I am tryingfor i in {4..100}do  is_prime=true  a=$(($i-1))  for divider in {2..$a}  do      b=$(($i % $divider)) # <-- line 9    [ $b -eq 0 ] && echo 'y' #is_prime=false  done  [ is_prime == true ] && print ${i} is prime!donebut I get $ ./3_largest_prime.sh ./3_largest_prime.sh: line 9: 4 % {2..3}: syntax error: operand expected(error token is {2..3})
bash shell - how to do nested loop without syntax error: operand expected
bash;scripting
If you put  set -xv  in your script, you might be able to detect why there is an error.In your script, it will output this line:+for divider in '{2..$a}'Notice the expansion did not occur. Read through the linked duplicates to identify how to fix it.