Jeus Jimenez's questions

I am making a script that you put two numbers and it tells you if they are divisible. But it gives me an error. I am making a script that you put two numbers and it tells you if they are divisible. But it gives me an error. THE SCRIPT CODE:

#!/bin/bash



read -p "Numero 1: " num1

read -p "Numero 2: " num2

cero=0

$op=$(($num1%$num2))

if [$op -eq $cero] 

then

echo "ES DIVISIBLE"

else

echo "NO ES DIVISIBLE"

fi

/divisibles.sh

Numero 1: 4

Numero 2: 4

./divisibles.sh: línea 6: =0: orden no encontrada

./divisibles.sh: línea 7: [: falta un `]'

NO ES DIVISIBLE

In a .txt there are several DNIs, what I want to do is use the grep filter command to get the DNIs that have 9 numbers and 1 letter. I've tried this command but it doesn't work:

INSIDE THE FILE:

123456789A

31232g

42344324f

324f

4554345345345g

234452l

INSTRUCTION I HAVE USED:

cat nif.txt|grep -E "[[:digit:]]{9}[[:alpha:]]{1}"

123456789A

4554345345345g

I get the wrong ID and that's what I don't want it to do. Thanks in advance