import pyparsing, sys, doctest

pattern = pyparsing.Optional(pyparsing.CharsNotIn(';')) + ';'
pattern.ignore(pyparsing.sglQuotedString)
pattern.ignore(pyparsing.sglQuotedString)

redirect_pattern = pyparsing.Optional(pyparsing.CharsNotIn('<>')) + pyparsing.oneOf('< >') + pyparsing.Word(pyparsing.printables)
redirect_pattern.ignore(pyparsing.sglQuotedString)
redirect_pattern.ignore(pyparsing.sglQuotedString)

def parse(txt, mustBeTerminated=False):
    """
    >>> sorted(parse('select * from dual;', True).items())
    [('complete', True), ('inputFrom', None), ('outputTo', None), ('pipeTo', None)]
    >>> sorted(parse('select * from', True).items())
    [('complete', False), ('inputFrom', None), ('outputTo', None), ('pipeTo', None)]
    >>> sorted(parse('select * from dual; > result.txt', True).items())
    [('complete', True), ('inputFrom', None), ('outputTo', 'result.txt'), ('pipeTo', None)]
    """
    result = {'complete': not mustBeTerminated, 'inputFrom': None, 'outputTo': None, 'pipeTo': None}
    if mustBeTerminated:
        try:
            pattern.parseString(txt)
            result['complete'] = True
        except pyparsing.ParseException:
            pass
            
    if result['complete']:
        try:
            parsed = redirect_pattern.parseString(txt)
            if parsed[1] == '>':
                result['outputTo'] = parsed[2]
            else:
                result['inputFrom'] = parsed[2]
        except pyparsing.ParseException:
            pass
    return result
    
if __name__ == '__main__':
    doctest.testmod()