Recursive Fibonacci in Bash script

Question

This is my attempt:

#!/bin/bash

function fibonacci(){

first=$1
second=$2

if (( first <= second ))
then
return 1

else 

return $(fibonacci $((first-1))         


        

Answer 1

The $(...) substitution operator is replaced with the output of the command. Your function doesn't produce any output, so $(...) is the empty string.

Return values of a function go into $? just like exit codes of an external command.

So you need to either produce some output (make the function echo its result instead of returning it) or use $? after each call to get the value. I'd pick the echo.