如何使用xmllint和XPath从属性中获取值?

I want to get the value of name and put it in a variable using XMLLint

我想获取name的值，并使用XMLLint将其放入一个变量中

<body>
<value name="abc"></value>
</body>

echo 'cat //body/value/@name' | xmllint --shell "test.xml"

/ >  -------
 name="abc"
/ >

So I want to assign the value "abc" to variable $test

所以我想把“abc”的值赋给变量$test

4 个解决方案

#1

You need to use fn:string(), which will return the value of its argument as xs:string. In case its argument is an attribute, it will therefore return the attribute's value as xs:string.

您需要使用fn:string()，它将将其参数的值返回为xs:string。如果它的参数是一个属性，那么它将返回属性的值为xs:string。

test=$(xmllint --xpath "string(//body/value/@name)" test.xml)

#2

Try this, it's not beautiful but it works :)

试试这个，它不漂亮，但很管用:

I just erase lines containing > from stdout , cut the string to get the second part after the = , and delete "

我只是擦掉了从stdout中包含>的行，将字符串切成=，然后删除"

test=$(echo 'cat //body/value/@name' | xmllint --shell "test.xml" | grep -v ">" | cut -f 2 -d "=" | tr -d \"); 
echo $test

#3

I recently had to port my original simpler solution using --xpath to a platform lacking this feature, so had to adopt the "cat" solution too. This will handle multiple matches, tested on Ubuntu 12.04 and Solaris 11:

我最近不得不将我最初使用的更简单的解决方案(xpath)移植到一个缺乏该特性的平台上，因此也必须采用“cat”解决方案。这将处理多个匹配，测试在Ubuntu 12.04和Solaris 11:

getxml() { # $1 = xml file, $2 = xpath expression
    echo "cat $2" | xmllint --shell $1 |\
    sed -n 's/[^\"]*\"\([^\"]*\)\"[^\"]*/\1/gp'
}

e.g. extracting instance names from a glassfish domain config:

例如，从glassfish域配置中提取实例名:

$ getxml /tmp/test.xml "//server[@node-ref]/@name"
inst1
inst2

The sed post-processing just grabs all quoted values which was adequate for my needs (getting bits of glassfish config).

sed后处理只获取所有引用的值，这些值足以满足我的需要(获取少量的glassfish配置)。

#4

An approach with a helper awk command that supports multiple attributes (a streamlined version of ego's approach):

一种支持多个属性的助手awk命令的方法(自我方法的简化版本):

echo 'cat //*/@name' | xmllint --shell file | awk -F\" 'NR % 2 == 0 { print $2 }'

The awk command:

awk命令:

splits xmllint's output lines into fields by " chars. (-F\")

将xmllint的输出行拆分为“chars”。(- f \”)
- Note that xmllint normalizes quoting around attribute values to "..." on output, even if the input had '...', so it's sufficient to split by ".
- 注意，xmllint在输出时将引用的属性值规范化为“…”，即使输入是“…”"，所以分裂就足够了"
only processes even-numbered lines (NR %2 == 0), thereby filtering out the separator lines that cat invariably prints.

只处理偶数编号的行(NR %2 == 0)，因此过滤掉cat总是打印的分隔线。
print $2 then prints only the 2nd field, which is the value of each attribute without the enclosing "...".

打印$2然后只打印第2个字段，这是每个属性的值，不包含“…”。

Assuming the following sample XML in file:

假设文件中有以下示例XML:

<body>
  <value name="abc"></value>
  <value name="def"></value>
</body>

the above yields:

上述收益率:

abc
def

#1