Linux Standard Base Core Specification 3.01 Linux Standard Base Core Specification 3.01 Copyright © 2004, 2005 Free Standards Group Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". Portions of the text are copyrighted by the following parties: • The Regents of the University of California • Free Software Foundation • Ian F. Darwin • Paul Vixie • BSDI (now Wind River) • Andrew G Morgan • Jean-loup Gailly and Mark Adler • Massachusetts Institute of Technology These excerpts are being used in accordance with their respective licenses. Linux is a trademark of Linus Torvalds. UNIX a registered trademark of the Open Group in the United States and other countries. LSB is a trademark of the Free Standards Group in the USA and other countries. AMD is a trademark of Advanced Micro Devices, Inc. Intel and Itanium are registered trademarks and Intel386 is a trademarks of Intel Corporation. PowerPC and PowerPC Architecture are trademarks of the IBM Corporation. OpenGL is a registered trademark of Silicon Graphics, Inc. Contents Foreword............................................................................................................................ vii5 Introduction ..................................................................................................................... viii5 I Introductory Elements ..................................................................................................... 95 1 Scope........................................................................................................................ 105 1.1 General........................................................................................................ 105 1.2 Module Specific Scope.............................................................................. 105 2 Normative References........................................................................................... 115 3 Requirements2.1 Normative References................................................... 11 3.1 Relevant Libraries2.2 Informative References/Bibliography ............. 14 3.2 LSB Implementation Conformance3 Requirements....................................... 17 3.3 LSB Application Conformance3.1 Relevant Libraries.......................... 17 4 Definitions3.2 LSB Implementation Conformance.................................. 17 5 Terminology3.3 LSB Application Conformance ...................................... 18 6 Documentation Conventions4 Definitions......................................................... 20 7 Relationship To ISO/IEC 9945 POSIX5 Terminology ...................................... 21 8 Relationship To Other Free Standards Group Specifications6 Documentation Conventions..................................................................................................... 23 II Executable And Linking Format (ELF)7 Relationship To ISO/IEC 9945 POSIX................................................................................................................ 24 9 Introduction8 Relationship To Other Free Standards Group Specifications. 25 10 Low Level System InformationII Executable And Linking Format (ELF) .......... 26 10.1 Operating System Interface9 Introduction.................................................... 27 10.2 Machine Interface10 Low Level System Information .................................. 28 11 Object Format10.1 Operating System Interface...................................... 28 11.1 Object Files10.2 Machine Interface........................................................ 28 11.2 Sections11 Object Format................................................................................. 29 11.3 Special Sections11.1 Object Files ........................................................... 29 11.4 Symbol Mapping11.2 Sections............................................................... 29 11.5 DWARF Extensions11.3 Special Sections............................................. 32 11.6 Exception Frames11.4 Symbol Mapping.............................................. 38 11.7 Symbol Versioning11.5 DWARF Extensions....................................... 38 11.8 ABI note tag11.6 Exception Frames ...................................................... 41 12 Dynamic Linking11.7 Symbol Versioning .............................................. 46 12.1 Program Loading and Dynamic Linking11.8 ABI note tag............... 50 12.2 Program Header12 Dynamic Linking............................................................ 51 12.31 Program Loading and Dynamic EntriesLinking............................... 51 III Base Libraries12.2 Program Header....................................................... 51 13 Base Libraries12.3 Dynamic Entries......................................................... 51 13.1 IntroductionIII Base Libraries................................................................................. 56 13.2 Program Interpreter13 Base Libraries............................................................ 57 13.3 Interfaces for libc13.1 Introduction....................................................... 57 13.4 Data Definitions for libc13.2 Program Interpreter.............................. 57 13.5 Interface Definitions3 Interfaces for libc .............................................. 575 13.6 Interfaces for libm13.4 Data Definitions for libc ................................. 79 13.7 Data5 Interface Definitions for libmlibc............................................. 136 13.8 Interface Definitions6 Interfaces for libm .......................................... 2415 13.9 Interfaces for libpthread13.7 Data Definitions for libm ................... 247 13.10 Data8 Interface Definitions for libpthreadlibm............................... 253 13.11 Interface Definitions9 Interfaces for libpthread .............................. 2545 iii 13.12 Interfaces for libgcc_s13.10 Data Definitions for libpthread ......... 258 13.13 Data11 Interface Definitions for libgcc_slibpthread....................... 265 13.1412 Interfaces for libdllibgcc_s ............................................................. 265 13.1513 Data Definitions for libdllibgcc_s.................................................. 266 13.16 Interface Definitions14 Interfaces for libdl ...................................... 2695 13.17 Interfaces for librt13.15 Data Definitions for libdl.......................... 270 13.18 Interfaces for libcrypt13.16 Interface Definitions for libdl............. 271 13.1917 Interfaces for libpamlibrt................................................................ 273 13.20 Data Definitions for libpam13.18 Interfaces for libcrypt ............... 275 13.21 Interface Definitions19 Interfaces for libpam .................................. 2755 IV Utility Libraries13.20 Data Definitions for libpam ............................ 276 14 Utility Libraries13.21 Interface Definitions for libpam ....................... 278 14.1 IntroductionIV Utility Libraries ........................................................................... 291 14.2 Interfaces for libz14 Utility Libraries ........................................................... 292 14.3 Data Definitions for libz14.1 Introduction......................................... 292 14.4 Interface Definitions2 Interfaces for libz............................................ 2925 14.5 Interfaces for libncurses14.3 Data Definitions for libz ..................... 293 14.6 Data4 Interface Definitions for libncurseslibz................................... 296 14.75 Interfaces for libutillibncurses........................................................... 342 14.8 Interface6 Data Definitions for libutillibncurses............................... 349 V Commands and Utilities14.7 Interfaces for libutil .............................. 358 15 Commands and Utilities14.8 Interface Definitions for libutil ............ 359 15.1V Commands and Utilities ..................................................................................... 365 15.2 Command Behavior15 Commands and Utilities........................................ 366 VI Execution Environment15.1 Commands and Utilities ...................... 366 16 File System Hierarchy15.2 Command Behavior .................................. 368 16.1 /dev: Device FilesVI Execution Environment .................................................... 429 16.2 /etc: Host-specific system configuration16 File System Hierarchy........ 430 16.3 User Accounting Databases16.1 /dev: Device Files ......................... 430 16.4 Path For System Administration Utilities16.2 /etc: Host-specific system configuration........................................................................... 430 17 Additional Recommendations16.3 User Accounting Databases ....... 432 17.1 Recommendations for applications on ownership and permissions16.4 Path For System Administration Utilities ........... 432 1817 Additional BehaviorsRecommendations.................................................... 433 18.1 Mandatory Optional Behaviors17.1 Recommendations for applications on ownership and permissions ................................... 433 19 Localization18 Additional Behaviors.............................................................. 435 19.1 Introduction18.1 Mandatory Optional Behaviors............................. 435 19.2 Regular Expressions19