How do I search and replace a large block of text?

Question

I only have awk, sed, xmllint and ex available to me.

I need to modify a text file. What it is now:

        <!--
        <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
                   maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
                   enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
                   protocol="org.apache.coyote.http11.Http11NioProtocol"
                   scheme="http" proxyName="<subdomain>.<domain>.com" proxyPort="80"/>
        -->

I need to remove the XML comments and change the proxyName variable. What I need to change it to:

        <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
                   maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
                   enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
                   protocol="org.apache.coyote.http11.Http11NioProtocol"
                   scheme="http" proxyName="proxy.company.com" proxyPort="80"/>

There are several instances of this block in this file. I only want to change the block that contains:

scheme="http" proxyName="<subdomain>.<domain>.com" proxyPort="80"/>

Thanks!

Answer 1

If you can use xmllint you can probably use xmlstarlet. If so, you can use XSLT to do this. Unfortunately xmlstarlet only supports XSLT 1.0 so it's not a pretty solution, but it works.

XML Input (input.xml)

<doc>
    <!--
    <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
               maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
               enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
               protocol="org.apache.coyote.http11.Http11NioProtocol"
               scheme="http" proxyName="<subdomain>.<domain>.com" proxyPort="80"/>
    -->
    <foo/>
    <!--
    <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
               maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
               enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
               protocol="org.apache.coyote.http11.Http11NioProtocol"
               scheme="http" proxyName="ignore.me" proxyPort="80"/>
    -->
</doc>

XSLT 1.0 (test.xsl)

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output indent="yes"/>
    <xsl:strip-space elements="*"/>
    
    <xsl:template match="@*|node()">
        <xsl:copy>
            <xsl:apply-templates select="@*|node()"/>
        </xsl:copy>
    </xsl:template>
    
    <xsl:template match="comment()[
        contains(.,'scheme=&quot;http&quot;') and 
        contains(.,'proxyName=&quot;&lt;subdomain>.&lt;domain>.com&quot;') and 
        contains(.,'proxyPort=&quot;80&quot;')]">
        <xsl:value-of select="substring-before(.,'proxyName=&quot;&lt;subdomain>.&lt;domain>.com&quot;')" disable-output-escaping="yes"/>
        <xsl:text>proxyName="proxy.company.com"</xsl:text>
        <xsl:value-of select="substring-after(.,'proxyName=&quot;&lt;subdomain>.&lt;domain>.com&quot;')" disable-output-escaping="yes"/>
    </xsl:template>
    
</xsl:stylesheet>

Command line/Output (This can be redirected to an output file.)

==> xmlstarlet tr test.xsl input.xml 
<?xml version="1.0"?>
<doc>
    <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
               maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
               enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
               protocol="org.apache.coyote.http11.Http11NioProtocol"
               scheme="http" proxyName="proxy.company.com" proxyPort="80"/>
    <foo/><!--
    <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
               maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
               enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
               protocol="org.apache.coyote.http11.Http11NioProtocol"
               scheme="http" proxyName="ignore.me" proxyPort="80"/>
    --></doc>

Answer 2

Assuming a XML sample as

<context>
            <!--
        <Connector port="8090" connectionTimeout="20000" redirectPort="8443"
                   maxThreads="48" maxPostSize="16777216" minSpareThreads="10"
                   enableLookups="false" acceptCount="10" URIEncoding="UTF-8"
                   protocol="org.apache.coyote.http11.Http11NioProtocol"
                   scheme="http" proxyName="subdomain.example.com" proxyPort="80"/>
        -->
    <other>test</other>
</context>

Bash script

#!/bin/bash

# Extract comment content to a variable
comm="$(xmllint --xpath 'normalize-space(/context/descendant::comment()[contains(.,"example.com")])' tmp.xml | sed -ze 's/\n/\
/g')"
# get everything else
content="$(xmllint --xpath '/context/*[not(descendant::comment()[contains(.,"example.com")])]' tmp.xml | sed -ze 's/\n/\
/g')"
# set contents again

printf "%s\n" 'cd /context' "set ${comm} ${content}" 'save' 'bye' | xmllint --shell tmp.xml

Comment turned into element

<?xml version="1.0" encoding="UTF-8"?>
<context><Connector port="8090" connectionTimeout="20000" redirectPort="8443" maxThreads="48" maxPostSize="16777216" minSpareThreads="10" enableLookups="false" acceptCount="10" URIEncoding="UTF-8" protocol="org.apache.coyote.http11.Http11NioProtocol" scheme="http" proxyName="subdomain.example.com" proxyPort="80"/>
 <other>test</other>
</context>

Next, change the attribute value as described here Modifying in line attribute in XML using xmllint