Remove line break characters in multi-line XML element - perl

Question

On a Unix system I have an input text file containing long multi-line strings.
I now want to remove line breaks only between two patterns ( and ) which can be on different lines.
Example input file:
text1 text2 <remarks> text3
text4 text5 </remarks> text6 text7 text8
Result output for the above input file should be:
text1 text2 <remarks> text3 text4 text5 </remarks> text6 text7 text8
I would prefer to use sed or Perl or maybe awk to do the job.
I do not see a solution as the newlines can happen "randomly" and text is just some log messages.
Here is a more detailed look of the input file I need to process. It does not contain a root XML section, but for testing I might just add one manually. Also there may be many "remarks" sections.
Inputfile Snippet (as it is very long), Filename is test:
<paymentTerm keyValue1="8" objectType="PAYMENTTERM" />
<paymentType keyValue1="20" objectType="PAYMENTTYPE" />
<priceList keyValue1="1" objectType="PRICELIST" />
<remarks>Zollanmeldung ab 250 €
Lager Adresse:
Hessen-Ring 456
D-64546 Mörfelden-Walldorff
eine Stunde vor Ankunft melden unter Mobile
Neu Spedition
A&R Logistics Group
Storkenburgstrasse 99
D-62546 Mörfelden-Walldorf
www.asp.de</remarks>
<salesPersons>
<PERSON keyValue1="2" keyValue2="SALESEMPLOYEE" objectType="PERSON" />
</salesPersons>
<shippingType keyValue1="5" objectType="SHIPPINGTYPE" />
As stated above I want to remove the linebreaks ONLY between the patterns "remarks" and "/remarks".
I tried the Perl XML Parsing suggested by borodin like this:
use strict;
use warnings 'all';
use XML::Twig;
use constant XML_FILE => 'test';
my $twig = XML::Twig->new(
twig_handlers => {
remarks => sub { $_->set_text($_->trimmed_text) }
}
);
$twig->parsefile(XML_FILE);
$twig->print;
It works, but prints everything on one line.

Answer 1

With GNU awk for multi-char RS:
$ awk -v RS='</?remarks>' -v ORS= '!(NR%2){gsub(/\n/,OFS)} {print $0 RT}' file
text1 text2 <remarks> text3 text4 text5 </remarks> text6 text7 text8

Answer 2

XML can represent the same information in many different ways, and it is always a risk to try processing it using regular expressions. It is far better to use a proper XML module to process XML data. This solution uses
XML::Twig
In the constructor for the $twig object you can specify a callback which is called automatically every time a given XML element is encountered in the input
The trimmed_text method removes leading and trailing whitespace from the text of the element, and turns any internal whitespace sequences, including line breaks, into a single space. That is exactly what you are asking for here, so a call to set_text is all that is necessary to update the string
The file to be processed is specified by the XML_FILE constant and you should modify that to specify the path to your own data file. The modified XML is printed to STDOUT
use strict;
use warnings 'all';
use open qw/ :std :encoding(UTF-8) /;
use XML::Twig;
use constant XML_FILE => 'remarks.xml';
my $twig = XML::Twig->new(
keep_spaces => 1,
twig_handlers => {
remarks => sub { $_->set_text($_->trimmed_text) }
}
);
$twig->parsefile(XML_FILE);
$twig->print;
input
Your sample data is invalid XML, so I have edited it to look like this. I have added the XML declaration that you said in a comment that you had, and I have added a root element <data>
<?xml version="1.0" encoding="UTF-8"?>
<data>
<paymentTerm keyValue1="8" objectType="PAYMENTTERM" />
<paymentType keyValue1="20" objectType="PAYMENTTYPE" />
<priceList keyValue1="1" objectType="PRICELIST" />
<remarks>Zollanmeldung ab 250 €
Lager Adresse:
Hessen-Ring 456
D-64546 Mörfelden-Walldorff
eine Stunde vor Ankunft melden unter Mobile
Neu Spedition
A&R Logistics Group
Storkenburgstrasse 99
D-62546 Mörfelden-Walldorf
www.asp.de</remarks>
<salesPersons>
<PERSON keyValue1="2" keyValue2="SALESEMPLOYEE" objectType="PERSON" />
</salesPersons>
<shippingType keyValue1="5" objectType="SHIPPINGTYPE" />
</data>
output
<?xml version="1.0" encoding="UTF-8"?>
<data>
<paymentTerm keyValue1="8" objectType="PAYMENTTERM"/>
<paymentType keyValue1="20" objectType="PAYMENTTYPE"/>
<priceList keyValue1="1" objectType="PRICELIST"/>
<remarks>Zollanmeldung ab 250 € Lager Adresse: Hessen-Ring 456 D-64546 Mörfelden-Walldorff eine Stunde vor Ankunft melden unter Mobile Neu Spedition A&R Logistics Group Storkenburgstrasse 99 D-62546 Mörfelden-Walldorf www.asp.de</remarks>
<salesPersons>
<PERSON keyValue1="2" keyValue2="SALESEMPLOYEE" objectType="PERSON"/>
</salesPersons>
<shippingType keyValue1="5" objectType="SHIPPINGTYPE"/>
</data>