spantape - span single pipe across multiple SCSI tapes
version 1.02 (c) 2005 Sebastian Zagrodzki <s.zagrodzki@net.icm.edu.pl>

This software is distributed under the GNU General Public License

Usage:  ./spantape -r <device> [-options] [> out]  -  read backup from tapes
        ./spantape -w <device> [-options] [< in]   - write backup to tapes
Options:
	-c <command>    command to execute when changing tapes. Should be in
                        form suitable for system(). Substituted %-entities:
                        %m (r for read, w for write), %i (backup id),
                        %n (tape no), %b (bytes read from/written to tape),
                        %B (bytes read/written total so far),
                        %r and %R (like %b and %B, but blocks not bytes).
                        One can use SPANTAPE_* environment variables:
                        ID, MODE, TAPENO, {BYTES,BLOCKS}_{TAPE,TOTAL}
                        Should return 0 on success, 1 on success & stop
                        (only for read mode), anyting else on error

	-b <blocksize>  desired block size. Can use multiplicative suffixes:
                        k (1000), K (1024), m (1000^2)  and M (1024^2)

        -n <max_tapes>  Maximum number of tapes to use
        -i <id>         backup ID. Default is to use random 16-digit hex number
        -f <filename>   use <filename> instead of stdin/stdout
        -T              don't use backup ID tags. Implies -E, excludes -i
        -E              don't write finish ID tag
        -F              run -c command before reading/writing first tape
        -L              run -c command after reading/writing last tape (%n == 0)
        -d              set debug mode on
        -V              version info
        -h              this help