rename all files in a folder sequentially

rename_numerically.sh

#!/bin/bash
# batch rename all items in a folder regardless of title into sequential number order
# warning: will throw an error if you have any 

i=1
for f in *.jpg # remove .jpg if you want to force rename all files but be careful. Also: will throw error with directories
    do mv "$f" "$( printf "%02d.jpg" $i )" # the 02d means generate file numbers 00-99. use 3d for 000-999. 
    ((i++))
done