In finding out, how to remove this "d", which is invisibly attached at the end of each line, I included into your script:

chomp wouldn't do!

The gethex function shows that "d" is removed without loosing the last letter (or number).

Later I will continue working on the question, how to parse the "bad" text file without the invisible "d" into my main script and use these shortened strings there as regex

better

The 'd' is 0d the hex code for a carriage return. This node has the details Why chomp() is not considering carriage-return

poj

Thanks for this link!

Is it correct, that this Carriage return (cr) is obviously not removed by chomp? And that this could be the reason, why the regex (including cr) can not be matched to the array elements of read_dir (which have no cr)?

Well, I will try to remove cr by defining $/ = "\r\n" and I will see if the script is running

better

...and later:

It works!!!

After parsing the csv file and writing the entries of the first coloumn into a text file, stripping of the carriage return. My main script "search and copy files" works.

Thanks to all monks, who helped me to find enlightenment ;-)

I'm feeling much better now

And here is the code:

#! /usr/local/bin/perl 
#
#script opens and parses CSV files
#removes carriage return
#and writes all into a new text file
#
#tested:  --ok!

use strict;
use warnings;
use Text::CSV;
#use Encode;         # probably not needed   :encoding(utf8)

 #Input CSV filename
 my $file = $ARGV[0];
 
 if (!$ARGV[0]) {
 $file = './data/IDs.csv'; #Default
 }
 
 if (!-f $file) {
 print "Kann Datei $file nicht finden: $!\n";
 exit 1;
 }
 
 #Parsing CSV
 local $/ = "\r\n";        #add windows carriage return to perl's eol 
+(newline)
 
 my $csv = Text::CSV ->new ({binary =>1, eol => $/});
 
 open (my $fhCSV, '<', $file) or die "Kann $file nicht öffnen $!\n";
 open (my $fhOUT, '>', './data/IDs.txt') or die "Kann Datei nicht öffn
+en: $!\n";
 
 while (my $line = <$fhCSV>) {
        if ($csv->parse($line)) {
        my @fields = $csv->fields ();
        chomp (@fields);
        print $fhOUT "@fields\n";
        }
        else {
        warn "Line could not be parsed: $line\n";
        }
 }
 print "CSV parsed and saved as text file: /data/IDs.txt!";
 close $fhCSV;
 close $fhOUT;
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