for{}convariable.txt

#!/bin/bash
START=1
END=5
echo "Countdown"
 
for (( c=$START; c<=$END; c++ ))
do
	echo -n "$c "
	sleep 1
done
 
echo
echo "Boom!"

# No funciona for i in {0..$a}

#Otra solucion

#!/bin/bash
START=1
END=5
for i in $(eval echo "{$START..$END}")
do
	echo "$i"
done