import os
import re
import shutil

def checkOutput(output):
    for line in output.split('\n'):
        if line == 'Hello world!': return True
    return False

def test_c():
    print(os.getcwd())
    fh = os.popen("./helloworld", mode='r', buffering=-1)
    output = fh.read()
    retcode = fh.close()
    assert retcode == None and checkOutput(output)