open (DFILE,$dfile) or die "can not open";
open (SFILE,$sfile) or die "can not open";
open (TFILE,"> $tfile") or die "can not open";

##</code><code>##

open DFILE, '<', $dfile or die "can not open '$dfile' because: $!";
open SFILE, '<', $sfile or die "can not open '$sfile' because: $!";
open TFILE, '>', $tfile or die "can not open '$tfile' because: $!";

##</code><code>##

        $words{$key} .= exists $words{$key} ? "$val" : $val;

##</code><code>##

        $words{$key} .= $val;

##</code><code>##

while (my $s = <SFILE>) {
chomp($s);
my @words = split / /, $s;

##</code><code>##

while ( <SFILE> ) {
    my @words = split;

##</code><code>##

   for my $i (0 .. $#words) {
     $words[$i] = $words{$words[$i]} if (exists($words{$words[$i]}))
        }

##</code><code>##

    for my $word ( @words ) {
        $word = $words{ $word } if exists $words{ $word };
        }

##</code><code>##

   print TFILE join(' ', @words),$/;
   print TFILE "<br>";

##</code><code>##

    print TFILE "@words\n<br>";

##</code><code>##

\ca \ra \ka \tl

##</code><code>##

\ca\ra\ka\tl 

##</code><code>##

$ perl -le'$_ = q/\ca\ra\ka\tl/; print; print for split /(?=\\)/'
\ca\ra\ka\tl
\ca
\ra
\ka
\tl