CLI loops, including batch conversion of .xcf to .png

for I in {1..10}; do echo $I; done

for I in 1 2 3 4 5 6 7 8 9 10; do echo $I; done

for I in $(seq 1 10); do echo $I; done

for ((I=1; I <= 10 ; I++)); do echo $I; done


Apply to conversion of all .xcf files in a directory, to .png:

for i in `ls *.xcf`; do xcf2png $i -o $i.png; done