ltf(5)
Name
ltf - labeled tape facility
Description
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:
1.American National Standard Institute magnetic tape labels and file structure for information interchange ANSI X3.27-1978
2.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 ULTRIX 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 ULTRIX-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 ULTRIX 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 an ULTRIX 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 ULTRIX systems and between ULTRIX and non-ULTRIX systems as an import/export facility by providing a means to read/write tapes in a format generally acceptable to most systems providing support of ANSI-labeled 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 non-ULTRIX generated volumes:
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:
"a" Refers to the sets of characters including uppercase (A-Z), numerals (0-9), and special characters (space ! " % & ’ ( ) * + , - _ . / : ; < = > ?).
BLOCK
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.
BLOCK LENGTH
The minimum block size is 18 bytes and the maximum is 20480.
RECORD
A set of related data treated as a unit of information:
TAPE MARK
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 volume is ANSI version 4. The contents of the field in bytes 16 - 50 are for ULTRIX implementation only; thus, if 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 ULTRIX File Status - st_mode returned from a
stat(2) call
4 22 - 25 ULTRIX File Owner ID - uid
4 26 - 29 ULTRIX Owner Group Number - gid
4 30 - 33 ULTRIX Link ID Sequence Number - if file is
hard linked, contains the file sequence number
of the file this file is linked to
3 34 - 36 ULTRIX True File Type - three character
representation of the ULTRIX disk file type
(see below)
1 37 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 38 - 47 ULTRIX File Size - in bytes if known, else
spaces
1 48 ULTRIX ltf Header Number - number of last HDR
containing the full ULTRIX pathname of the
file, digit between 3 and 9
1 49 ULTRIX ltf End of File Header Number -
number of last EOF containing the full ULTRIX
pathname of the file, digit between 3 and 9,
if "0", no path name in EOFs
1 50 ULTRIX 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 51 - 52 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 53 - 80 ANSI reserved (spaces)
The ULTRIX 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
"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
"eng" - English text
"exe" - Executable binary
"for" - Fortran program source
"fuf" - Fortran Unformatted File
"nul" - Null/empty file
"oar" - Old Archive
"pip" - Named pipe
"rof" - roff, nroff, troff, or eqn input text
"soc" - Socket
"sym" - Symbolic Link
"???" - 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 an ULTRIX 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 ULTRIX standard time of last change to file
10 15 - 24 ULTRIX File Owner Name
20 25 - 44 ULTRIX Hostname
36 45 - 80 ULTRIX 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 an ULTRIX 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 ULTRIX 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 ULTRIX 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 an ULTRIX 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 ULTRIX 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