Detect a palindrome

Main thing to remember for this question is the ctype.h function toupper, isspace, and isalpha. I only used one of them here – but it will save white board space in an interview situation.

int StringPalindromeDetect(char *testStr){
  int tail = 0;
  int head;

  if( testStr == (char *)NULL)
    return(FALSE);

  head = (strlen(testStr)-1);

  while(tail < head){
    // Wind tail forward.
    if((testStr[tail] == ' ')||(testStr[tail] == '\'')||(testStr[tail] == ',')){
      tail++;
      continue;
    }

    // Wind head backwards.
    if((testStr[head] == ' ')||(testStr[head] == '\'')||(testStr[head] == ',')){
      head--;
      continue;
    }

    if(toupper(testStr[tail])  != toupper(testStr[head]))
      return(FALSE);

    tail++;
    head--;
  }

  return(TRUE);
}


int main(){
  char *testStr = "Don't nod";
  printf("\nString to test is: %s\n", testStr);

  if( StringPalindromeDetect( testStr ) == TRUE ){
    printf("\nString is a palindrome.\n\n");
  }else{
    printf("\nString is not a palindrome.\n\n");
  }

  return(0);
}