Question

我有以下XML片段：

...

<Setting name="HOST1">server1</Setting>
<Setting name="HOST2">server2</Setting>
<Setting name="HOST3">server4</Setting>
<Setting name="HOST4">server8n12</Setting>
...
<!-- Many more such declarations all with the attribute of the form "HOSTNN" -->

我使用LibXML查找与HOST匹配的节点

my $dom = XML::LibXML->load_xml(location => $xml)
    or die "Unable to create LibXML object";
my $root = $dom->getDocumentElement();

my @hostnames = $root->findnodes('//Setting[contains(@name,"HOST")]');

是否可以在XPath表达式中指定一类字符，类似于在regexp中指定的字符？例如，Perl正则表达式：

/^HOST\d+?$/

Answer 1

//Setting[starts-with(@name,"HOST")]
         [translate(substring-after(@name,"HOST"),
                    "0123456789",
                    "")=""]

编辑：我没有看到限定符。以上内容将与Setting[@name="HOST"]匹配。更严格：

//Setting[starts-with(@name,"HOST")]
         [number(substring-after(@name,"HOST")) = 
          substring-after(@name,"HOST")]

编辑2 ：上面的内容不够严格（它会匹配“HOST2.1”）。遗憾。

//Setting[starts-with(@name,"HOST")]
         [substring-after(@name,"HOST")]
         [translate(substring-after(@name,"HOST"),
                    "0123456789",
                    "")=""]

Answer 2

我的xpath有点生疏，但我认为这可能有用（或者我将css与xpath结合起来）

Setting[@name^="HOST"]

XPath：如何匹配属性中的一类字符？

2 个答案: