Parse passed arguments from shell.

def _parse(args):
    """Parse passed arguments from shell."""

    ordered = []
    opt_full = dict()
    opt_abbrev = dict()

    args = args + ['']  # Avoid out of range
    i = 0

    while i < len(args) - 1:
        arg = args[i]
        arg_next = args[i+1]
        if arg.startswith('--'):
            if arg_next.startswith('-'):
                raise ValueError('{} lacks value'.format(arg))
            else:
                opt_full[arg[2:]] = arg_next
                i += 2
        elif arg.startswith('-'):
            if arg_next.startswith('-'):
                raise ValueError('{} lacks value'.format(arg))
            else:
                opt_abbrev[arg[1:]] = arg_next
                i += 2
        else:
            ordered.append(arg)
            i += 1
    
    return ordered, opt_full, opt_abbrev