9.7;rwmt (read_write_magtape), revision 9.7, 87/10/06
RWMT (READ_WRITE_MAGTAPE) -- Read/write foreign magtapes.
usage: RWMT {-R|-W|-I|-L} [pathname]... [option]... [-Prompt] {CL}
FORMAT
RWMT mode_control [pathname...] [options]
RWMT reads tapes from non-DOMAIN installations and writes tapes which can be
read by non-DOMAIN installations. RWMT can read and write unlabeled tapes, as
well as ANSI level 1-4 labeled tapes.
For information on reading and writing tapes intended for exchange with other
DOMAIN installations, see HELP RBAK and HELP WBAK.
COMMAND LINE SUMMARY (Complete description follows.)
-R causes one or more tape files to be read & stored on disk
-W causes one or more disk files to be written to tape
-I causes an ANSI-labeled physical tape volume to be indexed
-L causes ANSI volume labels to be written on a physical tape
volume
-ANSI specifies that the tape is labeled in conformance to ANSI
X3.27-1978, level 1, 2, 3, or 4 (default)
-UNLAB specifies that the tape is unlabeled
-ASC specifies that all tape file contents are in ASCII (default)
-EBC specifies that all tape file contents (not labels) are in
EBCDIC
-RAW specifies that all tape file data is to be treated in raw form
-VID volid specifies a 1-6 character volume ID. Use when labeling volume
(-L argument) (default = ' ')
-OWN ownerid specifies a 1-14 character owner ID. Use when labeling volume
(-L argument) (default = ' ')
-FID fileid specifies a 1-17 character file ID to be written in the file
header label. Use when writing a file to a labeled volume
(-W argument) (default is 1st 17 characters of right-most
pathname component)
-F fileno|CUR|END
specifies a tape file sequence number. Use when reading or
writing a file (-R or -W argument); if multiple pathnames are
supplied, this value is incremented by one after each file
has been read or written. If "CUR" is supplied in lieu of
an ordinal file number, the file at the current tape position
is used; the tape must have previously been read or written
by RWMT and its position must not have been disturbed.
"END" causes the backup file to be written at the very end
of the file set.
(default = 1)
-RL reclen specifies the length, in bytes, of a record in the tape file.
(default = 80)
-BL blocklen specifies the length, in bytes, of a physical tape block.
(default = 80)
-BF blockfac specifies a blocking factor; this is an alternative to the
-BL option.
-RF format specifies record format - 'F' for fixed length records and
blocks, 'D' for variable length records, 'S' for spanned
records, or 'U' for undefined record format. (default = 'F')
-PAR causes parity bits to be forced off when reading data from
tape and forced on when writing data to tape
-NPAR causes no disturbance of parity bits when reading or writing
data (default)
-DEV d[unit] specifies the magtape device type and unit number (default = 0)
-RETEN retension a cartridge tape
-NRETEN do not retension a cartridge tape
-SBIN causes all stream files written to contain the "binary"
attribute (normally, output stream files contain the
"ascii" attribute)
-P causes RWMT to query for all unspecified options.
FULL DESCRIPTIONS
ARGUMENTS
pathname
(optional) Specify name of file to be read from or written to tape.
This argument is only valid with the -R and -W mode control
options (below). Multiple pathnames are permitted.
Wildcarding is permitted for write (-W) operations only.
Default if omitted: read pathnames from standard input.
OPTIONS
Default options are indicated by "(D)."
Mode control
One of the following mode control options must be specified. If you omit it,
RWMT will prompt you for it. You may have RWMT prompt for all necessary
options by using the -P option.
-L[ABEL] Write ANSI X3.27-1978 volume label on a tape. This option
causes RWMT to write an ANSI volume label and dummy file on
the magtape volume. An optional owner and volume ID, which
are stored in the volume label, may be specified (see -VID
and -OWN below). This is the way to initialize a labeled
tape; if any information existed on the tape, it is erased
by this labeling operation.
If you are labeling a tape, then the following two options
may also be used.
-VID volid Specify a 1-6 character volume ID for use
when labeling a volume. This option is
only valid when used with the -L
mode_control option (above). The default
volume ID is ' ' (blank).
-OWN ownerid Specify a 1-14 character owner ID for use
when labeling a volume. This option is only
valid when used with the -L mode control
option (above). The default owner ID is ' '
(blank).
-I[NDEX] List objects on an ANSI-labeled physical tape volume.
-INDEX produces a listing of all files or file sections on
an ANSI-labeled physical tape volume. The contents of the
physical volume (VOL1) label and all file header labels are
written to standard output.
-W[RITE] Specify one or more disk files ('pathname' argument) to be
written to tape. The default format is ANSI labeled,
ASCII, fixed-length records of 80 bytes each, and 80-byte
blocks. If desired, any of these parameters can be changed
using the options described below. If more than one
pathname is specified, the disk files are written to
sequential tape files. Tapes written by RWMT are always in
accordance with ANSI level 4 format.
Before writing a labeled file, the tape volume itself must
be labeled with the -LABEL mode control option (above).
-R[EAD] Specify one or more tape files to be read from tape and
stored on disk. READ reads one or more tape files and
writes them to disk using the specified pathnames
('pathname' argument). The default tape file format is the
same as that for the WRITE option. If the tape is labeled
under ANSI level 2, 3, or 4, the file format (block length,
record length, and record format) is read from the tape.
If the tape is unlabeled, or labeled with ANSI level 1, you
must specify the tape format using the options below. If
more than one pathname is specified, adjacent tape files
are read and stored under the specified pathnames.
Label Control
-ANSI (D) Specify that the tape is labeled in conformance to ANSI
X3.27-1978, level 1, 2, 3, or 4.
-UNLAB Specify that the tape is unlabeled. Data spanning physical
volumes is not supported on unlabeled tapes.
Tape Format
-ASC (D) Specify that all tape file contents are in ASCII
characters.
-EBC Specify that all tape file contents (except labels) are in
EBCDIC characters.
-RAW Specify that all tape file data is to be treated in raw
form (see example 5).
-NPAR (D) Specify no disturbance of parity bits when reading or
writing data.
-PAR Specify that parity bits should be forced off when reading
data from tape and forced on when writing data to tape.
-RL reclen Specify the maximum length, in bytes, of a record in the
tape file. This option is only valid when used with either
the -R or -W mode control options (above). It is unnecesary
when reading an ANSI level 2, 3, or 4 file. The default
record length is 80 bytes.
-BL blocklen Specify the length, in bytes, of a physical tape block.
This option is only valid when used with either the -R or
-W mode control options (above). It is unnecesary when
reading an ANSI level 2, 3, or 4 file. The default block
length is 80 bytes.
-BF blockfac Specify a blocking factor -- the number of records to store
into or read from a physical tape block. This is an
alternative to the -BL option, since the record length
multiplied by the blocking factor yields the block length.
This option is only valid when used with either the -R or
-W mode control options (above). Using this option is only
meaningful if your tape has fixed-length records. This
option is unnecesary when reading an ANSI level 2, 3, or 4
file. The default blocking factor is 1.
-RF format Specify record format. Valid values for 'format' are "F"
(fixed-length records and blocks); "D" (variable-length
records (this is ANSI 'D' format)); "S" (spanned records);
or "U" (undefined record format). The default format is
"F." Note that if you are writing a cartridge tape, only
512 byte blocks may be written; D, S, and U formats are not
supported.
Tape File Identifiers
-FID file_id Specify a 1-17 character file ID to be written in the file
header label for use when writing a file to a labeled
volume. This option is only valid when used with the -W
mode control option (above). If this option is omitted, the
name of the file being written is used.
-F [position]
Specify the file position for -R or -W operations. Valid
values for 'position' are "CUR," "END," or a nonzero
integer value. A position of "CUR" selects the current
tape position; the tape must have been previously read or
written by RWMT and its position must not have been
disturbed. This option is only valid when used with either
the -R or -W mode control options (above).
A position of "END" selects the end of the tape file set.
This option is valid only when used with the -W mode
control option, and causes RWMT to append the specified
disk file ('pathname' argument) to the very end of the tape
file set.
A position specified by a nonzero integer value selects the
file at that absolute position in the tape volume. This
option is only valid when used with either the -R or -W
mode control options (above). If multiple 'pathname'
arguments are supplied, the value of 'position' is
incremented by one after each file has been read or
written.
The default value for 'position' is 1.
Backup Device Control
-DEV d[unit] Specify device type and unit number. 'd' must be either
'M' (for reel-to-reel magnetic tape), 'CT' (for cartridge
tape), or 'F' (for floppy), depending on which drive is
being used. 'unit' is an integer (0-3). Both are required
for reel-to-reel tapes (i.e., -DEV M2). A unit number is
NOT required for floppy disks and cartridge tapes (i.e.,
-DEV F). If this option is omitted, RBAK assumes device
M0.
-RETEN Retension the cartridge tape (unwind to the end, then
rewind). This can be helpful if you have encountered
cartridge tape reading errors. Retensioning requires about
1.5 minutes to complete.
-NRETEN (D) Do not retension the cartridge tape.
Miscellaneous Control Options
-SBIN Cause all stream files written to contain the binary
attribute (normally, output stream files contain the ASCII
attribute).
-P Cause RWMT to prompt for all unspecified parameters.
This command uses the command line parser, and so also accepts the standard
command options listed in HELP CL.
EXAMPLES
1. $ rwmt -label -own "R and D" -vid "demo" Initialize a tape with
the given owner and
volume ID.
2. $ rwmt -w c?*_example -f 1 -rf d -rl 200 -bl 2048 Copy the
32 records of "cmf_example" written to tape file 1. wildcarded
8 records of "cmt_example" written to tape file 2. files to
4 records of "cpboot_example" written to tape file 3. tape.
25 records of "cpf_example" written to tape file 4.
3. $ rwmt -index List the files on the tape.
Volume label:
Volume ID: "DEMO " Owner ID: "R AND D " Access: " "
File/Section File ID Cr Date Acc RF RL BL
1 1 CMF_EXAMPLE 83/02/17 D 200 2048
2 1 CMT_EXAMPLE 83/02/17 D 200 2048
3 1 CPBOOT_EXAMPLE 83/02/17 D 200 2048
4 1 CPF_EXAMPLE 83/02/17 D 200 2048
5 1 CPT_EXAMPLE 83/02/17 D 200 2048
End of file set.
$
4. $ rwmt -r cpboot_example.tape -f 3 Copy tape file 3 to a
4 records read from tape file 3 into disk file named
"cpboot_example.tape". "cpboot_example.tape".
$
5. RAW mode
RWMT permits a tape file to be read in RAW mode. In this mode, each
block read from the tape is written into one record in a stream file,
unmodified by the program. To read a file in RAW mode, you should
specify the maximum record size using the -RL argument. If you do not,
the default value of 80 bytes is used, and any records longer than that
are truncated. Also, undefined record format should be used.
For example:
$ rwmt -r -f 1 -rf u -raw -rl 512 rawfile
reads tape file number 1 into "rawfile", with a maximum record length
of 512 bytes.
Files may be written in the same manner:
$ rwmt -w -f 1 -rf u -raw -rl 512 rawfile
RELATED TOPICS
More information is available. Type:
- HELP RBAK
for details on reading tapes for use only at DOMAIN sites.
- HELP WBAK
for details on writing tapes for use only at DOMAIN sites.
- HELP MEDIA
for general information on removable magnetic media usage and support.