#                    S P L I T P D 0 

#                    dlm: Sat Jul 30 18:50:43 2016

#                    uE-Info: 69 60 NIL 0 0 72 2 2 4 NIL ofnI

#	Sep 14, 2014: - added -f)irst

#	Jul 26, 2016: - changed file numbering to 1-relative

#	Jul 30, 2016: - modified -o default

#				  - added code to set DSID of first ensemble of each

#					output file to 0x7f7f

#     by default, an underscore and the yoyo cast number is added to the basename

	"[-o)ut-file <fmt[e.g. 017DL_%02d.000]>] " .

unless (defined($opt_o)) {

	my($bn,$extn) = ($ARGV[0] =~ m{([^/]+)\.([^\.]+)$});

	$opt_o = "${bn}_%02d.$extn";

}

$opt_m = 0 unless defined($opt_m);								# default: produce tiny files as well

readHeader($ARGV[0],\%hdr); shift;								# get length of ensembles

$first_ens = $ARGV[0]+1; shift;									# initialize loop

$cnr = 1;

do {															# split data

	sysseek(WBRF,($first_ens-2)*$ens_len,0) ||					# begin next block of ensembles

	sysread(WBRF,$ids,2) || die("$WBRcfn: file truncated");		# read 1st ensemble & ensure DSID is 0x7f

	$ids = pack('H4','7f7f');									# reset DSID

	sysread(WBRF,$febuf,$ens_len-4) == $ens_len-4 ||

		die("$WBRcfn: file truncated");

	sysread(WBRF,$csum,2) || die("$WBRcfn: file truncated");

	$csum = pack('v',unpack('%16C*',$ids.$febuf));				# re-calculate checksum

	$nBytes = ($last_ens-$first_ens) * $ens_len;				# read remaining ensembles in block

	if ($last_ens-$first_ens+1 >= $opt_m) {						# write output only if sufficient # of ensembles

		syswrite(F,$ids.$febuf.$csum.$buf,$nBytes+$ens_len) == $nBytes+$ens_len ||

	    printf(STDERR "$fn: %d ensembles (%d bytes)\n",

						$last_ens-$first_ens+1,$nBytes+$ens_len);