my $path = "/path-to/some-dir";
opendir(DIR, $path) || die "Could not read $path - $!\n";
for my $fileFound (grep /^loyl\d+i_lgr\.sss$/, readdir(DIR)) {
   # do stuff here...
}

##</code><code>##

my $path = "/path-to/some-dir";
opendir(DIR, $path) || die "Could not read $path - $!\n";
while (my $fileFound = readdir(DIR)) {
   next unless $fileFound =~ /^loyl\d+i_lgr\.sss$/
   # do stuff here...
}