https://en.wikipedia.org/wiki/Fibonacci_number

The Fibonacci sequence implemented in various languages:

• C
• C++
• Bash
• Haskell

$ ./run 
make: Nothing to be done for 'all'.
Fibonacci 45 is 1134903170

real	0m15.086s
user	0m15.084s
sys	0m0.000s
fibonacci_cpp.o	pass

real	0m18.053s
user	0m18.016s
sys	0m0.020s
fibonacci.o	pass

real	0m0.096s
user	0m0.000s
sys	0m0.000s
fibonacci.sh	fail

real	0m0.162s
user	0m0.128s
sys	0m0.028s
fibonacci.hs	fail