CODEWITHSUNDEEP
xmlbashdynamictextreplace
Clucky
Clucky

Reputation: 371

Replace dynamic content in XML file

Quick Summary: I need to create a Bash script to change the text within a node automatically every week. The script will match the node and replace the text inside them (if this is possible)? How would I do this?

Long Summary: I host a Minecraft server which has shops, each of which have their own .xml file in the /ShowcaseStandalone/ffs-storage/ directory. Every Sunday my server restarts and executes several commands into the terminal to reset several things. One thing that I am trying to make change is one of the shops. I am wanting to change the text in the node <itemstack> and the text in the node <price>. I am simply wanting to take text from a .txt file in a different folder, and insert it into that node. The problem is, that the text in the node will change every week. Is there any way to replace a specific line or text within two nodes using bash?

XML file:

<?xml version="1.0" encoding="UTF-8"?>
<scs-shop usid="cac8480951254352116d5255e795006252d404d9" version="2" type="storage">
    <enchantments type="string"/>
    <owner type="string">Chadward27</owner>
    <world type="string">Frisnuk</world>
    <itemStack type="string">329:0</itemStack>
    <activity type="string">BUY</activity>
    <price type="double">55.0</price>
    <locX type="double">487.5</locX>
    <locY type="double">179.0</locY>
    <locZ type="double">-1084.5</locZ>
    <amount type="integer">0</amount>
    <maxAmount type="integer">0</maxAmount>
    <isUnlimited type="boolean">true</isUnlimited>
    <nbt-storage usid="23dffac5fb2ea7cfdcf0740159e881026fde4fa4" version="2" type="storage"/>
</scs-shop>

Operating System: Linux Ubuntu 12.04

Upvotes: 20

Views: 23342

Answers (3)

Dan Bliss
Dan Bliss

Reputation: 1744

The XML way is cool, but if you need to use normal bash tools, you can modify a line using sed. For instance:

PRICE=123
sed -i "s/\(<price.*>\)[^<>]*\(<\/price.*\)/\1$PRICE\2/" $XML_FILE_TO_MODIFY

This will replace the price with 123.

That sed command seems daunting, so let me break it down:

\(<price.*>\)[^<>]*\(<\/price.*\) is the pattern to match. \( ... \) are parenthesis for grouping. <price.*> matches the opening price tag. [^<>]* matches anything except angle brackets, and in this case will match the contents of the price tag. <\/price.* matches the end of the price tag. Forward slash is a delimiter in sed, so I escape it with a back slash.

\1$PRICE\2 is the text to replace the matched text with. \1 refers to the first matched parenthesis group, which is the opening price tag. $PRICE is the variable with the desired price in it. \2 refers to the second parenthesis group, in this case the closing tag.

Upvotes: 16

Denn0
Denn0

Reputation: 397

I did not have the luxury of having xmlstarlet. I found a solution though simply by doing an inline replacement;

template-parameter.xml

<ns:Parameter>
    <ns:Name required="true">##-ParamName-##</ns:Name>
    <ns:Value>
        <ns:Text>##-ParamValue-##</ns:Text>
    </ns:Value>
</ns:Parameter>

Snippet

tokenName="foo"
tokenValue="bar"    

#Replace placeholders in parameter template element
myParamElement=$(cat template-parameter.xml)
myParamElement=${myParamElement//##-ParamName-##/$tokenName}
myParamElement=${myParamElement//##-ParamValue-##/$tokenValue}

Result

<ns:Parameter>
    <ns:Name required="true">foo</ns:Name>
    <ns:Value>
        <ns:Text>bar</ns:Text>
    </ns:Value>
</ns:Parameter>

Upvotes: 2

Gilles Qu&#233;not
Gilles Qu&#233;not

Reputation: 185560

You can use xmlstarlet to edit a XML file in a shell like this :

xmlstarlet edit -L -u "/scs-shop/price[@type='double']" -v '99.66' file.xml

NOTE

  • "/scs-shop/price[@type='double']" is a Xpath expression
  • see xmlstarlet ed --help

Upvotes: 19

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