Programozás
szerző: Szervác Attila
3. lecke
Ch3: Write your First Game


.3 Use random: Write 1st game


Let’s get a random number from the first character of a random string by the special \" character introducer of the printf.

sh -c 'c="a"; printf "%d\n" \""$c"' # ASCII code of the a character

Test #3 a

1: Write a random number sequence

2: Write a very simple passphrase generator

and be a true *h4ckeR* :)


Write your 1st game – prototype

szerkesztés

Write your first game!

Regards:
  • Generate a challenge for the player by using 2 or more random numbers and least one arithmetical operator
  • Create a fancy output :-) – also we can use it to web output in a CGI program if we know the basics of the SGML markup languages (for example the very minimal basics of the HTML language recommendations)
  • Store your upstream of your source code in a separated directory. The Upstream means: files of your source code.

The case pattern matching

szerkesztés

Finally in the programming we have various things to do for different character patterns. We can use the meta-characters (!*?[) to create our wishful character pattern as we have seen in the previous chapters. This is the case command. In short:

sh -c 'a="Love is in the air"; case $a in (*"s i"*) printf "1\n";; esac' # :)

Shorter:

sh -c 'a="asdf"; case $a in *d*) printf "1\n";; esac'

More complex example:

sh -c 'for a in ABDEF "I love abugida\!"; do case $a in *BC*|*BD*) printf "BC or BD\n";; *abugida*) printf "Not BC or BD but I Love \e[3mabugida!\e[0m :)\n"; esac; done'

:)

Test #3 b

1: Write a game that uses character pattern matching in this way.

2: Prepare a well-commented version of your program

Look into this short part of the latter 3-sort game (see the commented version of this game-proto in the appendix). How can it generate unique prng-sequences? Is it better to use ALL pseudo random numbers from the string? :-)

read -p "Type the max value up to 12 and press Enter: " n;
i=0; zps=""; while [ $i -le $n ]; do read s;
# c=`printf "%c" "$s"`; cc=`printf "%d" \""$c"`;
# v=`printf "%03o" "$((cc%(n+1)))"`;
# in the case above we are using all characters
# from the pseudo random string!! # :)
v=`printf "%03o" "$((${#s}%(n+1)))"`;
 if [ $i -le $n ]; then
 case $zps in *"$v "*) ;; *) zps="$zps$v "; i=$((i+1));; esac;
 fi;
done</dev/urandom; osca="";
for w in $zps; do
if [ $w != "000" ]; then d=`printf "%d" "$w"`; osca="$osca$d "
else osca="$osca. ";
fi;
i=$((i+1)); done;
printf "$osca\n";

3: See the all 3-sort – game-proto – program in the appendix. How can you sport it into a more gripping puzzle game? :))