How to use the case statement in a shell script, with case-insensitive input

Use the pipe (|) character for each possible case:

echo "TABLESPACE REPORT FOR $ORACLE_SID"

stty echo
   echo "All tablespaces or specific tablespace? [A|S]"
   read answer
stty echo

case $answer in
A|a) echo "All tablespaces selected...please wait...";
    getFiles A;;
S|s) echo "Which tablespace?";
    read wt;
    getFiles $wt;;
*) echo "Only A or S are supported parameters.";
    exit 1;;
esac