Check sha256 hash value

checksum

#!/usr/bin/env bash

FILE=$1
HASH=$2

[ -z "$FILE" ] && echo "Please provide valid file"

if [ -f "$FILE" ]; then
    FILESUM=$(shasum -a 256 $FILE | cut -f 1 -d ' ' | grep '[a-f0-9]')

    if [ -z "$HASH" ]; then
        echo $FILESUM
    else
        [[ $FILESUM == $HASH ]] && echo "Ok" || echo "Not Ok"
    fi
else
    echo "$FILE does not exist, Please provide valid file"
fi