Incorrect use of “For Loop”

I am trying to limit the user to a max value of +/- 32768 when entering in a value into the program . To accomplish this I have to use a “For Loop” , my issue is I am not using the loop correctly and can not see why it’s not working in the program. Thank you for the help.

Code:

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#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
int times (int a, unsigned int b)
{
  int result;
  result=0;
  int shift;
 
  for(shift = 1; b != 0 && shift <= 32768;)              // Iterate the loop till b==0
  {
      if (shift,b&01)              // Logical ANDing of the value of b with 01
        result=result+a;  // Update the result with the new value of a.
      a<<=1;                // Left shifting the value contained in 'a' by 1.
      b>>=1;              // Right shifting the value contained in 'b' by 1.
  }
  return result;
}

const int TEXT_SIZE = 100;

int main ()
{
    printf("Hello, I'm a program that multplies integers. \n");
   
    do {
        int a;
        int b;
       
        char text[TEXT_SIZE];
       
        printf("Please enter the first integer or 'Q' to quit:  ");
        fgets(text,TEXT_SIZE,stdin);
       
        if  ( toupper(text[0])== 'Q')
                        break;
       
        a = atoi(text);
       
        printf ("Please enter the second intger or 'Q' to quit:  ");
        fgets(text,TEXT_SIZE,stdin);
       
      if  ( toupper(text[0])== 'Q')
                        break;
       
        b = atoi(text);
       
        printf("The product for %d and %d is %d.\n\n", a,b,times(a,b));
     
        }
        while (1);
        return(EXIT_SUCCESS);
        getch();
       
        }

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Why are you making this so complicated?

Ya, I know but it's a lesson using shifting and bitwise operations. I am new to the C language so it's making my life that much more rough. But I love the language , and really what to lean as much as I can ! ok, thanks if you do see my error !

Well, first a for loop is contructed with three parts like so:

for(x = 0; x < 100; ++ x)

in your loop it appears that the value of "shift" never changes and the break condition is really predicated on "b" being equal to zero. Therefore a while loop would be more appropriate:

while(b != 0)

To increment shift you should have

for(shift = 1; b != 0 && shift <= 32768; ++ shift)