here - OSTA - Optical Storage Technology Association

For operating systems that do not support the concept of a group identifier
the implementation shall set this field to 2 32 - 1 to indicate an invalid GID,
unless otherwise specified by the user.
3.3.3.3 Uint32 Permissions
/* Definitions: */
/* Bit for a File for a Directory */
/* ------- ------------------------ ---------------------------- */
/* Execute May execute file May search directory */
/* Write May change file contents May create and delete files */
/* Read May examine file contents May list files in directory */
/* ChAttr May change file attributes May change dir attributes */
/* Delete May delete file May delete directory */
#define OTHER_Execute 0x00000001
#define OTHER_Write 0x00000002
#define OTHER_Read 0x00000004
#define OTHER_ChAttr 0x00000008
#define OTHER_Delete 0x00000010
#define GROUP_Execute 0x00000020
#define GROUP_Write 0x00000040
#define GROUP_Read 0x00000080
#define GROUP_ChAttr 0x00000100
#define GROUP_Delete 0x00000200
#define OWNER_Execute 0x00000400
#define OWNER_Write 0x00000800
#define OWNER_Read 0x00001000
#define OWNER_ChAttr 0x00002000
#define OWNER_Delete 0x00004000
The concept of permissions that deals with security is not completely portable
between operating systems. This document attempts to maintain consistency
among implementations in processing the permission bits by addressing the
following basic issues:
1. How should an implementation handle Owner, Group and Other
permissions when the operating system has no concept of User and
Group Ids?
2. How should an implementation process permission bits when
encountered, specifically permission bits that do not directly map to an
operating system supported permission bit?
3. What default values should be used for permission bits that do not
directly map to an operating system supported permission bit when
creating a new file?
Owner, Group and Other
In general, for operating systems that do not support User and Group Ids the
following algorithm should be used when processing permission bits:
When reading a specific permission, the logical OR of all three (owner,
group, other) permissions should be the value checked. For example a file
UDF 2.01
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