ltf - labeled tape facility
The term ltf (Labeled Tape Facility) refers to the group
of programs required to fulfill the features and functionality
outlined here.
References for the substance of this document are based
on: American National Standard Institute magnetic tape
labels and file structure for information interchange ANSI
X3.27-1978 The document/working paper: Draft Proposed
Revision to ANSI X3.27-1978, Public Review Comment on ANSI
X3L5/83-28T 15-Oct-84 (describes the version 4 ANSI standard)
This proposed implementation of the ltf does not claim to
be 100% ANSI standard in all cases. That is, the Tru64
UNIX ltf does not support the entirety of the functionality
or format capabilities outlined in the documents/publications
cited as references.
It should be understood that the functionality and formats
for Tru64 UNIX labeled tapes are simply based on the standards
and formats referred to, and described in, the publications/documents
listed previously.
The ltf attempts to follow these documents as working precepts
as accurately as it can, while meeting the needs of
Tru64 UNIX systems.
It should be further understood that where the cited documents
specify procedures or operational constricts that
would conflict with those features/functionality normally
found in a Tru64 UNIX system, the procedures or operational
constricts, by necessity, have been omitted from
the ltf implementation.
The goals of ltf are to create an accurate exchange of
information between Tru64 UNIX systems and between Tru64
UNIX systems and systems other than Tru64 UNIX as an
import/export facility by providing a means to read/write
tapes in a format generally
acceptable to most systems providing support of ANSIlabeled
tapes.
It is not a goal of ltf to provide the multivolume file
sets or to provide 100% of the ANSI specifications for the
following labels on volumes generated by other operating
systems: VOL1
Accessibility Field VOL2 - VOL9 UVL1 - UVL9 (User Volume
Labels) HDR1, EOV1, EOF1
File-set Identifier
Expiration Date
Accessibility Field
Block Count HDR2
Buffer Offset Content HDR3 - HDR9 UHL1 - UHL9 (User
Header Labels) EOV3 - EOV9 (End of Volume Labels) EOF3 -
EOF9 (End of File Labels) ULT1 - UTL9 (User Trailer
Labels)
The FORMATS section provides the general ANSI volume and
label formats. Each label consists of 80 bytes of ASCII
data as specified. Items enclosed in parentheses () indicate
optional fields that may be present according to the
ANSI standard. The following terms are used as indicated:
Refers to the sets of characters including uppercase (AZ),
numerals (0-9), and special characters (space ! " % &
' ( ) * + , - _ . / : ; < = > ?). A group of consecutive
bytes of data treated as a unit by the storage medium.
Blocks are separated by an interblock gap. A block may
contain part of a record, all of the record, or many
records. The minimum block size is 18 bytes and the maximum
is 20480. A set of related data treated as a unit of
information. A control block used as a delimiter.
FORMATS for ANSI VERSION 3/4 - MULTI-FILE / SINGLE VOLUME
bot Beginning of tape marker VOL1 Volume Label
(only 1 permitted for ANSI version 3,
ANSI version 4 OPTIONALLY permits Volume Labels
2 through 9) (UVLn) OPTIONAL User Volume labels
('n' varies from 1 - 9) HDR1 First File Header Label
HDR2 Second File Header Label (HDRn) OPTIONAL File
Header Labels ('n' varies from 3 - 9) (UHLa) OPTIONAL
User File Header Labels (quantity
unspecified) tm Tape Mark DATA data
blocks of first file tm Tape Mark EOF1 First End
of File Label EOF2 Second End of File Label (EOFn)
OPTIONAL End of File Labels ('n' varies from 3 - 9) (UTLn)
OPTIONAL User Trailer Labels tm Tape Mark
HDR1 First File Header Label HDR2 Second File
Header Label (HDRn) OPTIONAL File Header Labels ('n'
varies from 3 - 9) (UHLa) OPTIONAL User File Header
Labels (number undefined) tm Tape Mark DATA data
blocks of second file tm Tape Mark EOF1 First
End of File Label EOF2 Second End of File Label (EOFn)
OPTIONAL End of File Labels ('n' varies from 3 - 9) (UTLn)
OPTIONAL User Trailer Labels tm Tape Mark
HDR1 First File Header Label
.
.
. tm Tape Mark tm Tape Mark
VOL1 - Label Format - ANSI VERSION 3
The following table identifies the volume and supplies
volume security information: Size First & Description
of Last Field Byte # or Content ----- -------
-----------
3 1 - 3 "VOL" 1 4 "1" 6 5 - 10
Volume Identifier - user specifiable "a"
characters, default = "ULTRIX" 1 11
Accessibility Field - not implemented by ltf 26 12 -
37 Reserved by ANSI (spaces) 14 38 - 51 Owner ID -
user defined "a" characters,
default = spaces 28 52 - 79 Reserved
by ANSI (spaces) 1 80 Label Standard Version, 3
for ANSI Version 3
VOL1 - Label Format - ANSI VERSION 4
The following table identifies the volume and supplies
volume security information: Size First & Description
of Last Field Byte # or Content ----- -------
-----------
3 1 - 3 "VOL" 1 4 "1" 6 5 - 10
Volume Identifier - user specifiable "a"
characters, default = "ULTRIX" 1 11
Accessibility Field - not implemented by ltf 13 12 -
24 Reserved by ANSI (spaces) 13 25 - 37 Implementation
ID - "a" characters, ULTRIX
default = "DECULTRIXnnnn", where nnnn are
digits from 0000 to 9999, identifying the
version number of ltf which created volume
14 38 - 51 Owner ID - user defined "a" characters,
default = spaces 28 52 - 79 Reserved
by ANSI (spaces) 1 80 Label Standard Version, 4
for ANSI Version 4
HDR1 - Label Format - ANSI VERSION 3/4
The following file header label identifies and describes
the file. Information in this label is limited to "a"
characters only: Size First & Description of Last
Field Byte # or Content ----- ------- -----------
3 1 - 3 "HDR" 1 4 "1" 17 5 - 21
File ID - Interchange file name, "a"
characters 6 22 - 27 File Set ID -
"000001" since only one
file set on single volume 4 28 - 31
File Section Number - "0001" 4 32 - 35 File Sequence
Number - starts at "0001"
and increments once for each file on volume
4 36 - 39 Generation Number - "0001" 2 40 -
41 Generation Version Number - "00" 6 42 - 47 Creation
Date - Julian date, first character
denotes century, " " = 1900, "0" = 2000 6
48 - 53 Expiration Date - Julian date, not implemented
by ltf, set to " 99366" 1 54
File Security - " " 6 55 - 60 Block Count - "000000"
13 61 - 73 Implementation ID - same as in VOL1 7
74 - 80 Reserved by ANSI (spaces)
HDR2 - Label Format - ANSI VERSION 3/4
File header label describes the record format, maximum
record size, and maximum block length of the file. Information
in this label is limited to "a" characters, except
for the content of bytes 16 through 50 if the volume is
ANSI version 4. The contents of the field in bytes 16 -
50 are for a Tru64 UNIX system implementation only; thus,
if the volume is not "ULTRIX", these fields are ignored.
Size First & Description of Last Field Byte # or
Content ----- ------- -----------
3 1 - 3 "HDR" 1 4 "2" 1 5
Record Format - "F" = fixed length records
"D" = variable length
records
"S" = segmented records 5
6 - 10 Block Length - default = "02048" 5 11 - 15
Record Length - "F" format, length of each data
record
"D" format, maximum length
of a
data record including
record
control word
"S" format, maximum length
of a
data record not including
the
segment control word, if
scw =
"00000", maximum record
length
may exceed 99999 bytes 6
16 - 21 Tru64 UNIX File Status - st_mode returned from a
stat(2) call 10 22 - 31 Tru64 UNIX
File Owner ID - uid 10 32 - 41 Tru64 UNIX Owner Group
Number - gid 4 42 - 45 Tru64 UNIX Link ID Sequence
Number - if file is
hard linked, contains the file sequence
number
of the file this file is linked to 3
46 - 48 Tru64 UNIX True File Type - three character
representation of the Tru64 UNIX disk file
type
(see below) 1 49 Carriage Control
- "A" = first byte of record
contains FORTRAN carriage control character
"M" = record contains
all
required forms control
" " = (space) insert
carriage
return, and line feed
between
records 10 50 - 59
Tru64 UNIX File Size - in bytes if known, else
spaces 1 60 Tru64 UNIX ltf
Header Number - number of last HDR
containing the full Tru64 UNIX pathname of
the
file, digit between 3 and 9 1 61
Tru64 UNIX ltf End of File Header Number -
number of last EOF containing the full
Tru64 UNIX
pathname of the file, digit between 3 and
9,
if "0", no path name in EOFs 1 62
Tru64 UNIX Hard Link Flag - necessary when the file
linked to has not been put on the volume,
thus
this flag is used for forward references,
"0" =
no links or symbolic link, "1" = hard
links 2 63 - 64 Buffer Offset - number of bytes of
Buffer
Offset Field, which is the first record in
the data block, if the Buffer Offset is
greater
than zero, not implemented by ltf and set
to "00" 28 65 - 92 ANSI reserved (spaces)
The Tru64 UNIX disk file type is described in field 34-36
of HDR2. The following list contains the 3-character representations
you can use to specify the disk file type:
"adf" - ASCII data file "asc" - ASCII text "arc"
- Archive "arl" - Archive Random Library "asm" -
Assembly language text "bg5" - Big-5 text file "bin"
- Binary data "bsp" - Block special file "cc " -
'C' program text "cmp" - Compressed text file "com"
- Command text file "cpi" - CPIO file "csp" -
Character special file "dir" - Directory "eJP" -
Japanese EUC text file "eKR" - Korean EUC text file
"eng" - English text "eTW" - Taiwanese EUC text
file "exe" - Executable binary "for" - Fortran
program source "fuf" - Fortran Unformatted File "hyu"
- DEC Hanyu text file "hzi" - DEC Hanzi text file
"knj" - DEC Kanji text file "kor" - DEC Korean
text file "mbT" - Multibyte text file "nul" -
Null/empty file "oar" - Old Archive "pip" - Named
pipe "rof" - roff, nroff, troff, or eqn input text
"sbT" - Single-byte text file "skj" - Super DEC
Kanji text file "soc" - Socket "sym" - Symbolic
Link "ISO" - ISO 8859-1 text file "SJS" - Shift
JIS text file "TTS" - TACTIS (Thai) text file "???"
- Content of file not determined
HDR3 - Label Format - ANSI VERSION 3/4
OPTIONAL file header label presence and content ignored if
the volume was not created by a Tru64 UNIX system. Content
limited to "a" characters if VOL1 field 80 = "3".
Embedded spaces in the path names are not permitted. Size
First & Description of Last Field Byte # or Content
----- ------- -----------
3 1 - 3 "HDR" 1 4 "3" 10 5 - 14
Tru64 UNIX standard time of last change to file 10 15
- 24 Tru64 UNIX File Owner Name 20 25 - 44 Tru64
UNIX Hostname 36 45 - 80 Tru64 UNIX File Path Name -
first 36 characters
HDR4 through HDR9 - Label Format - ANSI VERSION 3/4
OPTIONAL file header label used by the ltf to express some
fractional component of the file's complete path name, but
presence and content ignored if the volume was not created
by a Tru64 UNIX system. Content limited to "a" characters
if VOL1 field 80 = "3". Size First & Description of
Last Field Byte # or Content ----- -------
-----------
3 1 - 3 "HDR" 1 4 "4" - "9" 76 5 -
80 Tru64 UNIX File Path Name - continuation from
previous HDR, left justified and padded
with
blanks if needed
BUHLa - Label Format - ANSI VERSION 3/4
OPTIONAL User File Header Labels not supported by the ltf.
They are not output and, if present on an input volume,
their presence and content is ignored. Size First &
Description of Last Field Byte # or Content -----
------- -----------
3 1 - 3 "UHL" 1 4 any valid "a" character
identifying this label 76 5 - 80 Application
Dependent
EOV1 - Label Format - ANSI VERSION 3/4
First End-Of-Volume label that, if read before the first
End Of File label (EOF1), indicates that the file is continued
on the next volume. For valid hardware and
software technical limitations, the Tru64 UNIX implementation
of ltf does not support multivolume file sets and
therefore does not output these labels. If present on an
input volume, they are interpreted as indicating an error
condition, due to the fact that some portion of the file
will not be processed. The fields of this label are identical
to the contents of the corresponding fields in the
First File Header Label (HDR1), with the exceptions noted
below. The following diagrams of EOV labels are intended
for reference purposes only. Size First & Description
of Last Field Byte # or Content ----- -------
-----------
3 1 - 3 "EOV" 1 4 "1" 50 5 - 54
same as corresponding fields in HDR1 6 55 - 60 Block
Count - number of blocks in which the
file was recorded 20 61 - 80 same as
corresponding fields in HDR1
EOV2 - Label Format - ANSI VERSION 3/4
The fields of the Second End-Of-Volume label are identical
to the contents of the corresponding fields in the Second
File Header Label (HDR2), with the exceptions noted. The
ltf does not support the use of EOV labels. See the previous
description for EOV1. OPTIONAL End-Of-Volume labels 3
through 9 (EOV3 - EOV9) are not used by the ltf. If present
on an input volume, their presence and content are
ignored by the ltf. See NOTES for EOV1. Size First &
Description of Last Field Byte # or Content -----
------- -----------
3 1 - 3 "EOV" 1 4 "2" 76 5 - 80
same as corresponding fields in HDR2
EOF1 - Label Format - ANSI VERSION 3/4
The fields of the First End-Of-File label are identical to
the contents of the corresponding fields in the First File
Header Label (HDR1), with the exceptions noted. Size
First & Description of Last Field Byte # or Content
----- ------- -----------
3 1 - 3 "EOF" 1 4 "1" 50 5 - 54
same as corresponding fields in HDR1 6 55 - 60 Block
Count - number of blocks in which the
file was recorded 20 61 - 80 same as
corresponding fields in HDR1
EOF2 - Label Format - ANSI VERSION 3/4
The fields of the Second End-Of-File label are identical
to the contents of the corresponding fields in the Second
File Header Label (HDR2). Size First & Description of
Last Field Byte # or Content ----- -------
-----------
3 1 - 3 "EOF" 1 4 "2" 76 5 - 80
same as corresponding fields in HDR2
EOF3 through EOF9 - Label Format - ANSI VERSION 3/4
OPTIONAL ANSI end-of-file labels used by the ltf to
express some fractional component of the file's complete
path name. The presence and content of these labels are
ignored if the volume was not created by a Tru64 UNIX
system. Content limited to "a" characters if VOL1 field
80 = "3". Size First & Description of Last Field
Byte # or Content ----- ------- -----------
3 1 - 3 "EOF" 1 4 "3" - "9" 76 5 -
80 Tru64 UNIX File Path Name - continuation from
HDR9 and previous EOF, left justified and
padded with blanks if needed
UTLa through UTLa - Label Format - ANSI VERSION 3/4
OPTIONAL User File Trailer Labels Set is optional. If
present on an input volume, it is ignored by the ltf.
User File Trailer Labels are not output by the ltf. If
present, they take the form described. Their use is
application dependent but not supported by the ltf. Size
First & Description of Last Field Byte # or Content
----- ------- -----------
3 1 - 3 "UTL" 1 4 any valid "a" character
identifying this label 76 5 - 80 Application
Dependent
ltf(1)
delim off
ltf(4)
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