my $found_any = 0;
...
sub search_all {
   unlink, $found_any++ if /.../;
}

# (repeat for search_none)

print "No files found!\n" unless $found_any;

##</code><code>##

if ($found_any) {
   print "$found_any files deleted.\n";
} else {
   print "No files were found to delete.\n";
}