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DSPLIT(1)	    UNIX Programmer's Manual		DSPLIT(1)



[1mNAME
     [0mdsplit - split/unsplit large files across floppies

[1mSYNOPSIS
     [0mdata stream | [1mdsplit [0m[ [1m-t title [0m] [ [1m-b blocksize [0m] [ [1m-F [0m] [
     [1m-f [0m] [ floppy-device ]
     [1mdsplit [0m[ [1m-t title [0m] [ [1m-b blocksize [0m] [ [1m-F [0m] [ [1m-f [0m] [
     floppy-device ] | data stream
     [1mdsplit -v [0m[ floppy-device ]

[1mDESCRIPTION
     [0mThis utility enables the user to take a data stream and put
     it onto a named sequence of floppy discs. Typical uses would
     be to put the output of _t_a_r or _c_p_i_o onto a disc set, if
     necessary formatting the floppies as required.

     It should appear at the end of a pipeline if it is required
     to save onto floppies, or at the beginning if it is required
     to recover from floppies.

     In each case the standard input or standard output should be
     left connected to a terminal, and the other one attached to
     a pipeline, enabling the program to determine the intended
     use from the context.

     The first disc should be loaded into the drive to begin
     with, and in the archive case is given a title, which may be
     specified using the [1m-t [0moption, alternatively it is prompted
     for on the terminal when the program starts. This title and
     a sequence number is put into the first block of each disc
     as the program proceeds, for subsequent checking when the
     archive is read back in.

     As each disc is filled, the program halts and prompts the
     user to unload the disc and load the next one.

     The [1m-b[0m_b_l_o_c_k_s_i_z_e option specifies a blocksize to be associ-
     ated with the data stream. When the data is subsequently
     recovered, the data will be written to the output in units
     of this size, which may be written explicitly as a number or
     as a number followed by [1mb [0mor [1mk [0mto represent blocks (of 512
     bytes) or kilobytes (i.e. 1024) bytes respectively.

     In the absence of the [1m-b [0moption, then a blocksize appropri-
     ate for the floppy is used (this is quite adequate for _t_a_r
     and _c_p_i_o).

     If the [1m-f [0moption is given, each disc is formatted before
     starting to write on it.

     The program check-reads the disc in every case to ensure
     that an existing disc is not about to be destroyed before



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DSPLIT(1)	    UNIX Programmer's Manual		DSPLIT(1)



     formatting or writing to the current disc and generates
     appropriate prompts for confirmation. Such checking may be
     disabled using the [1m-F [0moption.

     Note that an unformatted disc may cause error messages to be
     output on the console as the program check-reads the disc to
     see whether or not it has been formatted.

     If no floppy device name is given, then the standard floppy
     device, /_d_e_v/_r_f_d_f_1_0_2_4, is assumed.

     On recovery, the program checks that the archive floppies
     are loaded in the correct order, and also verifies the
     title. If this is specified using the [1m-t [0moption, then the
     program proceeds to process the first disc, and if the title
     matches, will make no comment. Otherwise, or if the title
     does not match, an appropriate message is generated and the
     program requests confirmation before proceeding, although
     this may be suppressed using the [1m-F [0moption. Messages about
     out-of-sequence or invalid discs cannot be suppressed, how-
     ever.

     The [1m-b[0m_b_l_o_c_k_s_i_z_e option specifies a blocksize to be associ-
     ated with the data stream. When the data is recovered, the
     data will be written to the output in units of this size,
     which may be written explicitly as a number or as a number
     followed by [1mb [0mor [1mk [0mto represent blocks (of 512 bytes) or
     kilobytes (i.e. 1024) bytes respectively.	If the data was
     written to the disc with a blocksize specified, and a block-
     size specified with this option does not match, this is
     queried before continuing.

     The sequence number put with the title on each disc includes
     the current date and time as each disc is processed as a
     further check, in case the same title is given each time.

     The program may also be invoked with the [1m-v [0moption and no
     data stream to display the title, sequence number and date
     and time of a given disc. However this is no substitute for
     a physical label.

[1mFILES
     [0m/dev/rfdf*

[1mSEE ALSO
     [0mcpio(1), dump(8), tar(1).









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