Question

Possible Duplicate:
How do I iterate over a range of numbers in bash?

I am trying to print “Hello World!” 10 times via the code below, but it is printed only one time. Where am I missing the correct syntax?

RUNS=10

for RUN in {1..$RUNS}
do
    echo "Hello World!"
done

Answer 1

You want to do a brace expansion, but bash does not do double-expansion (it needs to expand $RUNS). You can force double-expansion by

for RUN in $(eval echo {1..$RUNS})
do 
    echo "Hello World!"
done

But I suggest you avoid this mess like the plague and just do

for RUN in $(seq 1 $RUNS) 
do 
    echo "Hello World!"
done

or

for ((RUN=1; RUN<RUNS; RUN++))
do 
    echo "Hello World!"
done