open(MAP, "<$new_name_map_file");
while (<MAP>) {
     chomp;
     tr/A-Z/a-z/;
     @map_line = split (/\t/);
     $mapper{$map_line[0]} = $map_line[1];
}
close(MAP);
 
open(IN, "<input_file");
open(OUT, ">input_file.new");
while (<IN>) {
print "%";
     tr/A-Z/a-z/;
     foreach $key (sort keys %mapper) {
        s/\b$key\b/$mapper{$key}/g;
     }
     print OUT "$_";
}
close(IN);
clse(OUT);