use strict;
use warnings;
open my $fh, '<', 'hash_test.txt' 
    or die "Cant open file $!";

LINE:
while (my $line = <$fh>) 
	{
    	my ($key, $value) = split /\s/, $line;
    	next LINE if not $key;
		$hash{$key} = $value;
    	chomp (%hash);
    	while ( my( $key, $value ) = each %hash )  		
	}

close $fh;

##</code><code>##

open FH, "<infile.txt" or die $!;
open OUT, ">outfile.txt";

 while (<FH>)
          {
          if (/(\S+):(\S+).*\n/)
               {
               $var1 = "$1";
               $var2 = "$2";
               print OUT "$hash{$var1} $var2\n";
               }
        	elsif (/(.*)\n/)
        		{
        		print OUT "$1\n";
               }
            }
     close FH;