php - (PHP) 解析命令

Question

我想获取命令标签(GET、FROM、IN 等)的值。我的命令是:

// My command
$_cmd = 'GET a, b FROM p IN a and c="I am from Sarajevo" or d>1 ';

// My parser
if(preg_match_all('/(GET|FROM|IN)\s+([^\s]+)/si',$_cmd, $m))
    $cmd = array_combine($m[1], $m[2]);

输出:

Array
(
  [GET] => a,
  [FROM] => p
  [IN] => a
  [from] => Sarajevo"
)

我正在寻找这个输出:

Array
(
  [GET] => a, b
  [FROM] => p
  [IN] => a and c="I am from Sarajevo" or d>1
)

如您所见，问题在于字符串中的空格 和重复命令标签(如from)。那么我该如何解析这个命令呢？

Answer 1

您无法使用单个正则表达式轻松解析它。 (这是可行的，但并不简单。)

您应该使用一个简单的分词器，其中正则表达式再次成为一个有用的工具:

  preg_match_all('/\w+|".*?"|\W/', $_cmd = 'GET a, b FROM p IN a and c="I am from Sarajevo" or d>1 ', $list);

这为您提供了一个简单的列表，您只需在其中找到您感兴趣的子句，然后重新合并后续标记(尽管我对您的用例感到困惑):

[0] => Array
    (
        [0] => GET
        [1] => a
        [2] => ,
        [3] => b
        [4] => FROM
        [5] => p
        [6] => IN
        [7] => a
        [8] => and
        [9] => c
        [10] => =
        [11] => "I am from Sarajevo"
        [12] => or
        [13] => d
        [14] => >
        [15] => 1
    )