#!/usr/bin/perl
use strict;
use warnings;

for my $filename (@ARGV) {
    open my $in, '<', $filename or die;
    open my $out, '>', "$filename.xml" or die;
    local $/;
    my ($head, $body) = split (/\n(?=[A-Z])/, <$in>, 2);
    if ($head && body) {
        print $out "<heading>\n$head\n</heading>\n";
        print $out "<text>\n$body</text>\n";
    }
}

#!/usr/bin/perl
use strict;
use warnings;

# Change the directory source passing an argument
my $source_dir = shift || '.';

# Modify this to another directory
my $destination_dir = '/tmp';

# Modify the filename pattern
my $file_pattern = qr{file\d+\.txt};

opendir my $dh, $source_dir || die "Can't opendir $source_dir: $!";
my @file_list = grep {/^$file_pattern$/} readdir($dh);
while( my $filename = <@file_list> ) {
    open my $in, '<', "${source_dir}/$filename" or next;
    open my $out, '>', "${destination_dir}/$filename" or next;
    local $/;
    my ($head, $body) = split (/\n(?=[A-Z])/, <$in>, 2);
    if($head) {
        print $out "<heading>\n$head\n</heading>\n";
        print $out "<text>\n$body</text>\n";
    }
}
closedir $dh;