如何使用 xmlstarlet 在另一个元素下插入一个新元素？

发布于 2024-11-06 14:26:36 字数 580 浏览 6 评论 0原文

$ vim test.xml

<?xml version="1.0" encoding="UTF-8" ?>
<config>
</config>
$ xmlstarlet ed -i "/config" -t elem -n "sub" -v "" test.xml
<?xml version="1.0" encoding="UTF-8"?>
<sub></sub>
<config>
</config>

但我希望 sub 成为 config 的子项。我应该如何更改 -i 的 xpath 参数？

奖金：是否可以直接使用属性插入子项，甚至将其设置为一个值？像这样的东西：

$ xmlstarlet ed -i "/config" -t elem -n "sub" -v ""  -a attr -n "class" -v "com.foo" test.xml

原文

$ vim test.xml

<?xml version="1.0" encoding="UTF-8" ?>
<config>
</config>
$ xmlstarlet ed -i "/config" -t elem -n "sub" -v "" test.xml
<?xml version="1.0" encoding="UTF-8"?>
<sub></sub>
<config>
</config>

But I wanted sub to be a child of config. How should I change the xpath parameter of -i?

BONUS:
Is it possible to insert the child directly with an attribute and even have it set to a value?
Something like:

$ xmlstarlet ed -i "/config" -t elem -n "sub" -v ""  -a attr -n "class" -v "com.foo" test.xml

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染柒℉ 2024-11-13 14:26:37

我遇到了类似的问题：我有一个 Tomcat 配置文件 (server.xml)，并且必须将带有预定义属性的标记插入 < /代码> 部分。

这是它之前的样子：

<GlobalNamingResources>
    <!-- Editable user database that can also be used
         by UserDatabaseRealm to authenticate users
    -->
    <Resource name="UserDatabase"
              auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>

这是我想要实现的目标：

<GlobalNamingResources>
    <!-- Editable user database that can also be used
         by UserDatabaseRealm to authenticate users
    -->
    <Resource name="UserDatabase"
              auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
    <Resource name="jdbc/templateassets"
              auth="Container"
              type="javax.sql.DataSource"
              driverClassName="com.mysql.jdbc.Driver"
              url="jdbc:mysql://DBHOST:DBPORT/DBNAME?createDatabaseIfNotExist=false&useUnicode=true&characterEncoding=utf-8"
              username="DBUSER"
              password="DBPASS"
              maxActive="150"
              maxIdle="10"
              initialSize="10"
              validationQuery="SELECT 1"
              testOnBorrow="true" />
</GlobalNamingResources>

这是我的做法（来自 shell 脚本的片段）：

if [ -n "$(xmlstarlet sel -T -t -v "/Server/GlobalNamingResources/Resource[@name='jdbc/templateassets']/@name" server.xml)" ]; then
  echo "Resource jdbc/templateassets already defined in server.xml"
else
  echo "Adding resource jdbc/templateassets to <GlobalNamingResources> in server.xml"
  xmlstarlet ed -P -S -L -s /Server/GlobalNamingResources -t elem -n ResourceTMP -v "" \
    -i //ResourceTMP -t attr -n "name" -v "jdbc/templateassets" \
    -i //ResourceTMP -t attr -n "auth" -v "Container" \
    -i //ResourceTMP -t attr -n "type" -v "javax.sql.DataSource" \
    -i //ResourceTMP -t attr -n "driverClassName" -v "com.mysql.jdbc.Driver" \
    -i //ResourceTMP -t attr -n "url" -v "jdbc:mysql://DBHOST:DBPORT/DBNAME?createDatabaseIfNotExist=false&useUnicode=true&characterEncoding=utf-8" \
    -i //ResourceTMP -t attr -n "username" -v "DBUSER" \
    -i //ResourceTMP -t attr -n "password" -v "DBPASS" \
    -i //ResourceTMP -t attr -n "maxActive" -v "150" \
    -i //ResourceTMP -t attr -n "maxIdle" -v "10" \
    -i //ResourceTMP -t attr -n "initialSize" -v "10" \
    -i //ResourceTMP -t attr -n "validationQuery" -v "SELECT 1" \
    -i //ResourceTMP -t attr -n "testOnBorrow" -v "true" \
    -r //ResourceTMP -v Resource \
    server.xml
fi

诀窍是临时为新元素指定一个唯一的名称，以便以后可以找到它带有 XPATH 表达式。添加所有属性后，名称将更改回 Resource（使用 -r）。

其他xmlstarlet选项的含义：

-P (or --pf)        - preserve original formatting
-S (or --ps)        - preserve non-significant spaces
-L (or --inplace)   - edit file inplace

I had a similar problem: I had a Tomcat configuration file (server.xml), and had to insert a <Resource> tag with pre-defined attributes into the <GlobalNamingResources> section.

Here is how it looked before:

<GlobalNamingResources>
    <!-- Editable user database that can also be used
         by UserDatabaseRealm to authenticate users
    -->
    <Resource name="UserDatabase"
              auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>

Here is what I wanted to achieve:

<GlobalNamingResources>
    <!-- Editable user database that can also be used
         by UserDatabaseRealm to authenticate users
    -->
    <Resource name="UserDatabase"
              auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
    <Resource name="jdbc/templateassets"
              auth="Container"
              type="javax.sql.DataSource"
              driverClassName="com.mysql.jdbc.Driver"
              url="jdbc:mysql://DBHOST:DBPORT/DBNAME?createDatabaseIfNotExist=false&useUnicode=true&characterEncoding=utf-8"
              username="DBUSER"
              password="DBPASS"
              maxActive="150"
              maxIdle="10"
              initialSize="10"
              validationQuery="SELECT 1"
              testOnBorrow="true" />
</GlobalNamingResources>

Here is how I did it (snippet from a shell script):

if [ -n "$(xmlstarlet sel -T -t -v "/Server/GlobalNamingResources/Resource[@name='jdbc/templateassets']/@name" server.xml)" ]; then
  echo "Resource jdbc/templateassets already defined in server.xml"
else
  echo "Adding resource jdbc/templateassets to <GlobalNamingResources> in server.xml"
  xmlstarlet ed -P -S -L -s /Server/GlobalNamingResources -t elem -n ResourceTMP -v "" \
    -i //ResourceTMP -t attr -n "name" -v "jdbc/templateassets" \
    -i //ResourceTMP -t attr -n "auth" -v "Container" \
    -i //ResourceTMP -t attr -n "type" -v "javax.sql.DataSource" \
    -i //ResourceTMP -t attr -n "driverClassName" -v "com.mysql.jdbc.Driver" \
    -i //ResourceTMP -t attr -n "url" -v "jdbc:mysql://DBHOST:DBPORT/DBNAME?createDatabaseIfNotExist=false&useUnicode=true&characterEncoding=utf-8" \
    -i //ResourceTMP -t attr -n "username" -v "DBUSER" \
    -i //ResourceTMP -t attr -n "password" -v "DBPASS" \
    -i //ResourceTMP -t attr -n "maxActive" -v "150" \
    -i //ResourceTMP -t attr -n "maxIdle" -v "10" \
    -i //ResourceTMP -t attr -n "initialSize" -v "10" \
    -i //ResourceTMP -t attr -n "validationQuery" -v "SELECT 1" \
    -i //ResourceTMP -t attr -n "testOnBorrow" -v "true" \
    -r //ResourceTMP -v Resource \
    server.xml
fi

The trick is to temporarily give a unique name to the new element, so that it can be found later with an XPATH expression. After all attributes have been added, the name is changed back to Resource (with -r).

The meaning of the other xmlstarlet options:

-P (or --pf)        - preserve original formatting
-S (or --ps)        - preserve non-significant spaces
-L (or --inplace)   - edit file inplace

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久光 2024-11-13 14:26:37

使用-s（或--subnode）而不是-i。关于好处，您不能直接插入带有属性的元素，但由于每个编辑操作都是按顺序执行的，因此插入元素然后添加属性：

> xml ed -s /config -t elem -n sub -v "" -i /config/sub -t attr -n class -v com.foo test.xml
<?xml version="1.0" encoding="UTF-8"?>
<config>
<sub class="com.foo"></sub></config>

Use -s (or --subnode) instead of -i. Regarding the bonus, you can't insert an element with an attribute directly but since every edit operation is performed in sequence, to insert an element and then add an attribute:

> xml ed -s /config -t elem -n sub -v "" -i /config/sub -t attr -n class -v com.foo test.xml
<?xml version="1.0" encoding="UTF-8"?>
<config>
<sub class="com.foo"></sub></config>

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缱倦旧时光 2024-11-13 14:26:37

从 XMLStarlet 1.4.0 版（日期为 2012-08-26）开始，您可以使用 $prev （或 $xstar:prev）作为 - 的参数i、-a 和 -s 引用最后插入的节点集。请参阅文件 doc/xmlstarlet.txt，examples/ed-backref1、examples/ed-backref2 和examples/ed-backref-delete。您不再需要使用使用临时元素名称插入元素然后在最后重命名的技巧。该示例 examples/ed-backref2 特别有用展示如何定义一个变量来引用先前创建的注释，这样您就不需要执行诸如 $prev/.. 之类的技巧来“导航”出一个节点。

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糖果控 2024-11-13 14:26:37

正如@npostavs提到的，正确的答案是使用“子节点”。要使用新的“$prev”改进答案，您可以执行以下操作：

xml ed --inplace \
       --subnode /config --type elem --name "sub" \
       --var new_node '$prev' \
       --insert '$new_node' --type attr --name "class" --value "com.foo" \ 
       test.xml

使用以下说明：

--inplace    Change the file "test.xml" directly
--subnode    Add a new node called "class" below "/config"
--var        Assign the newly created node to the variable new_node 
             Use single quotes to prevent bash replacing the variable
--insert     Insert attribute and value to the newly created node

As mentioned by @npostavs the correct answer is to use 'subnode'. To improve the answer with the new '$prev' you can do the following:

xml ed --inplace \
       --subnode /config --type elem --name "sub" \
       --var new_node '$prev' \
       --insert '$new_node' --type attr --name "class" --value "com.foo" \ 
       test.xml

With the following explanation:

--inplace    Change the file "test.xml" directly
--subnode    Add a new node called "class" below "/config"
--var        Assign the newly created node to the variable new_node 
             Use single quotes to prevent bash replacing the variable
--insert     Insert attribute and value to the newly created node

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