{
   char input = 'n';
   string continue = "Do you want to run program again (y\n)?";
   if ( argc > 1 )
   {
     do
     {
        dec_to_bin(argc, argv);
        cout << continue << endl;      
     }
      while ( input == 'y' );
   }
  return 0;
}

EDIT: it doesn't crash anymore since I just forgot to check condition to make sure:

Code:

if ( argc > 1 )

and all functions work fine, but it exits, so how can I get chance to choose input of 'y' to continue?

So when I run first time in cmd.exe (I'm using Windows...):
============================================
C:\Users\joey\Desktop\cpp_workspace>conver_dec_to_ bin 2 p
0000 0000 0000 0000 0000 0000 0000 0010
Do you want to run program again (y/n)?

C:\Users\joey\Desktop\cpp_workspace>

*program exits, so I don't have chance to answer the prompt: "Do you want to run program etc....?"

I have to say that you're on the right track but a switch case for argc needs to have a default case.

I might decide to do something like
low 123456 o 4 p h

And you will have to decide what to do about it.

edit: I also don't think looping is a good idea. You have to rerun the program to get new arguments.