Linux Standard Base Languages Specification 3.2

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 may be 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
Apple Inc.
Easy Software Products
artofcode LLC
Till Kamppeter
Manfred Wassman
Python Software Foundation

These excerpts are being used in accordance with their respective licenses.

Linux is the registered trademark of Linus Torvalds in the U.S. and other countries.

UNIX is a registered trademark of The Open Group.

LSB is a trademark of the Linux Foundation in the United States and other countries.

AMD is a trademark of Advanced Micro Devices, Inc.

Intel and Itanium are registered trademarks and Intel386 is a trademark of Intel Corporation.

PowerPC is a registered trademark and PowerPC Architecture is a trademark of the IBM Corporation.

S/390 is a registered trademark of the IBM Corporation.

OpenGL is a registered trademark of Silicon Graphics, Inc.

Table of Contents

Foreword

Introduction

I. Introductory Elements

1. Scope
2. Normative References
3. Requirements
4. Definitions
5. Terminology

II. Python Interpreter

6. Python Interpreter

6.1. Introduction
6.2. Python Interpreter Location
6.3. Python Interpreter Version
6.4. Operators and Functions
6.5. Python Modules
6.6. Python Interpreter Command

III. Perl Interpreter

7. Perl Interpreter

7.1. Introduction
7.2. Perl Interpreter Location
7.3. Perl Interpreter Version
7.4. Perl Operators and Functions
7.5. Perl Modules
7.6. Perl Interpreter Command

A. GNU Free Documentation License (Informative)

A.1. PREAMBLE
A.2. APPLICABILITY AND DEFINITIONS
A.3. VERBATIM COPYING
A.4. COPYING IN QUANTITY
A.5. MODIFICATIONS
A.6. COMBINING DOCUMENTS
A.7. COLLECTIONS OF DOCUMENTS
A.8. AGGREGATION WITH INDEPENDENT WORKS
A.9. TRANSLATION
A.10. TERMINATION
A.11. FUTURE REVISIONS OF THIS LICENSE
A.12. How to use this License for your documents

List of Tables
2-1. Informative References
6-1. Required Python Modules
7-1. Required Perl Modules

Foreword

This is version 3.2 of the LSB Languages specification. This version is a preliminary version for review only. Conclusion of work on this version will result in version 3.2 of the LSB Languages specification.

Implmentations may not claim conformance to this version.

Introduction

The LSB Languages specification defines the runtime language components that are required to be present on a conforming system.

This document should be used in conjunction with the documents it references. Information referenced in this way is as much a part of this document as is the information explicitly included here.

I. Introductory Elements

Table of Contents
1. Scope
2. Normative References
3. Requirements
4. Definitions
5. Terminology

Chapter 1. Scope

The LSB Languages specification defines components for runtime languages which are found on an LSB conforming system.

Chapter 2. Normative References

The specifications listed below are referenced in whole or in part by the LSB Languages specification. Such references may be normative or informative; a reference to specification shall only be considered normative if it is explicitly cited as such. The LSB Languages specification may make normative references to a portion of these specifications (that is, to define a specific function or group of functions); in such cases, only the explicitly referenced portion of the specification is to be considered normative.

Table 2-1. Informative References

Name	Title	URL
Perl Core Modules	Perl 5.8.8 Core Modules	http://perldoc.perl.org/5.8.8/index-modules-A.html
Perl Functions	Perl 5.8.8 Functions	http://perldoc.perl.org/5.8.8/perlfunc.html
Perl Language Reference	Perl 5.8.8 Language Reference	http://perldoc.perl.org/5.8.8/index-language.html
Perl Manual	Perl 5.8.8 Manual Page	http://perldoc.perl.org/5.8.8/perlrun.html
Perl Operators	Perl 5.8.8 Operators and Precedence	http://perldoc.perl.org/5.8.8/perlop.html
Perl Syntax	Perl 5.8.8 Syntax	http://perldoc.perl.org/5.8.8/perlsyn.html
Python Library Reference	Python Library Reference Release 2.4.2	http://www.python.org/doc/2.4.2/lib/lib.html
Python Reference Manual	Python Reference Manual Release 2.4.2	http://www.python.org/doc/2.4.2/ref/ref.html

Chapter 3. Requirements

This specification describes runtime language interpreters which shall be found in specified locations. It also defines a number of runtime modules which shall be in an implementation-defined directory which the interpreters shall search by default.

Chapter 4. Definitions

For the purposes of this document, the following definitions, as specified in the ISO/IEC Directives, Part 2, 2001, 4th Edition, apply:

can		be able to; there is a possibility of; it is possible to
cannot		be unable to; there is no possibilty of; it is not possible to
may		is permitted; is allowed; is permissible
need not		it is not required that; no...is required
shall		is to; is required to; it is required that; has to; only...is permitted; it is necessary
shall not		is not allowed [permitted] [acceptable] [permissible]; is required to be not; is required that...be not; is not to be
should		it is recommended that; ought to
should not		it is not recommended that; ought not to

Chapter 5. Terminology

For the purposes of this document, the following terms apply:

implementation-defined: Describes a value or behavior that is not defined by this document but is selected by an implementor. The value or behavior may vary among implementations that conform to this document. An application should not rely on the existence of the value or behavior. An application that relies on such a value or behavior cannot be assured to be portable across conforming implementations. The implementor shall document such a value or behavior so that it can be used correctly by an application.
Shell Script: A file that is read by an interpreter (e.g., awk). The first line of the shell script includes a reference to its interpreter binary.
undefined: Describes the nature of a value or behavior not defined by this document which results from use of an invalid program construct or invalid data input. The value or behavior may vary among implementations that conform to this document. An application should not rely on the existence or validity of the value or behavior. An application that relies on any particular value or behavior cannot be assured to be portable across conforming implementations.
unspecified: Describes the nature of a value or behavior not specified by this document which results from use of a valid program construct or valid data input. The value or behavior may vary among implementations that conform to this document. An application should not rely on the existence or validity of the value or behavior. An application that relies on any particular value or behavior cannot be assured to be portable across conforming implementations.

II. Python Interpreter

Table of Contents

6. Python Interpreter

6.1. Introduction

6.2. Python Interpreter Location

6.3. Python Interpreter Version

6.4. Operators and Functions

6.5. Python Modules

6.6. Python Interpreter Command

PYTHON -- an interpreted, interactive, object-oriented programming language

Chapter 6. Python Interpreter

6.1. Introduction

The Python intrepreter API is described in the Python Library Reference, with the following requirements for an LSB conforming runtime.

6.2. Python Interpreter Location

The Python interpreter binary, or a link to the binary, shall exist at /usr/bin/python.

6.3. Python Interpreter Version

The default installed Python version shall be 2.4.2 or greater. Applications can depend on the 2.4 interfaces.

6.4. Operators and Functions

Core Python operators, subroutines, and built-in functions shall be present and shall operate as defined in Python Reference Manual.

6.5. Python Modules

Certain modules are required to be present on a conforming implementation. The behavior of the modules is goverened by the following specification:

Python Library Reference

The following Python Modules are required:

Table 6-1. Required Python Modules

array	audioop	binascii
bisect	cmath	codecs
collections	cPickle	crypt
cStringIO	csv	datetime
errno	exceptions	fcntl
gc	grp	heapq
hotshot	imp	itertools
locale	marshal	mmap
operator	os	ossaudiodev
parser	posix	pwd
random	re	resource
select	signal	socket
string	sys	syslog
termios	thread	time
unicodedata	weakref	zipimport
zlib

6.6. Python Interpreter Command

Table of Contents
PYTHON -- an interpreted, interactive, object-oriented programming language

This section contains a description of the python command.

PYTHON

Name

python -- an interpreted, interactive, object-oriented programming language

Synopsis

python [-d ] [-E ] [-h ] [-i ] [ -m module-name ] [-O ] [ -Q argument ] [-S ] [-t ] [-u ] [-v ] [-V ] [ -W argument ] [-x ] [ -c command | script | - ] [arguments]

DESCRIPTION

Python is an interpreted, interactive, object-oriented programming language that combines remarkable power with very clear syntax. For an introduction to programming in Python you are referred to the Python Tutorial. The Python Library Reference documents built-in and standard types, constants, functions and modules. Finally, the Python Reference Manual describes the syntax and semantics of the core language in (perhaps too) much detail. (These documents may be located via the INTERNET RESOURCES below; they may be installed on your system as well.)

Python's basic power can be extended with your own modules written in C or C++. On most systems such modules may be dynamically loaded. Python is also adaptable as an extension language for existing applications. See the internal documentation for hints.

Documentation for installed Python modules and packages can be viewed by running the pydoc program.

COMMAND LINE OPTIONS

`-c` command		Specify the command to execute (see next section). This terminates the option list (following options are passed as arguments to the command).
`-d`		Turn on parser debugging output (for wizards only, depending on compilation options).
`-E`		Ignore environment variables like PYTHONPATH and PYTHONHOME that modify the behavior of the interpreter.
`-h`		Prints the usage for the interpreter executable and exits.
`-i`		When a script is passed as first argument or the `-c` option is used, enter interactive mode after executing the script or the command. It does not read the $PYTHONSTARTUP file. This can be useful to inspect global variables or a stack trace when a script raises an exception.
`-m` module-name		Searches sys.path for the named module and runs the corresponding .py file as a script.
`-O`		Turn on basic optimizations. This changes the filename extension for compiled (bytecode) files from .pyc to .pyo. Given twice, causes docstrings to be discarded.
`-Q` argument		Division control; see PEP 238. The argument must be one of "old" (the default, int/int and long/long return an int or long), "new" (new division semantics, i.e. int/int and long/long returns a float), "warn" (old division semantics with a warning for int/int and long/long), or "warnall" (old division semantics with a warning for all use of the division operator). For a use of "warnall", see the Tools/scripts/fixdiv.py script.
`-S`		Disable the import of the module site and the site-dependent manipulations of sys.path that it entails.
`-t`		Issue a warning when a source file mixes tabs and spaces for indentation in a way that makes it depend on the worth of a tab expressed in spaces. Issue an error when the option is given twice.
`-u`		Force stdin, stdout and stderr to be totally unbuffered. On systems where it matters, also put stdin, stdout and stderr in binary mode. Note that there is internal buffering in xreadlines(), readlines() and file-object iterators ("for line in sys.stdin") which is not influenced by this option. To work around this, you will want to use "sys.stdin.readline()" inside a "while 1:" loop.
`-v`		Print a message each time a module is initialized, showing the place (filename or built-in module) from which it is loaded. When given twice, print a message for each file that is checked for when searching for a module. Also provides information on module cleanup at exit.
`-V`		Prints the Python version number of the executable and exits.
`-W` argument		Warning control. Python sometimes prints warning message to sys.stderr. A typical warning message has the following form: file:line: category: message. By default, each warning is printed once for each source line where it occurs. This option controls how often warnings are printed. Multiple `-W` options may be given; when a warning matches more than one option, the action for the last matching option is performed. Invalid `-W` options are ignored (a warning message is printed about invalid options when the first warning is issued). Warnings can also be controlled from within a Python program using the warnings module. The simplest form of argument is one of the following action strings (or a unique abbreviation): ignore to ignore all warnings; default to explicitly request the default behavior (printing each warning once per source line); all to print a warning each time it occurs (this may generate many messages if a warning is triggered repeatedly for the same source line, such as inside a loop); module to print each warning only only the first time it occurs in each module; once to print each warning only the first time it occurs in the program; or error to raise an exception instead of printing a warning message. The full form of argument is action:message:category:module:line. Here, action is as explained above but only applies to messages that match the remaining fields. Empty fields match all values; trailing empty fields may be omitted. The message field matches the start of the warning message printed; this match is case-insensitive. The category field matches the warning category. This must be a class name; the match test whether the actual warning category of the message is a subclass of the specified warning category. The full class name must be given. The module field matches the (fully-qualified) module name; this match is case-sensitive. The line field matches the line number, where zero matches all line numbers and is thus equivalent to an omitted line number.
`-x`		Skip the first line of the source. This is intended for a DOS specific hack only. Warning: the line numbers in error messages will be off by one!

INTERPRETER INTERFACE

The interpreter interface resembles that of the UNIX shell: when called with standard input connected to a tty device, it prompts for commands and executes them until an EOF is read; when called with a file name argument or with a file as standard input, it reads and executes a script from that file; when called with -c command, it executes the Python statement(s) given as command. Here command may contain multiple statements separated by newlines. Leading whitespace is significant in Python statements! In non-interactive mode, the entire input is parsed before it is executed.

If available, the script name and additional arguments thereafter are passed to the script in the Python variable sys.argv , which is a list of strings (you must first import sys to be able to access it). If no script name is given, sys.argv[0] is an empty string; if -c is used, sys.argv[0] contains the string '-c'. Note that options interpreted by the Python interpreter itself are not placed in sys.argv.

In interactive mode, the primary prompt is >>>; the second prompt (which appears when a command is not complete) is .... The prompts can be changed by assignment to sys.ps1 or sys.ps2. The interpreter quits when it reads an EOF at a prompt. When an unhandled exception occurs, a stack trace is printed and control returns to the primary prompt; in non-interactive mode, the interpreter exits after printing the stack trace. The interrupt signal raises the Keyboard�Interrupt exception; other UNIX signals are not caught (except that SIGPIPE is sometimes ignored, in favor of the IOError exception). Error messages are written to stderr.

FILES AND DIRECTORIES

These are subject to difference depending on local installation conventions; ${prefix} and ${exec_prefix} are installation-dependent and should be interpreted as for GNU software; they may be the same. The default for both is /usr/local.

${exec_prefix}/bin/python: Recommended location of the interpreter.

${prefix}/lib/python<version> ${exec_prefix}/lib/python<version>

Recommended locations of the directories containing the standard modules.

${prefix}/include/python<version> ${exec_prefix}/include/python<version>

Recommended locations of the directories containing the include files needed for developing Python extensions and embedding the interpreter.

~/.pythonrc.py

User-specific initialization file loaded by the user module; not used by default or by most applications.

ENVIRONMENT VARIABLES

PYTHONHOME		Change the location of the standard Python libraries. By default, the libraries are searched in ${prefix}/lib/python<version> and ${exec_prefix}/lib/python<version>, where ${prefix} and ${exec_prefix} are installation-dependent directories, both defaulting to `/usr/local`. When $PYTHONHOME is set to a single directory, its value replaces both ${prefix} and ${exec_prefix}. To specify different values for these, set $PYTHONHOME to ${prefix}:${exec_prefix}.
PYTHONPATH		Augments the default search path for module files. The format is the same as the shell's $PATH: one or more directory pathnames separated by colons. Non-existent directories are silently ignored. The default search path is installation dependent, but generally begins with ${prefix}/lib/python<version> (see PYTHONHOME above). The default search path is always appended to $PYTHONPATH. If a script argument is given, the directory containing the script is inserted in the path in front of $PYTHONPATH. The search path can be manipulated from within a Python program as the variable sys.path .
PYTHONSTARTUP		If this is the name of a readable file, the Python commands in that file are executed before the first prompt is displayed in interactive mode. The file is executed in the same name space where interactive commands are executed so that objects defined or imported in it can be used without qualification in the interactive session. You can also change the prompts sys.ps1 and sys.ps2 in this file.
PYTHONY2K		Set this to a non-empty string to cause the time module to require dates specified as strings to include 4-digit years, otherwise 2-digit years are converted based on rules described in the time module documentation.
PYTHONOPTIMIZE		If this is set to a non-empty string it is equivalent to specifying the `-O` option. If set to an integer, it is equivalent to specifying `-O` multiple times.
PYTHONDEBUG		If this is set to a non-empty string it is equivalent to specifying the `-d` option. If set to an integer, it is equivalent to specifying `-d` multiple times.
PYTHONINSPECT		If this is set to a non-empty string it is equivalent to specifying the `-i` option.
PYTHONUNBUFFERED		If this is set to a non-empty string it is equivalent to specifying the `-u` option.
PYTHONVERBOSE		If this is set to a non-empty string it is equivalent to specifying the `-v` option. If set to an integer, it is equivalent to specifying `-v` multiple times.

AUTHOR

The Python Software Foundation: http://www.python.org/psf

INTERNET RESOURCES

Main website: http://www.python.org/ Documentation: http://docs.python.org/ Community website: http://starship.python.net/ Developer resources: http://www.python.org/dev/ FTP: ftp://ftp.python.org/pub/python/ Module repository: http://www.vex.net/parnassus/ Newsgroups: comp.lang.python, comp.lang.python.announce

LICENSING

Python is distributed under an Open Source license. See the file "LICENSE" in the Python source distribution for information on terms & conditions for accessing and otherwise using Python and for a DISCLAIMER OF ALL WARRANTIES.

III. Perl Interpreter

Table of Contents

7. Perl Interpreter

7.1. Introduction
7.2. Perl Interpreter Location
7.3. Perl Interpreter Version
7.4. Perl Operators and Functions
7.5. Perl Modules
7.6. Perl Interpreter Command

Chapter 7. Perl Interpreter

7.1. Introduction

The Perl intrepreter API is described in the Perl Language Reference, with the following requirements for an LSB conforming runtime.

7.2. Perl Interpreter Location

The Perl interpreter binary, or a link to the binary, shall exist at /usr/bin/perl.

7.3. Perl Interpreter Version

The default installed Perl version shall be 5.8.X with X >= 8.

7.4. Perl Operators and Functions

Core Perl operators, subroutines, and built-in functions shall be present and shall operate as defined in Perl Syntax, Perl Operators and Perl Functions.

7.5. Perl Modules

Certain modules are required to be present on a conforming implementation. The behavior of the modules is goverened by the following specification:

Perl Core Modules

The following Perl Modules are required:

Table 7-1. Required Perl Modules

AnyDBM_File	Attribute::Handlers	attributes
AutoLoader	AutoSplit	autouse
base	B::Concise	B::Debug
B::Deparse	Benchmark	bigint
bignum	bigrat	blib
B::Lint	B::Showlex	B::Terse
B::Xref	bytes	Carp
Carp::Heavy	CGI	CGI::Apache
CGI::Carp	CGI::Cookie	CGI::Fast
CGI::Pretty	CGI::Push	CGI::Switch
CGI::Util	charnames	Class::ISA
Class::Struct	constant	CPAN
CPAN::FirstTime	CPAN::Nox	Cwd
Data::Dumper	DB	DBM_Filter
DBM_Filter::compress	DBM_Filter::encode	DBM_Filter::int32
DBM_Filter::null	DBM_Filter::utf8	Devel::DProf
Devel::Peek	Devel::PPPort	Devel::SelfStubber
diagnostics	Digest	Digest::base
Digest::file	Digest::MD5	DirHandle
Dumpvalue	Encode	Encode::Alias
Encode::Byte	Encode::CJKConstants	Encode::CN
Encode::CN::HZ	Encode::Config	Encode::EBCDIC
Encode::Encoder	Encode::encoding	Encode::Encoding
Encode::Guess	Encode::JP	Encode::JP::H2Z
Encode::JP::JIS7	Encode::KR	Encode::KR::2022_KR
Encode::MIME::Header	Encode::MIME::Header::ISO_2022_JP	Encode::Symbol
Encode::TW	Encode::Unicode	Encode::Unicode::UTF7
English	Env	Exporter
Exporter::Heavy	ExtUtils::Command	ExtUtils::Command::MM
ExtUtils::Constant	ExtUtils::Constant::Base	ExtUtils::Constant::Utils
ExtUtils::Constant::XS	ExtUtils::Embed	ExtUtils::Install
ExtUtils::Installed	ExtUtils::Liblist	ExtUtils::Liblist::Kid
ExtUtils::MakeMaker::bytes	ExtUtils::MakeMaker::Config	ExtUtils::Manifest
ExtUtils::Mkbootstrap	ExtUtils::Mksymlists	ExtUtils::MM_AIX
ExtUtils::MM_Any	ExtUtils::MM_BeOS	ExtUtils::MM_DOS
ExtUtils::MM_MacOS	ExtUtils::MM_NW5	ExtUtils::MM_OS2
ExtUtils::MM_QNX	ExtUtils::MM_Unix	ExtUtils::MM_VOS
ExtUtils::MY	ExtUtils::Packlist	ExtUtils::testlib
Fatal	Fcntl	fields
File::Basename	FileCache	File::CheckTree
File::Compare	File::Copy	File::DosGlob
File::Find	File::Glob	FileHandle
File::Path	File::Spec::Epoc	File::Spec::Functions
File::Spec::Mac	File::Spec::OS2	File::Spec::Unix
File::stat	File::Temp	filetest
Filter::Simple	Filter::Util::Call	FindBin
GDBM_File	Getopt::Long	Getopt::Std
Hash::Util	I18N::Collate	I18N::Langinfo
I18N::LangTags	I18N::LangTags::Detect	I18N::LangTags::List
if	integer	IO
IO::Dir	IO::File	IO::Handle
IO::Pipe	IO::Poll	IO::Seekable
IO::Select	IO::Socket	IO::Socket::INET
IO::Socket::UNIX	IPC::Open2	IPC::Open3
IPC::SysV	IPC::SysV::Msg	IPC::SysV::Semaphore
less	List::Util	List::Util::Scalar
locale	Locale::Constants	Locale::Country
Locale::Currency	Locale::Language	Locale::Maketext
Locale::Maketext::Guts	Locale::Maketext::GutsLoader	Locale::Script
Math::BigFloat	Math::BigFloat::Trace	Math::BigInt
Math::BigInt::Calc	Math::BigInt::CalcEmu	Math::BigInt::Trace
Math::BigRat	Math::Complex	Math::Trig
Memoize	Memoize::AnyDBM_File	Memoize::Expire
Memoize::ExpireFile	Memoize::ExpireTest	�
Memoize::SDBM_File	Memoize::Storable	MIME::Base64
MIME::Base64::QuotedPrint	Net::Cmd	Net::Config
Net::Domain	Net::FTP	Net::FTP::A
Net::FTP::dataconn	Net::FTP::E	Net::FTP::I
Net::FTP::L	Net::hostent	Net::netent
Net::Netrc	Net::NNTP	Net::Ping
Net::POP3	Net::protoent	Net::servent
Net::SMTP	Net::Time	NEXT
O	Opcode	Opcode::ops
Opcode::Safe	open	overload
PerlIO	PerlIO::encoding	PerlIO::scalar
PerlIO::via	PerlIO::via::QuotedPrint	Pod::Checker
Pod::Find	Pod::Functions	Pod::Html
Pod::InputObjects	Pod::LaTeX	Pod::Man
Pod::ParseLink	Pod::Parser	Pod::ParseUtils
Pod::Perldoc	Pod::Perldoc::BaseTo	Pod::Perldoc::GetOptsOO
Pod::Perldoc::ToChecker	Pod::Perldoc::ToMan	Pod::Perldoc::ToNroff
Pod::Perldoc::ToPod	Pod::Perldoc::ToRtf	Pod::Perldoc::ToText
Pod::Perldoc::ToTk	Pod::Perldoc::ToXml	Pod::Plainer
Pod::PlainText	Pod::Select	Pod::Text
Pod::Text::Color	Pod::Text::Overstrike	Pod::Text::Termcap
Pod::Usage	POSIX	re
SDBM_File	Search::Dict	SelectSaver
SelfLoader	Shell	sigtrap
Socket	sort	Storable
strict	subs	Switch
Symbol	Sys::Hostname	Sys::Syslog
Term::ANSIColor	Term::Cap	Term::Complete
Term::ReadLine	Test	Test::Builder
Test::Builder::Module	Test::Builder::Tester	Test::Builder::Tester::Color
Test::Harness	Test::Harness::Assert	Test::Harness::Iterator
Test::Harness::Point	Test::Harness::Straps	Test::More
Test::Simple	Text::Abbrev	Text::Balanced
Text::ParseWords	Text::Soundex	Text::Tabs
Text::Wrap	Tie::Array	Tie::File
Tie::Handle	Tie::Hash	Tie::Memoize
Tie::RefHash	Tie::Scalar	Tie::SubstrHash
Time::gmtime	Time::HiRes	Time::Local
Time::localtime	Time::tm	Unicode::Collate
Unicode::Normalize	Unicode::UCD	UNIVERSAL
User::grent	User::pwent	utf8
warnings	warnings::register	XS::APItest
XS::Typemap

7.6. Perl Interpreter Command

The perl command is described in Perl Manual.

Appendix A. GNU Free Documentation License (Informative)

This specification is published under the terms of the GNU Free Documentation License, Version 1.1, March 2000

Copyright (C) 2000 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

A.1. PREAMBLE

The purpose of this License is to make a manual, textbook, or other written document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

A.2. APPLICABILITY AND DEFINITIONS

This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you".

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (For example, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License.

The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License.

A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, whose contents can be viewed and edited directly and straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup has been designed to thwart or discourage subsequent modification by readers is not Transparent. A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML designed for human modification. Opaque formats include PostScript, PDF, proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML produced by some word processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.

A.3. VERBATIM COPYING

You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and you may publicly display copies.

A.4. COPYING IN QUANTITY

If you publish printed copies of the Document numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a publicly-accessible computer-network location containing a complete Transparent copy of the Document, free of added material, which the general network-using public has access to download anonymously at no charge using public-standard network protocols. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

A.5. MODIFICATIONS

You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.
List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has less than five).
State on the Title page the name of the publisher of the Modified Version, as the publisher.
Preserve all the copyright notices of the Document.
Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.
Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.
Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.
Include an unaltered copy of this License.
Preserve the section entitled "History", and its title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.
Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.
In any section entitled "Acknowledgements" or "Dedications", preserve the section's title, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.
Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.
Delete any section entitled "Endorsements". Such a section may not be included in the Modified Version.
Do not retitle any existing section as "Endorsements" or to conflict in title with any Invariant Section.

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

You may add a section entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

A.6. COMBINING DOCUMENTS

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections entitled "History" in the various original documents, forming one section entitled "History"; likewise combine any sections entitled "Acknowledgements", and any sections entitled "Dedications". You must delete all sections entitled "Endorsements."

A.7. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

A.8. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, does not as a whole count as a Modified Version of the Document, provided no compilation copyright is claimed for the compilation. Such a compilation is called an "aggregate", and this License does not apply to the other self-contained works thus compiled with the Document, on account of their being thus compiled, if they are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one quarter of the entire aggregate, the Document's Cover Texts may be placed on covers that surround only the Document within the aggregate. Otherwise they must appear on covers around the whole aggregate.

A.9. TRANSLATION

Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License provided that you also include the original English version of this License. In case of a disagreement between the translation and the original English version of this License, the original English version will prevail.

A.10. TERMINATION

You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

A.11. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

A.12. How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

Copyright (c) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. A copy of the license is included in the section entitled "GNU Free Documentation License".

If you have no Invariant Sections, write "with no Invariant Sections" instead of saying which ones are invariant. If you have no Front-Cover Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise for Back-Cover Texts.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.