Thread: How do I make a char switch case?

I'm making "Basic OS", but it really starts from DOS, XD oh well anyway...

I want it to get your input after the ">>> ", right now I want to start off starting the 'exit' command, how do I make a switch that checks a char varaable, if theres a better way to do this plz post a reply.

Code:

#include <stdio.h>
#include <stdlib.h>

#define TURE 1
#define FALSE 0

int _END=0;

int main(int argc, char *argv[])
{
  char name_login[5000];
  char command[500];
  
  printf("\n\n\tWelcome To BOS the Basic Oparateing System\n\n\nPlz Type in your name: ");
  scanf("%s", name_login);
  
  printf("\n\nHello %s", name_login);
  
  if(_END!=1)
  {
    printf("\n>>> ");
    scanf("&s", command);
    switch command
    {
        case1(command="exit") = {return 0;}
    
    }
     
  }else{}
  scanf("%s", command);
}

THX

You can't. switch requires an int.

Originally posted by XSquared
You can't. switch requires an int.

Actually, a single char would work in a switch statement. However, strings will not. They could get close:

Code:

switch( tolower( command[0] ) )
{
    case 'e':
        if( strcmp( command, "exit" ) == 0 )
        {
        }
        else
        if( strcmp( command, "extra" ) == 0 )
        {
        }
    break;
    case 'l':
        if( strcmp( command, "lalala" ) == 0 )
        {
        }
    break;
    /* and so on */
}

But again, to clarify, it requires an integral data type. This means no floating point numbers, no strings, no structures. Only things that can be considered 'int' in type.

Quzah.

Use strcmp when comparing strings, not = (or as it should be, ==).

There are quite a few threads on here that show basic code for a shell. Try searching around a bit and see what you find.

heres the code now:

Code:

#include <stdio.h>
#include <stdlib.h>

#define TURE 1
#define FALSE 0

int _END=0;

int main(int argc, char *argv[])
{
  char name_login[5000];
  char command[500];
  
  printf("\n\n\tWelcome To BOS the Basic Oparateing System\n\n\nPlz Type in your name: ");
  scanf("%s", name_login);
  
  printf("\n\nHello %s", name_login);
  
  if(_END!=1)
  {
    printf("\n>>> ");
    scanf("&s", command);
    switch( tolower( command[0] ) ){
      case 'e': 
      {
          if( strcmp( command, "exit" ) == 0 )
          {
              printf("exiting");
          }
          
          _END=1;
          break;
      }
      
      default: {printf("unknown command");break;}
    }
   }

  return 0;
}

but now the output is this:

Code:

        Welcome To BOS the Basic Oparateing System


Plz Type in your name: Karl


Hello Karl
>>> unknown command

wat do I need to fix and how?

Also, look up flushing the input buffer.

>>_END
Variable names starting with an underscore followed by an uppercase letter are reserved, so you shouldn't be using them. I suggest to change it to END, loosing the underscore.

what about taking advantage of argv by reading in the user name from the command prompt?

Is this meant to run more than once? if so, use a loop and not an if