#!/bin/bash

function main {
    echo "What fib should I calculate?"
    read n
    fib $n
    exit 0
}

hello () {
    echo "Hello"
}  # declaring the function hello

fib () {
    # $1 is the first arg, $2 second, etc. $0 is the function
    a=0
    b=1
    j=$1
    for i in $(seq 1 $j) 
    do
       c=$(expr "$a" + "$b")
       a=$b
       b=$c
       # echo "a $a b $b c $c"
    done
    echo "Fibb number $1 is $a"
}

main