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ltf(4) Kernel Interfaces Manual ltf(4) 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: 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 DIGITAL 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 DIGITAL UNIX labeled tapes are simply based on the standards and formats re- ferred to, and described in, the publications/documents listed previ- ously. The ltf attempts to follow these documents as working precepts as accu- rately as it can, while meeting the needs of DIGITAL 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 DIGITAL 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 be- tween DIGITAL UNIX systems and between DIGITAL UNIX systems and systems other than DIGITAL 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 ANSI-labeled tapes. It is not a goal of ltf to provide the multivolume file sets or to pro- vide 100% of the ANSI specifications for the following labels on non- Digital UNIX 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 en- closed in parentheses () indicate optional fields that may be present according to the ANSI standard. The following terms are used as indi- cated: Refers to the sets of characters including uppercase (A-Z), nu- merals (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 permit- ted 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 Sec- ond 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 Iden- tifier - user specifiable "a" characters, default = "ULTRIX" 1 11 Accessi- bility 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 Iden- tifier - user specifiable "a" characters, default = "ULTRIX" 1 11 Accessi- bility 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. In- formation 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 - In- terchange 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 Num- ber - "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 Implementa- tion 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 Digital 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 DIGITAL UNIX File Status - st_mode returned from a stat(2) call 4 22 - 25 DIGITAL UNIX File Owner ID - uid 4 26 - 29 DIGITAL UNIX Owner Group Number - gid 4 30 - 33 DIGITAL UNIX 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 DIG- ITAL UNIX True File Type - three character representation of the DIGITAL UNIX 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 DIGITAL UNIX File Size - in bytes if known, else spaces 1 48 DIGITAL UNIX ltf Header Number - number of last HDR containing the full DIGITAL UNIX pathname of the file, digit between 3 and 9 1 49 DIGITAL UNIX ltf End of File Header Number - number of last EOF containing the full DIGITAL UNIX pathname of the file, digit between 3 and 9, if "0", no path name in EOFs 1 50 DIGITAL 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 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 DIGITAL 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 Unformat- ted 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" - TAC- TIS (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 DIGITAL UNIX system. Content limited to "a" char- acters 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 DIGITAL UNIX standard time of last change to file 10 15 - 24 DIGITAL UNIX File Owner Name 20 25 - 44 DIGITAL UNIX Hostname 36 45 - 80 DIGI- TAL 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 DIGITAL UNIX system. Con- tent 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 DIGITAL 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 con- tent is ignored. Size First & Description of Last Field Byte # or Content ----- ------- ----------- 3 1 - 3 "UHL" 1 4 any valid "a" character identify- ing 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 DIGITAL UNIX implementation of ltf does not support multivolume file sets and there- fore 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 la- bel 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 Con- tent ----- ------- ----------- 3 1 - 3 "EOV" 1 4 "1" 50 5 - 54 same as cor- responding 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 con- tents 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 cor- responding 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 cor- responding 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 con- tents 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 cor- responding 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 frac- tional 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 DIGITAL 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 DIGITAL 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 identify- ing this label 76 5 - 80 Application Dependent RELATED INFORMATION ltf(1) delim off ltf(4)