Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
# Rewrite this script using arrays, rather than indirect variable referencing.
# Which method is more straightforward and intuitive?
# Notes:
# −−−−−
# Shell scripts are inappropriate for anything except the most simple
#+ database applications, and even then it involves workarounds and kludges.
# Much better is to use a language with native support for data structures,
#+ such as C++ or Java (or even Perl).
exit 0
Example 35−4. Using arrays and other miscellaneous trickery to deal four random hands from a deck
of cards
#!/bin/bash
# May need to be invoked with #!/bin/bash2 on older machines.
# Cards:
# deals four random hands from a deck of cards.
UNPICKED=0
PICKED=1
DUPE_CARD=99
LOWER_LIMIT=0
UPPER_LIMIT=51
CARDS_IN_SUIT=13
CARDS=52
declare −a Deck
declare −a Suits
declare −a Cards
# It would have been easier and more intuitive
# with a single, 3−dimensional array.
# Perhaps a future version of Bash will support multidimensional arrays.
initialize_Deck ()
{
i=$LOWER_LIMIT
until [ "$i" −gt $UPPER_LIMIT ]
do
Deck[i]=$UNPICKED # Set each card of "Deck" as unpicked.
let "i += 1"
done
echo
}
initialize_Suits ()
{
Suits[0]=C #Clubs
Suits[1]=D #Diamonds
Suits[2]=H #Hearts
Suits[3]=S #Spades
}
initialize_Cards ()
Chapter 35. Bash, version 2 357