gistfile1.txt

    while(s->string[i] != '\0') {
        newStringData[i] = s->string[i];
        i++;
    }
    //strcpy(newStringData, s->string);

    // copy over the null terminator + the checksum value
    for(int j=0;j<5;j++){
        newStringData[i+j] = s->string[i+j];
    }

// replace the above with

while(i < len + 5) { 
  newStringData[i] = s->string[i];
  i++;
  }