Chapter 4: Shell Scripting

Activity 10: PGN Game Extractor Enhancement

The solutions are provided in five script files, pgn_extract_act1.sh to pgn_extract_act5.sh. Each script contains the changes made in the previous problem steps, so pgn_extract_act5.sh has all the issues that were mentioned previously addressed. The following are the possible solutions:

1. The following code can work:

   function count_moves()
   {
     IFS='.'
     local moves_arr=( $moves )
     local second_last=${moves_arr[@]: -2 : 1}
     IFS=' '
     local second_last_arr=( $second_last )
   
     num_moves=${second_last_arr[@]: -1 : 1}
   }

2. Detecting blank lines can be done by testing for an empty string, such as the following:

   [[ -z $line ]] && return 0

3. Instead of expressions such as count=$(( count + 1 )), we can write (( count ++ )). We can also change the [[ ]] based conditionals, which test numeric variables such as [[ $should_print...