int reverse(char s[]){
  int i=0, i2=0, tmp='\0', tmp2=0;
  //how long is the string
  while(s[i2]!='\0'){
    i2++;
  }
  tmp2=i2; // remember length for later use
  
  //debugging
  printf("\nLine is %d long.\n", tmp2);
  
  while(i<=tmp2){
    tmp=s[i];
    s[i]=s[i2];
    s[i2]=tmp;
    i++;
    i2--;
  }
  //break - string should be reversed.
  return i;
}