CODEWITHSUNDEEP
c
Nodnin
Nodnin

Reputation: 451

Stuck in a loop after switch in c

while (1)
{
    c = getchar();

    switch(state)
    {
      case 0:
          if((GPIO_ReadInputDataBit(GPIOA,GPIO_Pin_0) == Bit_SET))
          {
              state=1;
          }

          if ( c=='p')
          {
              state = 2;
          }
          break;

      case 1 :
          if((GPIO_ReadInputDataBit(GPIOA,GPIO_Pin_0) != Bit_SET))
          {
              state = 0;
          }
          break;

      case 2:
          iprintf("%s",led_name_arr[i]);
          if (c=='r')
          {
              state=0;
          }
          break;

    }
}

I want to print the printf and then reach state2 .. how can this be achieved .below is what i have tried and where i am stuck .

psuedocode:

if ( c==P)
{
  printf(" hi");
  state 2;
}

** in this case the printf statement does not get executed ** or 

case 2:
  iprintf("%s",led_name_arr[i]);
  if (c=='r')
  {
    state=0;
  }
  break;

** in this case the printf statement keeps printing in a loop **

i dont want the while loop to stop , in a continuous loop i want case 0 keeps working , but when it get the input p .. it pauses and executes the printf ... and waits till it gets a r to resume case 0 .... Thus the program never halts but waits to either get "P" or "R" to execute each case... I hope i make sense

Any help will be appreciated .

Upvotes: 1

Views: 813

Answers (5)

Puneet Purohit
Puneet Purohit

Reputation: 1281

Because you are not breaking the while(1) loop. Use one more break for while loop.

Upvotes: 0

George
George

Reputation: 171

i am not sure what you are asking but i m pretty sure what you want in case 2 is something like this:

case 2:
  iprintf("%s",led_name_arr[i]);
  while(c!='r')
  {
      c = getchar();
  }
  state=0;
  break;

Upvotes: 1

Gordon Bailey
Gordon Bailey

Reputation: 3911

Your breaks are breaking out of the switch ... case not the while. You'll need to use some kind of boolean flag to break out of the outer loop, e.g.:

bool someflag = true;
while(someflag){

   switch(something){
      case a:
         someflag = false; // set the flag so we break out of the loop
         break;            // break out of the switch-case so we don't enter case b
      case b:
         // do something else
         break;
   }
}

-------- EDIT, because I misunderstood the question ------------

I think you need an extra state in your logic, right now (ignoring state 1), you have two states:

  1. Wait for a p, when you get one, goto 2.

  2. printf for each character until you get an r, then goto 1

What you want is:

  1. Wait for a p, when you get one, goto 2.

  2. Do a printf, then goto 3.

  3. Wait for an r, when you get one, goto 1.

Upvotes: 3

resultsway
resultsway

Reputation: 13300

well, initialize state to 0

compile and run the program

first time enter p // here state =2

then enter r // here state = 0

....continue in a loop due to while(1)

Upvotes: 0

Carey Gregory
Carey Gregory

Reputation: 6846

You've created an infinite loop with the while (1) statement that has no possible exit. The break statements within the switch apply to the switch statement, not the while loop. You need another break statement outside the switch.

Upvotes: 1

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