def input_keywords(scf_in):
  """Extract all keywords from a quantum espresso input file

  Args:
    scf_in (str): path to input file
  Return:
    dict: a dictionary of inputs
  """
  keywords = dict()
  with open(scf_in, 'r') as f:
    for line in f:
      if '=' in line:
        key, val = line.split('=')
        keywords[key.strip()] = val.strip('\n')
  return keywords