open my $input, '<', "my_input.xml" or die "Can't open my_input.csv: $!"; # Whoops, my_input.xml does not exist by my_input.csv file does

my $input_file = "my_input.xml";
open my $input, '<', $input_file or die "Can't open $input_file: $!"; # Still doesn't work but the error message is correct

##</code><code>##

my $file = get_file(); 
my $folder = get_folder(); # The function returned an empty string by mistake
open my $data, '<', "$folder/$file" or die "Can't open $file; $!"; # But I see the file my folder, why does it say it doesn't exist?

my $input_file = "$folder/$input";
open my $data, '<', $input_file or die "Can't open $input_file: $!"; # You'll see straightaway that you the folder is empty