在C中读取具有未知格式的XML文件(Reading an XML file with an unkown format in C)

在C中读取具有未知格式的XML文件(Reading an XML file with an unkown format in C)

如何从具有未知格式的XML文件中读取，例如文件的格式可以是：

<data1>int1</data1> <data2>int2</data2> <data3>int3</data3> <data4>int4</data4>

要么

<data1>int1</data1> <data4>int4</data4>

要么

<data1>int1</data1> <data2>int2</data2> <data3>int3</data3> <data4>int4</data4> <data5>int5</data5>

在第二种情况下，我假设int2和int3将被分配默认值。 我想到了解决这个问题的一种方法，但它出现了凌乱和意大利面。 任何帮助，将不胜感激！

How do I read from an XML file with an unkown format, for example a file can be of the format:

<data1>int1</data1> <data2>int2</data2> <data3>int3</data3> <data4>int4</data4>

OR

<data1>int1</data1> <data4>int4</data4>

OR

<data1>int1</data1> <data2>int2</data2> <data3>int3</data3> <data4>int4</data4> <data5>int5</data5>

In the second case I am to assume int2 and int3 are to be assigned default values. I thought of one way to solve this problem but it came out messy and spaghetti like. Any help would be appreciated!

最满意答案

（1）这些都不是完整的XML文档。 需要有一个根元素。

（2）如果您不坚持限制其实例的数量和顺序，则很容易在DTD中声明元素内容可以是其他元素的混合，使用“|” 运营商。 （见http://www.w3.org/TR/xml11/#sec-element-content ）

（3）如果你想更严格地约束那些，那么是的，DTD可以要求拼写出所有的组合。 切换到针对XML Schema的验证是一个显而易见的解决方案; DTD几乎被认为是过时的，因为它们与XML命名空间（它已成为XML处理的基本部分）不兼容。

（4）如果你坚持坚持使用DTD，并且不能接受无约束的顺序/计数，并且不想拼出所有可能的顺序......考虑做一些检查和/或应用默认值您的应用程序代码而不是DTD。

(1) None of those is a complete XML document. There needs to be a single root element.

(2) If you don't insist on restricting the number and order of their of instances, it's easy to declare in a DTD that element content can be a mix of other elements, using the '|' operator. (See http://www.w3.org/TR/xml11/#sec-element-content)

(3) If you want to constrain those more tightly, then yes, DTDs can require spelling out all the combinations. Switching to validating against XML Schemas is one obvious solution; DTDs are pretty much considered obsolete anyway since they aren't compatible with XML Namespaces (which have become a basic part of XML processing).

(4) If you insist on sticking with DTDs, and can't accept unconstrained order/count, and don't want to spell out all the possible sequences... consider doing some of that checking and/or applying of default values in your application code rather than in the DTD.