You can use the trap builtin to handle a user pressing ctrl-c during the execution of a Bash script. e.g. if you need to perform some cleanup functions.
#!/bin/bash
# trap ctrl-c and call ctrl_c()
trap ctrl_c INT
function ctrl_c() {
echo "** Trapped CTRL-C"
}
for i in `seq 1 5`; do
sleep 1
echo -n "."
done