fibvalid.sh

#!/bin/bash

# usage:
#        ./fibvalid.sh numberOfFib actualNumber
# example:
#        ./fibvalid.sh 10 55
#        ok, fib(10) = 55
#        ./fibvalid.sh 10 54
#        fail, fib(10) = 55, not 54

set -euo pipefail

EXPECT="$(curl -s http://www.protocol5.com/Fibonacci/$1.htm | grep -oP 'Decimal\s+Base\s+10.*<div>\K\d+')"

if [[ -z "$EXPECT" ]]; then
    echo "fail to fetch fibonacci number from http://www.protocol5.com/Fibonacci/$1.htm"
    exit 2;
fi

if [[ "$EXPECT" != "$2" ]]; then
    echo "fail, fib($1) = $EXPECT, not $2"
    exit 1;
fi
echo "ok, fib($1) = $EXPECT"
exit 0;