chdir $srcdir or die "Can't chdir to '$srcdir': $!\n";
open my $indir, '.' or die "Can't read '.' in $srcdir: $!\n";

(my $tarfile = $srcdir) =~ s|.*/||;
$tarfile = "$destdir/$tarfile-" . time . '.tar';

my @files = grep { -f and -M <= 1 } readdir $indir;

# packing all files at once doesn't work with large directories
# (limit of command line length)

while(my $file = shift @files) {
    system ('tar', 'uf', $tarfile, $file)
        and die "Can't pack '$file' into '$tarfile' (exitcode $?)\n"; 
}

system ('gzip', $tarfile)
    and die "Couldn't gzip $tarfile (exitcode $?)\n";