Merge content of one file into another file by replace a function

Question

I am working on a shell script which is getting data from another program and I am using that variable value to read the content from file keep appending to different files after some modification to it:

Below is an example:

readonly file_location=$location
readonly client_id = $id
readonly client_types = $type_of_client

Here $location, $id and $type_of_client value is being passed from another program. Below is an example:

$location will be full path name like this: /home/david/data/12345678 $id will be number: 120 $type_of_client will be space separted word: abc def pqr

Now inside this location /home/david/data/12345678 I have files like this: abc_lop.xml, def_lop.xml and pqr_lop.xml. Meaning _lop.xml is going to be same always so we can hardcode this. We just need to iterate client_types variable and make a file name as shown above and append header and footer into those file and make a new one. So I got this part working fine with below code:

#!/bin/bash

readonly file_location=$location
readonly client_id=$id
readonly client_types=$type_of_client

client_value=`cat "$file_location/client_$client_id.xml"`

for word in $client_types; do
    fn="${word}"_new.xml
    echo "$word"
    echo '<hello_function>' >>"$fn"
    echo '<name>Data</name>' >>"$fn"
    cat "$file_location/${word}_lop.xml" >>"$fn"
    echo '</hello_function>' >>"$fn"
done

Now second thing which I need to do is: I have an another xml file which is client_$client_id.xml. I need to copy my generated _new.xml file into client_$client_id.xml at a particular location. Below is my client_120.xml in which I need to add my generated _new.xml file. I need to replace whole below function with my generated _new.xml file.

<?xml version="1.0"?>

<!-- some data -->

        <function>
            <name>TesterFunction</name>
            <datavariables>
                <name>temp</name>
                <type>string</type>
            </datavariables>
            <blocking>
                <evaluate>val = 1</evaluate>
            </blocking>
        </function>
    </model>
</ModelMetaData>

So if this is my generated _new.xml file: I need to copy this whole file into above file and replace whole TesterFunction with it.

<hello_function>
<name>Data</name>
<Hello version="100">

<!-- some stuff here -->

</Hello>
</hello_function>

So final output will be like this:

<?xml version="1.0"?>

<!-- some data -->

    <hello_function>
    <name>Data</name>
    <Hello version="100">

    <!-- some stuff here -->

    </Hello>
    </hello_function>
    </model>
</ModelMetaData>

Answer 1

This should do it:

#!/bin/bash

readonly file_location="$location"
readonly client_id="$id"
readonly client_types="$type_of_client"

## Define the header and footer variables
header='<hello_function>
<name>Data</name>'
footer='</hello_function>'

for word in $client_types
do
    ## Concatenate the header, the contents of the target file and the
    ## footer into the variable $file.
    file=$(printf '%s\n%s\n%s' "$header" "$(cat "$file_location/${word}_lop.xml")" "$footer")

    ## Edit the target file and print
    perl -0pe "s#<function>\s*<name>DUMMYPMML.+?</function>#$file#sm"  model_"$client_id".xml
done