ISO/IEC PRF 23360-1-2

Linux Standard Base (LSB)

Noyau de base normalisé Linux (LSB)

General Information

• Status: Published
• ICS: 35.080 - Software
• Technical Committee: ISO/IEC JTC 1/SC 22 - Programming languages, their environments and system software interfaces
• Drafting Committee: ISO/IEC JTC 1/SC 22/WG 24 - Linux

RELATIONS

• Revised: ISO/IEC 23360-1:2006 - Linux Standard Base (LSB) core specification 3.1
• Effective Date: 23-Apr-2020

Standards Content (sample)

INTERNATIONAL ISO/IEC
STANDARD 23360-1-2
First edition
2021-08
Linux Standard Base (LSB) —
Part 1-2:
Core specification generic part
Reference number
ISO/IEC 23360-1-2:2021(E)
ISO/IEC 2021
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ISO/IEC 23360-1-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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ii © ISO/IEC 2021 – All rights reserved
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ISO/IEC 23360-1-2:2021(E)
Foreword

ISO (the International Organization for Standardization) and IEC (the International Electrotechnical

Commission) form the specialized system for worldwide standardization. National bodies that are

members of ISO or IEC participate in the development of International Standards through technical

committees established by the respective organization to deal with particular fields of technical activity.

ISO and IEC technical committees collaborate in fields of mutual interest. Other international

organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the

work.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of document should be noted (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details

of any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC list of patent

declarations received (see patents.iec.ch).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the World

Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT),

see www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.

This document was prepared by the Linux Foundation [as Linux Standard Base (LSB): Core specification

generic part] and drafted in accordance with its editorial rules. It was assigned to Joint Technical

Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 22, Programming languages, their

environments and system software interfaces, and adopted by National Bodies.

This first edition of ISO/IEC 23360-1-2 cancels and replaces ISO/IEC 23360-1:2006, which has been

technically revised.

A list of all parts in the ISO/IEC 23660 series can be found on the ISO and IEC websites.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html and www.iec.ch/national-

committees.
© ISO/IEC 2021 – All rights reserved iii
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ISO/IEC 23360-1-2:2021(E)
Contents

Foreword ...................................................................................................................................................... iii

Introduction ................................................................................................................................................ vii

I Introductory Elements ............................................................................................................................. 1

1 Scope ................................................................................................................................................................ 2

2 References ...................................................................................................................................................... 3

2.1 Normative References ........................................................................................................................ 3

2.2 Informative References/Bibliography......................................................................................... 5

3 Requirements ............................................................................................................................................... 8

3.1 Relevant Libraries ................................................................................................................................ 8

3.2 LSB Implementation Conformance............................................................................................... 8

3.3 LSB Application Conformance ...................................................................................................... 10

4 Terms and Definitions ............................................................................................................................ 11

5 Documentation Conventions ............................................................................................................... 13

6 Relationship To ISO/IEC 9945 POSIX .............................................................................................. 14

7 Relationship To Other Linux Foundation Specifications ......................................................... 15

II Executable And Linking Format (ELF) ............................................................................................ 16

8 Introduction ................................................................................................................................................ 17

9 Low Level System Information ........................................................................................................... 18

9.1 Operating System Interface ............................................................................................................ 18

9.2 Machine Interface ............................................................................................................................... 18

10 Object Format ............................................................................................................................................. 19

10.1 Object Files ......................................................................................................................................... 19

10.2 Sections ................................................................................................................................................ 19

10.3 Special Sections ................................................................................................................................ 23

10.4 Symbol Mapping ............................................................................................................................... 29

10.5 DWARF Extensions .......................................................................................................................... 29

10.6 Exception Frames ............................................................................................................................ 31

10.7 Symbol Versioning ........................................................................................................................... 36

10.8 ABI note tag ........................................................................................................................................ 40

11 Dynamic Linking ....................................................................................................................................... 41

11.1 Program Loading and Dynamic Linking ................................................................................ 41

11.2 Program Header ............................................................................................................................... 41

11.3 Dynamic Entries ............................................................................................................................... 41

12 C++ Class Representations ................................................................................................................... 46

12.1 C++ Data Representation.............................................................................................................. 46

13 Symbol Mapping ........................................................................................................................................ 50

13.1 Symbol Mapping ............................................................................................................................... 50

III Base Libraries ........................................................................................................................................ 51

14 Base Libraries ............................................................................................................................................. 52

14.1 Introduction ....................................................................................................................................... 52

14.2 Program Interpreter ....................................................................................................................... 52

14.3 Interfaces for libc ............................................................................................................................. 52

14.4 Data Definitions for libc ................................................................................................................ 73

14.5 Interface Definitions for libc .................................................................................................... 180

14.6 Interfaces for libm ........................................................................................................................ 393

14.7 Data Definitions for libm ........................................................................................................... 397

14.8 Interface Definitions for libm .................................................................................................. 403

14.9 Interfaces for libpthread ............................................................................................................ 428

14.10 Data Definitions for libpthread ............................................................................................ 434

14.11 Interface Definitions for libpthread ................................................................................... 439

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ISO/IEC 23360-1-2:2021(E)

14.12 Interfaces for libgcc_s ............................................................................................................... 444

14.13 Data Definitions for libgcc_s .................................................................................................. 445

14.14 Interface Definitions for libgcc_s ......................................................................................... 446

14.15 Interfaces for libdl ..................................................................................................................... 452

14.16 Data Definitions for libdl......................................................................................................... 453

14.17 Interface Definitions for libdl ............................................................................................... 454

14.18 Interfaces for librt ...................................................................................................................... 457

14.19 Data Definitions for librt ......................................................................................................... 459

14.20 Interfaces for libcrypt .............................................................................................................. 461

14.21 Data Definitions for libcrypt.................................................................................................. 462

14.22 Interface Definitions for libcrypt ........................................................................................ 462

14.23 Interfaces for libpam ................................................................................................................ 464

14.24 Data Definitions for libpam ................................................................................................... 465

14.25 Interface Definitions for libpam .......................................................................................... 467

IV Utility Libraries .................................................................................................................................. 481

15 Utility Libraries ....................................................................................................................................... 482

15.1 Introduction .................................................................................................................................... 482

15.2 Interfaces for libz .......................................................................................................................... 482

15.3 Data Definitions for libz ............................................................................................................. 483

15.4 Interface Definitions for libz .................................................................................................... 486

15.5 Interfaces for libncurses ............................................................................................................ 533

15.6 Data Definitions for libncurses ............................................................................................... 538

15.7 Interface Definitions for libncurses ...................................................................................... 546

15.8 Interfaces for libncursesw ........................................................................................................ 554

15.9 Data Definitions for libncursesw ........................................................................................... 560

15.10 Interface Definitions for libncursesw ............................................................................... 587

15.11 Interfaces for libutil .................................................................................................................. 587

15.12 Data Definitions for libutil ..................................................................................................... 588

15.13 Interface Definitions for libutil ............................................................................................ 588

V C++ Libraries ......................................................................................................................................... 594

16 Libraries ..................................................................................................................................................... 595

16.1 Interfaces for libstdcxx ............................................................................................................... 595

16.2 Interface Definitions for libstdcxx ......................................................................................... 850

VI Commands and Utilities .................................................................................................................. 851

17 Commands and Utilities ...................................................................................................................... 852

17.1 Commands and Utilities ............................................................................................................. 852

17.2 Command Behavior ..................................................................................................................... 853

VII Execution Environment ................................................................................................................. 917

18 File System Hierarchy .......................................................................................................................... 918

18.1 /dev: Device Files ......................................................................................................................... 918

18.2 /etc: Host-specific system configuration ............................................................................ 918

18.3 User Accounting Databases ...................................................................................................... 920

18.4 Path For System Administration Utilities ........................................................................... 920

19 Additional Recommendations .......................................................................................................... 921

19.1 Recommendations for applications on ownership and permissions ................. 921

20 Additional Behaviors ............................................................................................................................ 923

20.1 Mandatory Optional Behaviors............................................................................................... 923

20.2 Optional Mandatory Behaviors............................................................................................... 924

20.3 Executable Scripts ........................................................................................................................ 924

21 Localization .............................................................................................................................................. 926

21.1 Introduction .................................................................................................................................... 926

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ISO/IEC 23360-1-2:2021(E)

21.2 Regular Expressions .................................................................................................................... 926

21.3 Pattern Matching Notation ....................................................................................................... 926

VIII System Initialization ...................................................................................................................... 928

22 System Initialization ............................................................................................................................. 929

22.1 Cron Jobs ........................................................................................................................................... 929

22.2 Init Script Actions ......................................................................................................................... 930

22.3 Comment Conventions for Init Scripts ................................................................................ 932

22.4 Installation and Removal of Init Scripts.............................................................................. 934

22.5 Run Levels ........................................................................................................................................ 935

22.6 Facility Names ................................................................................................................................ 935

22.7 Script Names ................................................................................................................................... 936

22.8 Init Script Functions .................................................................................................................... 936

IX Users & Groups ................................................................................................................................... 939

23 Users & Groups ....................................................................................................................................... 940

23.1 User and Group Database .......................................................................................................... 940

23.2 User & Group Names ................................................................................................................... 940

23.3 User ID Ranges ............................................................................................................................... 941

23.4 Rationale ........................................................................................................................................... 941

X Network Security Services ............................................................................................................... 942

24 Libraries ..................................................................................................................................................... 943

24.1 Interfaces for libnspr4 ................................................................................................................ 943

24.2 Data Definitions for libnspr4 ................................................................................................... 945

24.3 Interfaces for libnss3 ................................................................................................................... 955

24.4 Data Definitions for libnss3 ...................................................................................................... 956

24.5 Interfaces for libssl3 .................................................................................................................... 979

24.6 Data Definitions for libssl3 ....................................................................................................... 980

XI Package Format and Installation ................................................................................................. 990

25 Software Installation ............................................................................................................................ 991

25.1 Introduction .................................................................................................................................... 991

25.2 Package File Format ..................................................................................................................... 991

25.3 Package Script Restrictions ................................................................................................... 1011

25.4 Package Tools .............................................................................................................................. 1011

25.5 Package Naming Conventions .............................................................................................. 1011

25.6 Package Dependencies ............................................................................................................ 1012

25.7 Package Architecture Considerations ............................................................................... 1013

Annex A Alphabetical Listing of Interfaces by Library ............................................................ 1014

A.1 libc ................................................................................................................................................................ 1014

A.2 libcrypt ....................................................................................................................................................... 1029

A.3 libdl .............................................................................................................................................................. 1029

A.4 libgcc_s ........................................................................................................................................................ 1029

A.5 libm .............................................................................................................................................................. 1029

A.6 libncurses .................................................................................................................................................. 1033

A.7 libncursesw .............................................................................................................................................. 1036

A.8 libpam ......................................................................................................................................................... 1043

A.9 libpthread .................................................................................................................................................. 1043

A.10 librt ............................................................................................................................................................ 1047

A.11 libutil ......................................................................................................................................................... 1047

A.12 libz ............................................................................................................................................................. 1048

A.13 libnspr4 ................................................................................................................................................... 1049

A.14 libnss3 ...................................................................................................................................................... 1050

A.15 libssl3 ....................................................................................................................................................... 1051

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ISO/IEC 23360-1-2:2021(E)
Introduction
The LSB defines a binary interface for application programs that are compiled
and packaged for LSB-conforming implementations on many different hardware
architectures. A binary specification must include information specific to the

computer processor architecture for which it is intended. To avoid the complexity

of conditional descriptions, the specification has instead been divided into
generic parts which are augmented by one of several architecture-specific parts,
depending on the target processor architecture; the generic part will indicate
when reference must be made to the architecture part, and vice versa.
This document should be used in conjunction with the documents it references.
This document enumerates the system components it includes, but descriptions
of those components may be included entirely or partly in this document, partly
in other documents, or entirely in other reference documents. For example, the
section that describes system service routines includes a list of the system
routines supported in this interface, formal declarations of the data structures
they use that are visible to applications, and a pointer to the underlying
referenced specification for information about the syntax and semantics of each

call. Only those routines not described in standards referenced by this document,

or extensions to those standards, are described in the detail. Information
referenced in this way is as much a part of this document as is the information
explicitly included here.
The specification carries a version number of either the form x.y or x.y.z. This
version number carries the following meaning:
1. The first number (x) is the major version number. Versions sharing the same
major version number shall be compatible in a backwards direction; that is,
a newer version shall be compatible with an older version. Any deletion of
a library results in a new major version number. Interfaces marked as
deprecated may be removed from the specification at a major version
change.
2. The second number (y) is the minor version number. Libraries and
individual interfaces may be added, but not removed. Interfaces may be
marked as deprecated at a minor version change. Other minor changes may
be permitted at the discretion of the LSB workgroup.

3. The third number (z), if present, is the editorial level. Only editorial changes

should be included in such versions.

Since this specification is a descriptive Application Binary Interface, and not a

source level API specification, it is not possible to make a guarantee of 100%
backward compatibility between major releases. However, it is the intent that

those parts of the binary interface that are visible in the source level API will

remain backward compatible from version to version, except where a feature
marked as "Deprecated" in one release may be removed from a future release.
Implementors are strongly encouraged to make use of symbol versioning to
permit simultaneous support of applications
...