while (my $line = <$FH_IN>) { 
    chomp $line; #removes line break or new line;
    my $url_sub = "";           
           print "processing file $counter,\n";
# Within each record, loop until a match occurs with "subsid" in the record,;
# and the record contains a URL address, and the URL contain a derivative; 
# of Exhibt 21, e.g., ex21, ex-21, exhibit21, or exhibt-21;             
           while ($line =~ m/subsidiar/igm && $line =~ m/\/Archives(.*)">/igm &&
                 ($line =~ m/ex21/igm || $line =~ m/EX\-21/igm || 
                  $line =~ m/exhibit\-21/igm || $line =~ m/exhibit21/igm)  ) {
                $url_sub = $1;    #extract the match and assign to variable;      
                #Join the match with the standard URL prefix;     
                my $url = join("",$base_url,$url_sub);   
                print $url;
                open my $FH_OUT, '>>',$write_dir or die "Can't open file $write_dir >:$!>";              
                print $FH_OUT "$url\n"; 
                ++$counter;        
           }     #End of while loop for extracting matching text;
           
}    #End of record;