ISO/IEC 13490-2:1995

Information technology — Volume and file structure of read-only and write-once compact disk media for information interchange — Part 2: Volume and file structure

Specifies a format and associated system requirements for volume and file structure for the interchange of information between users of information processing systems using CD-WO, hybrid CD-WO and CD-ROM disks by specifying the attributes of a volume, the relationship among volumes, the attributes of a partition of a volume, the placement of files, the attributes of the files, the relationship among files and file sets, levels of medium interchange and requirements for the processes.

Technologies de l'information — Structure de volume et de fichier de supports disque compact à lecture seule et à écriture unique pour l'échange d'information — Partie 2: Structure de volume et de fichier

General Information

• Status: Published
• Publication Date: 26-Dec-1995
• ICS: 35.220.30 - Optical storage devices
• Technical Committee: ISO/IEC JTC 1 - Information technology
• Drafting Committee: ISO/IEC JTC 1 - Information technology
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 29-Jul-2008

Standards Content (Sample)

OISO/IEC ISOLEC 13490-2: 1995 (E)
[Additional Extended Attribute Areal {
1
< “PD" Extended Attribute>
o+
>
< “CE" extended attribute>O+l
<#OO byte> 0+
Figure 10 - Additional Extended Attribute Area Schema for a Primary Volume Descriptor or a Supplementary Volume
Descriptor or a File Set Descriptor
14.3 Extended attributes specified by this part of ISO/IEC 13490
The extended attributes specified in this part of ISOLIEC 13490 are listed in table 2122.
Table 22 - Extended attributes defined in this part of ISO/IEC 13490
Name Description
Type
1 “CS” Character Set Information (2/15.3.2)
2 “PD” Padding (21153.3)
3 “PM” Altemate Permissions (2/15.3.4)
4 ( ‘RF” Record Structure (2/15.3.5)
File Times (2/15.3.6)
5 “TF’
“TI” Information Times (2/15.3.7)
6
7 “FC” File Contents (2B5.3.8)
8 “CE” Extended Attribute Area Continuation (2115.3.9)
9 “MF” File Section Description Area (2/15.3.10)
10 “UX” ISO 9945-1 File Attributes (2115.3.11)
Previously recorded Directory Record (2/15.3.12)
11 “XR”
2 048 “SU” Implementation Use (2/15.3.13)
65 536 “AU” Application Use (2/15.3.14)
Notes
52 - There need not be any extended attributes associated with a file, directory, Primary Volume Descriptor, Supplementary Volume Descriptor or File Set
Descriptor.
53 - For performante reasons, often used extended attributes should be recorded in the Extended Attribute Area (see 2/14.1) of Directory Records and Path
Table Records, rather than in the Additional Standard Attribute Area (see 2H4.l.i).
54 - The multiple occurrences of attributes of types 2 048 and 65 536, if any, are intended to be distinguished by the contents of their Implementation
Identifier and Application Identifier fields respectively. Such occurrences might have differing contents in some attribute specific fields, such as the
Implementation Use or Application Use fields.
15 Directsry and Feile data structures
151 Wrectory Record
A Directory Record shall be recorded in the format shown in table 2123.
NQTE 55 -- The major differentes between the Directory Record of this part of ISWIEC 13490 and the Directory Record specified in ISQ 9660 are:
-
Mme attxilx~es tan be specified for 3 file.
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ISOAEC 13490-2: 1995 (E) OISOIIEC
-
The file version number is a separate field, permitting easier implementation of file version numbers.
Symbolic links are allowed.
Table 23 - Directory Record
Location of File Section Uint32BOTH (2/8.6)
Uint32BOTH (2/8.6)
Recording Date and Time shorttimestamp(1/7.3.2)
26 Uint8 (1M.l.l)
27 1 Interleave Gap Size Uint8 (1/7.1.1)
28 4 Volume Sequence Number Uintl6BOTH (218.3)
32 1 Length of File Identifier (=L-FI) Uint 8 (1/7.l.l)
33 L FI File Identifier bytes
-
[L-FI+33] LXAA Extended Attribute Area bytes
-
[L XAA+L FI+33] * Padding #OO bytes
- -
File Version Number
[*+L XAA+L-FI+33] 4 UintlGBOTH (218.3)
-
15.1.1 Length of Directory Record (=L-DR) (RBP 0)
This field shall specify the length, in bytes, of the Directory Record.
15.1.2 Location of File Section (RBP 2)
If either the “MF” or “FC” extended attribute exists (see 2/15.1.11), this field shall be set to 0.
If neither the “MF” nor “FC” extended attribute exists, the file shall be recorded in one file section, and this field shall speciry
the logical block number of the logical block at which the first byte of the file section is recorded. The file section of the file
shall be recorded in the volume with the volume sequence number specified in the Volume Sequence Number field.
If the value of this field is #FFFFFFFF, the value of the File Unit Size and Interleave Gap Size fields shall be 0, the Data
Length field shall contain the size of the file, and the file shall be treated as if it consisted of all #00 bytes, and shall not be
recorded.
15.1.3 Data Length (RBP 10)
If the “MF” extended attribute does not exist, the file shall contain only one file section and this field shall specify the length, in
bytes, of the file section.
If the “MF” extended attribute exists, this field shall specify the sum of the lengths, in bytes, of all of the file sections described
by the “MF” extended attribute.
15.1.4 Recording Date and Time (RBP 18)
This field shall specify the date and time of the day when this Directory Record is recorded.
15.1.5 File Flags (RBP 25)
This field shall specify certain characteristics of the file as shown in table 2/24.
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OISO/IEC
ISO/IEC 13490-2:1995 (E)
Table 24 - File Flags interpretation
Bit Interpretation
Existente: If set to ZERO, shall mean that the existente of the file shall be made known to the User. If
set to ONE, shall mean that the existente of the file need not be made known to the User.
Directory: If set to ZERO, shall mean that the Directory Record does not identify a directory (see 2/13).
If set to ONE, shall mean that:
-
the Directory Record identifies a directory.
-
the interpretation of any field in this Directory Record, other than the Length of Directory Record
field and the File Flags field, is not specified by this part of ISO/IEC 13490 (see 2/13.2.1).
- the Associated File, Record, Alias and Multi-Extent bits shall be set to ZERO.
Associated File: If set to ZERO, shall mean that the file is not an associated file (see 2/13.8). If set to
ONE, shall mean that the file is an associated file.
Record: If set to ZERO, shall mean there is no “RF” extended attribute (see 2/15.3.5) for the file. If set
to ONE, shall mean that a “RF” extended attribute is recorded for the file.
Protection: If set to ZERO, there is no “PM” extended attribute (see 205.3.4) for the file. If set to
ONE, shall mean that a “PM” extended attribute is recorded for the file.
Version: This bit shall be set to the same value as the Version bit of the File Flags field (2/15.2.5) of
the Path Table Record identifying the directory in which this Directory Record is recorded. If set to
ZERO, shall mean that this Directory Record shall be interpreted according to 203.1.1 and the
Multi-Extent and Alias bits shall be set to 0. If set to ONE, shall mean that this Directory Record shall
be interpreted according to 20 3.1.2.
Alias: If set to ZERO, shall mean that the file is not an alias file (2/13.9). If set to ONE, shall mean that
the file is an alias file and a pathname (2/13.4) shall be recorded as the contents of the file. If the Alias
bit is ONE, the Version bit shall be ONE, and the Directory bit shall be ZERO.
Multi-Extent: If set to ZERO, shall mean that the file consists of only one file section and there shall be
no “MF” extended attribute for the file. If set to ONE, shall mean that an “MF” extended attribute is
recorded for the file.
15.1.6 File Unit Size (RBP 26)
If the value of this field is 0, the file is recorded in non-interleaved mode (see 2/13.5.1.1.2) and the Interleave Gap Size field
shall be set to 0.
If the value of this field is not 0, the file is recorded in interleaved mode (see 2/13.5.1.1.1). The value of this field shall be the
assigned file unit size for all file sections of the file, and there shall be no “FC” extended attribute recorded for the file.
15.1.7 Interleave Gap Size (RBP 27)
If the value of this field is 0, the file is recorded in non-interleaved mode and the File Unit Size field shall be set to 0.
If the value of this field is not 0, the file is recorded in interleaved mode. The value of this field shall be the assigned interleave
gap size for all file sections of the file, and there shall be no “FC” extended attribute recorded for the file.
151.8 Volume Sequence Number (RBP 28)
If the value of this field is 0, an “MF” extended attibute shall be recorded for the file.
If the value of this field is not 0, there shall be no “MF” extended attribute recorded for the file and this field shall specify the
assigned volume sequence number of the volume in the volume set on which the only file section of the file is recorded.
15.1.9 Length of File Identifier (=L FI) (RBP 32)
-
This field shall specify the length, in bytes, of the File Identifier field of the Directory Record.
15.1.10 File Identifier (RBP 33)
This field shall specify an identification for the file. Except as specified in2/9.5.3, 2/13.1 .1.2 and 2B3.3.3, the contents of this
field shall be d-characters (see 1/7.2).
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OISO/IEC
ISO/IEC 13490-2: 1995 (E)
15.1.11 Extended Attribute Area (RBP [L-FI+33])
This field shall contain an extended attribute area (se 2/14.1).
The first 4 bytes of this field shall be referred to as the Standard Defined Extended Attribute Existente field, shall be recorded
as a .Uint 3 2 (see 1/7.1.5) and shall specify the extended attributes recorded in the Extended Attributes Area field. A bit in the
Standard Defined Extended Attribute Existente field corresponds to a particular extended attribute as shown in table 2/25. If
the bit is ZERO, then that extended attribute shall not be recorded. If the bit is ONE, then that extended attribute shall be
recorded.
Table 25 - Standard Def ’ined Extended Attribute Existente field interpretation
Interpretation
Bit
0 Reserved: shall be set to ZERO
I “CYextended attribute (2W.3.2)
1;
“PD” extended attribute (2/15.3.3)
2
“PM” extended attribute (2115.3.4)
3
“RF” extended attribute (2/15.3.5)
4
“Tl?’ extended attribute (2B5.3.6)
5
6 “TI” extended attribute (2/15.3.7)
7 “FC” extended attribute (2115.3.8)
8 “CE” extended attribute (205.3.9)
“MF” extended attribute (2/15.3.10)
9
“UX” extended attribute (2/15.3.11)
10
11 “XR” extended attribute (2/15.3.12)
12-29 Reserved: Shall be set to ZERO.
30 “SU” extended attribute (2/15.3.13)
“AU” extended attribute (2115.3.14)
31
15.1.12 Padding (RBP [L-XAA+L-FI+33])
This field shall be rem(L XAA+L FI+I, 2) bytes long and all bytes shall be set to #OO.
- -
15.1.13 File Version Number (RBP [*+L-XAA+L-FI+33])
This field shall specify the file version number of the file specified by the File Identifier field as a number in the range 1 to
32 767 inclusive. The numbers 32 768 to 65 535 inclusive are reserved for future Standardisation.
15.2 Path Table Record
A Path Table Record shall be recorded in the format shown in table 2/26.
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OISO/IEC
ISO/IEC 13490-2: 1995 (E)
Table 26 - PatR Table Record
~~~
RBP Length Name
Contents
Length of Path Table Record
0 2 Uintl6 (117.1.3)
(=L-PTR)
8 Location of Directory
2 Uint32BOTH (2B.6)
Data Length
10 8 TJint32BOTH (2B.6)
:j 18.
Recording Date and Time
7 shorttimestamp(1/7.3.2)
25 1 File Flags Uint8 (117.1.1)
26 2 Reserved #OO bytes
Parent Directory Number
28 4 Uint 16BOTH (218.3)
32 1 Length of File Identifier (=L-FI) Uint 8 (1/7.1.1)
L FI File Identifier
33 - bytes
[L-FI+33] LXAA Extended Attribute Area bytes
-
*
[L-XAA+L-FI+33] Padding bytes
/
15.2.1 Length sf Path Table Record (=L-PTR) (RBP 0)
This field shall specify the length, in bytes, of the Path Table Record.
15.2.2 Location of Directory (RBP 2)
This field shall specify the logical block number of the location of the extent in which the directory is recorded.
If the value of the Data Length field is 0, this field shall be set to 0, and the Version bit of the File Hags f ’ield shall be Set to
ONE.
152.3 Data Length (RBP 10)
This. field shall specify the length of the directory (see 2/13.2.1).
If the value of this field is 0, the Location of Extent field shall be set to 0, and the Version bit of the File Flags field shall be set
to ONE.
152.4 Recording Date and Time (RBP 18)
This field shall indicate the date and time of the day when this Path Table Record is recorded.
15.2.5 File Flags (RBP 25)
This f ’ield shall specify certain characteristics of the file as shown in table 2124, with the following restictions:
-
The Directory bit shall be set to ONE.
-
The Associated File, Record, Alias and Multi-Extent bits shall be set to ZERO.
-
If the Version bit is set to ZERO, it shall mean that the directory shall contain only Directory Records with the Version bit
set to ZERO. If the Version bit is set to ONE, it shall mean that the directory shall contain only Directory Records with the
Version bit set to ONE.
15.2.6 Reserved (RBP 26)
This field shall be set to all #OO bytes.
15.2.7 Parent Directory Number (RBP 28)
This field shall specify the directory number (see 2113.3) in the Path Table for the parent directory of the directory.
15.2.8 Length of File Identifier (=L-FI) (RBP 32)
This field shall specify the length, in bytes, of the File Identifier field of the Path Table Record.
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OISO/IEC
ISO/IEC 13490-2: 1995 (E)
15.2.9 File Identifier (RBP 33)
The field shall specify an identification of the directory. Except as specified in 2/9.5.4, 2/13.3 and 2/13.3.4, the contents of this
field shall be d-characters (see 1/7.2).
15.2.10 Extended Attribute Area (RBP [L_FI+33])This field shall contain an extended attribute area (see 2/14.1).
The first 4 bytes of this field shall be referred to as the Standard Defined Extended Attribute Existente field, shall be recorded
as a Uint 3 2 (see U7.1.5) and shall specify the extended attributes recorded in the Extended Attributes Area field. A bit in the
Standard Defined Extended Attribute Existente field corresponds to a particular extended attribute as shown in table 2/25. If
the bit is ZERO, then that extended attribute shall not be recorded. If the bit is ONE, then that extended attribute shall be
recorded.
15.2.11 Padding (RBP [L XAA+L-FI+33])
-
This field shall be rem(L XAA-eL Fi+I, 2) bytes long. If this field is not of zero length, it shall be set to #OO.
- -
15.3 Extended Attributes
In this clause, the terrn ‘kurrent file” shall refer to the file that the extended attribute is associated with.
15.3.1 Extended Attribute format
An extended attribute shall be recorded as a short form extended attribute (see 2/15.3.1.1) if the length, in bytes, of the
extended attribute is less than 255. An extended attribute shall be recorded as a long form extended attribute (see 2/15.3.1.2) if
the length, in bytes, of the extended attribute is greater than or equal to 255.
15.3.1.1 Generic short form Extended Attribute format
The short form extended attribute shall be recorded in the format shown in table 2/27. The specification for each extended
attribute shall specify the interpretation of the Attribute Subtype and Attribute Data fields of the extended attribute.
Table 27 - Generic short form Extended Attribute format
Name
1 RBP 1 Length Conte&
0 0 4 4 Attribute Type Uint32 (1/7.1.5)
4 4 1 1 Attribute Subtype Uint8 (U7.1.1)
5 5 1 1 Attribute Length (=A-L) Uint8 (l/Tl.l)
6 6 A A L-6 L-6 Attribute Data
bytes
- -
ii
L
I
15.3.1.1.1 Attribute Type (RBP 0)
This field shall specify the type of the extended attribute.
15.3.1.1.2 Attribute Subtype (RBP 4)
This field shall specify the subtype of the extended attribute.
15.3.1.1.3 Attribute Length (=A-L) (RBP 5)
This field shall specify the length, in bytes, of the entire extended attribute, and shall be less than 255.
NOTE 56 - It is recommended that the extended attribute length be an integral multiple of 2.
15.3.1.1.4 Attribute Data (RBP 6)
The interpretation of this field shall depend on the value of the Attribute Type field.
- The only meaning for the Attribute Length field (A-L) is the distance in bytes from the sta.rt of the extended attribute to t.he sta.rt of the next, if
NOTE 57
any, extended attribute. The only deduction one tan make is that the amount of attribute specific data is not greater t.han A-L-6. It is recornmended that
extended attributes with variable-sized data record the data length immediately after the Attribute Length field.
Thk scheme ~OWS for arbitrary alignment of the attributes and their data. In partkular, there may be pa&hg bytes between be end of he data for an
attribute and the start of the next attribute. Implernentations arc not required to preserve any attribute alignments.
15.3.1.2 Generic long form Extended Attribute format
The long form extended attribute shall be recorded in the format shown in table 2128. The specification for each extended
attribute shall specify the interpretation of the Attribute Subtype and Attribute Data fields of the extended attribute.
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OISO/IEC ISOAEC 13490-2: 1995 (E)
Table 2$ - Generic long form Extended Attribute format
Name Conte&
Attribute Type üint32 (117.1.5)
x
Attribute Subtype
4 1 Uint 8 (117.1.1)
5 1 Attribute Length Uint 8 (117.1.1) = 255
8 Actual Length (=A-L) Uint32BOTH (218.6)
6
A L-l4 Attribute Data bytes
14
-
15.3.1.2.1 Attribute Type (RBP 0)
This field shall specify the type of the extended attribute.
15.3.1.2.2 Attribute Subtype (RBP 4)
This field shall specify the subtype of the extended attribute.
15.3.1.2.3 Attribute Length (RBP 5)
This field shall specify 255.
15.3.1.2.4 Actual Length (=A L) (RBP 6)
-
This field shall specify the length, in bytes, of the entire extended attribute and shall be greater than, or equal to, 255.
- It is recommended that the extended attribute length be an integral multiple of 2.
NOTE 58
15.3.1.2.5 Attribute Data (RBP 14)
The interpretation of this field shall depend on the value of the Attribute Type field.
NOTE 59 - The only meaning for the Actual Length Geld (A-L) is the distance in bytes from the start of the extended attribute to the start of the next, if any,
It is recommended that extended
extended attribute. The only deduction one tan make is that the amount of attribute specific data is not greater than A-L-14.
attributes with variable-sized data record the data length immediately after the Actual Length field.
This scheme allows for arbitrary alignment of the attributes and their data. In particular, there may be padding bytes between the end of the data for an
attribute and the start of the next attribute. Implernentations are not required to preserve any attribute alignments.
15.3.2 WS” Extended Attribute
The “CS” extended attribute may be used to specify the coded Character sets used in interpreting the contents of the current file.
The “CS” extended attribute shall be recorded as specified in 2115.3.2.1 or 2115.3.2.2.
15.3.2.1 Short “CS” Extended Attribute format
A short form “CS” extended attribute shall be recorded in the format shown in table 2129.
Table 29 - Short CS Extended Attribute format
Contents
RBP Length Name
1
1
4 Attribute Type Uint32 (117.1.5) =
0
Attribute Subtype Uint8 (117.1.1) = 1
4 1
Attribute Length Uint8 (1/7.1.1)
5 1
Escape Sequences Length (=ES-L) Uint32BOTH (218.6)
6 8
Uint 8 (117.1.1)
14 1 Character Set Type
15 ES L Escape Sequences bytes
-
15.3.2.1.1 Attribute Type (RBP 0)
This field shall specify 1.
15.3.2.1.2 Attribute Subtype (RBP 4)
This field shall specify 1. All other values are reserved for future Standardisation.
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ISO/IEC 13490-2: 1995 (E) OISO/IEC
15.3.2.1.3 Attribute Length (RBP 5)
This field shall specify the length, in bytes, of the entire extended attribute.
15.3.2.1.4 Escape Sequences Length (=ES-L) (RBP 6)
This field shall specify the length, in bytes, of the Escape Sequence field.
15.3.2.1.5 Character Set Type (RBP 14)
This field shall specify the Character set type as specified in 117.2.1, except that any information that would be recorded in the
Character Set Information field shall instead be recorded in the Escape Sequence field.
15.3.2.1.6 Escape Sequences (RBP 15)
This field shall specify one or more escape sequences, control sequences or both escape sequences and control sequences
according to ISO/IEC 2022 and ISO/IEC 6429 that designate and implicitly invoke the coded Character sets to be used in
interpreting the contents of the current file in an 8-bit environment according to ISO/IEC 2022 or ISO/IEC 10646-1. These
sequences shall be recorded contiguously from the Start of the field and any unused bytes shall be set to #OO.
15.3.2.2 Long “CS” Extended Attribute format
A lone form “CS” extended attribute shall be recorded in the format shown in table 2130.
Table 30 - Long CS Extended Attribute format
Uint8 (117.1.1) = 1
Uint8 (117.1.1) = 255
Uint32BOTH (218.6)
Escape Sequences Length (=ES-L)
Uint32BOTH (218.6)
Character Set Type
Uint8 (117.1.1)
Escape Sequences
15.3.2.2.1 Attribute Type (RBP 0)
This field shall specify 1.
15.3.2.2.2 Attribute Subtype (RBP 4)
This field shall specify 1. All other values are reserved for future standardisation.
15.3.2.2.3 Attribute Length (RBP 5)
This field shall specify 255.
15.3.2.2.4 Actual Length (RBP 6)
This field shall specify the length, in bytes, of the entire extended attribute.
15.3.2.2.5 Escape Sequences Length (=ES-L) (RBP 14)
This field shall specify the length, in bytes, of the Escape Sequence field.
15.3.2.2.6 Character Set Type (RBP 22)
This field shall specify the Character set type as specified in 117.2.1, except that any information that would be recorded in the
Character Set Information field shall instead be recorded in the Escape Sequence field.
15.3.2.2.7 Escape Sequences (RBP 23)
This field shall specify one or more escape sequences, control sequences or both escape sequences and control sequences
according to ISO/IEC 2022 and ISO/IEC 6429 that designate and implicitly invoke the coded Character sets to be used in
interpreting the contents of the current file in an 8-bit environment according to ISO/IEC 2022 or ISO/IEC 10646-1. These
sequences shall be recorded contiguously from the Start of the field and any unused bytes shall be set to #OO.
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ISO/IEC 13490-2: 1995 (E)
OISO/IEC
15.3.3 “PD” Extended attribute
The “PD” extended attribute may be used to align the first byte of the next extended akbute recorded in one or more of the
extended attribute areas specified in 2114.1 and 2114.2 .
The “PD” extended attribute shall be recorded as specified in 2115.3.3.1 or 2115.3.3.2
15.3.3.1 Short “PD” Extended Attribute format
A short form “PD” extended attribute shall be recorded in the format shown in table 2131.
Table 310 Short PD Extended Attribute format
RBP Length Name Contents
0 4 Attribute Type Uint32 (117.1.5) = 2
4 1 Attribute Subtype Uint8 (117.1.1) = 1
1 Attribute Length (=A-L) Uint 8 (117.1.1)
5
A L-6 Padding bytes
6
-
15.3.3.1.1 Attribute Type (RBP 0)
This field shall specify 2.
15.3.3.1.2 Attribute Subtype (RBP 4)
This field shall specify 1. All other values are reserved for future Standardisation.
15.3.3.1.3 Attribute Length (=A-L) (RBP 5)
This field shall specify the length, in bytes, of the entire extended attribute.
15.3.3.1.4 Padding (RBP 6)
The contents of this field are not specified by this part of ISO/IEC 13490.
15.3.3.2 Long “PD” Extended Attribute format
A lone form “PD” extended attribute shall be recorded in the format shown in table 2132.
Table 32 - Long PD Extended Attribute format
RBP Length Name Conte&
4 Attribute Type Uint32 (117.1.5) = 2
0
Attribute Subtype Uint8 (117.1.1) = 1
4 1
Attribute Length Uint 8 (117.1.1) = 255
5 1
6 8 Actual Length (=A-L) Uint32BOTH (218.6)
14 A L-l4 Padding bytes
-
15.3.3.2.1 Attribute Type (RBP 0)
This field shall specify 2.
15.3.3.2.2 Attribute Subtype (RBP 4)
This field shall specify 1. All other values are reserved for future Standardisation.
15.3.3.2.3 Attribute Length (RBP 5)
This field shall specify 255.
L) (RBP 6)
15.3.3.2.4 Actual Length (=A
-
This field shall specify the length, in bytes, of the entire extended attribute.
15.3.3.2.5 Padding (RBP 14)
The contents of this field are not specified by this part of ISO/IEC 13490.
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ISO/IEC 13490-2: 1995 (E)
OISO/IEC
15.3.4 “PM” Extended Attribute
The “PM” extended attribute specifies fields that tan be used to support the file access permission scheme of ISO 9660 for the
current file. It shall be recorded in the format shown in table 2133.
NOTE 60 - The “PM” extended attribute is an extension of the permissions field in ISO 9660 to allow for the case of writing information. In addition, it
eliminates the inconsistencies of the specification in ISO 9660.
If the user ’s user ID is the same as the Owner Identification field and the user ’s group ID is the same as the Group Identification
field, the user shall be treated as the owner of the file.
Table 33 - PM Extended Attribute format
\
Name
RBP Length Contents
0 4 Attribute Type Uint32 (117.1.5) = 3
4 1 Attribute Subtype Uint8 (ll7.1.1) = 1
5 1 Attribute Length Uintt (117.1.1) = 16
6 4 Owner Identification UintlGBOTH (218.3)
Group Identification UintlGBOTH (218.3)
10 4
Permissions Vint16 (117.1.3)
14 2
15.3.4.1 Attribute Type (RBP 0)
This field shall specify 3.
15.3.4.2 Attribute Subtype (RBP 4)
This field shall specify 1. All other values are reserved for future standardisation.
15.3.4.3 Attribute Length (RBP 5)
This fierd shall specify 16.
15.3.4.4 Owner Identification (RBP 6)
This field shall specify as a 16-bit number an identification of the owner of the file who is a member of the group identified by
the Group Identification field of this extended attribute
If the number in this field is 0, this shall indicate that there is no owner identification specified for the file. In this case, the
Group Identification field shall be set to 0.
15.3.4.5 Group Identification (RBP 10)
This field shall specify as a 16-bit number an identification of the group of which the owner of the file is a member.
For this number, values from 1 to a value subject to agreement between the originator and recipient of the medium shall identify
the group as belonging to the class of user referred to as System.
If the number in this field is 0, this shall indicate that there is no group identification specified for the file. In this case, the
Ownes Idti,ntification field shall be set to 0.
15.3.4.6 Permissions (RBP 14)
This field shall specify, for certain classes of users, if read, write, execute, and delete access is allowed for the file. The desired
access shall be given if at least one of the following conditions is true:
-
the user ’s user ID is the same as the Owner Identification field and the user ’s group ID is the same as the Group
Identification field and bits 4-7 allow the desired access;
- bits 12-15 allow the desired access;
-
the user ’s group ID is the same as the Group Identification field and bits 8-l 1 allow the desired access;
-
if the user ’s group ID identifies a group of the System class of user and bits O-3 allow the desired access.
The allowed access is shown in table 2134.
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OISO/IEC
ISO/IEC 13490-2: 1995 (E)
Table 34 - Allowed access
Bit Interpretation
If set to ZERO, shall mean that a user who is a member of a group of the System class of user may read
0
the file. If set to ONE, shall mean that read access is not allowed by this bit.
1 If set to ZERO, shall mean that a user who is a member of a group of the System class of user may
write the file. If set to ONE, shall mean that write access is not allowed by this bit.
2 If set to ZERO, shall mean that a user who is a member of a group of the System class of user may
execute the file. If set to ONE, shall mean that execute access is not allowed by this bit.
If set to ZERO, shall mean that a User who is a member of a group of the System class of user may
delete the file. If set to ONE, shall mean that delete access is not allowed by this bit.
If set to ZERO, shall mean that the owner may read the file. If set to ONE, shall mean that read access
is not allowed by this bit.
If set to ZERO, shall mean that the owner may write the file. If set to ONE, shall mean that write
access is not allowed by this bit.
If set to ZERO, shall man that the owner may execute the file. If set to ONE, shall mean that execute
access is not allowed by this bit.
7 If set to ZER:), shall mean that the owner may delete the file. If set to ONE, shall mean that delete
access is not akwed by this bit.
8 If set to ZERO, shall mean that any user who has a group ID that is the sarre as the Group Identification
field may read the file. If set to OK E, shall mean that read access is not allowed by this bit.
9 If set to ZERO, shall mean that any User who has a group ID that is thc same as the Group Identification
field may write the file. If set to ONE, shall mean that write access is not allowed by this bit.
10 If set to ZERO, shall mean that any user who has a group ID that is the Same as the Group Identification
field may execute t-he file. If set to ONE, shall mean that execute access is not allowed by this bit.
11 If set to ZERO, shall mean that any user who has a group ID that is the same as the Group Identification
field may delete the file. If set to ONE, shall mean that delete access is not allowed by this bit.
12 If set to ZERO, shall mean that any ii w may read the file. If set to ONE, shall mean that read access is
not allowed by this bit.
If set to ZERO, shall mean that any user may write the file. If set to ONE, shalt mean that write access
13
is not allowed by this bit.
14 If set to ZERO, shall mean that any user may execute the file. If set to ONE, shall mean that execute
access is not allowed by this bit.
15 If set to ZERO. shall mean that any user may delete the file. If set to ONE, shall mean that delete
access is not allowed by this bit.
IDs and group IDs
NOTE 61 - File access schemes are subject !o agreement between the or
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