Changeset 609 for branches/GNU/src/binutils/etc/standards.texi

Timestamp:

Aug 16, 2003, 6:59:22 PM (22 years ago)

Author:

bird

Message:

binutils v2.14 - offical sources.

File:

• branches/GNU/src/binutils/etc/standards.texi (modified) (103 diffs, 1 prop)

branches/GNU/src/binutils/etc/standards.texi

@@ -4 +4 @@
 @settitle GNU Coding Standards
 @c This date is automagically updated when you save this file:
-@set lastupdate March 13, 1998
+@set lastupdate February 14, 2002
 @c %**end of header
 
@@ -17 +17 @@
 @c @setchapternewpage odd
 @setchapternewpage off
+
+@c Put everything in one index (arbitrarily chosen to be the concept index).
+@syncodeindex fn cp
+@syncodeindex ky cp
+@syncodeindex pg cp
+@syncodeindex vr cp
 
 @c This is used by a cross ref in make-stds.texi
@@ -29 +35 @@
 @ifinfo
 GNU Coding Standards
-Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-@ignore
-Permission is granted to process this file through TeX and print the
-results, provided the printed document carries copying permission
-notice identical to this one except for the removal of this paragraph
-(this paragraph not being relevant to the printed manual).
-@end ignore
-
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided that the entire
-resulting derived work is distributed under the terms of a permission
-notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that this permission notice may be stated in a translation approved
-by the Free Software Foundation.
+Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+
+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 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''.
 @end ifinfo
 
 @titlepage
 @title GNU Coding Standards
-@author Richard Stallman
+@author Richard Stallman, et al.
 @author last updated @value{lastupdate}
 @page
 
 @vskip 0pt plus 1filll
-Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided that the entire
-resulting derived work is distributed under the terms of a permission
-notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that this permission notice may be stated in a translation approved
-by the Free Software Foundation.
+Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+
+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 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''.
 @end titlepage
 
@@ -86 +73 @@
 @menu
 * Preface::                     About the GNU Coding Standards
-* Intellectual Property::       Keeping Free Software Free
+* Legal Issues::                Keeping Free Software Free
 * Design Advice::               General Program Design
 * Program Behavior::            Program Behavior for All Programs
@@ -92 +79 @@
 * Documentation::               Documenting Programs
 * Managing Releases::           The Release Process
+* References::                  References to Non-Free Software or Documentation
+* Copying This Manual::         How to Make Copies of This Manual
+* Index::                       
+
 @end menu
 
@@ -105 +96 @@
 state reasons for writing in a certain way.
 
+This release of the GNU Coding Standards was last updated
+@value{lastupdate}.
+
+@cindex where to obtain @code{standards.texi}
+@cindex downloading this manual
+If you did not obtain this file directly from the GNU project and
+recently, please check for a newer version.  You can ftp the GNU
+Coding Standards from any GNU FTP host in the directory
+@file{/pub/gnu/standards/}.  The GNU Coding Standards are available
+there in several different formats: @file{standards.text},
+@file{standards.info}, and @file{standards.dvi}, as well as the
+Texinfo ``source'' which is divided in two files:
+@file{standards.texi} and @file{make-stds.texi}.  The GNU Coding
+Standards are also available on the GNU World Wide Web server:
+@uref{http://www.gnu.org/prep/standards_toc.html}.
+
 Corrections or suggestions for this document should be sent to
-@email{gnu@@gnu.org}.  If you make a suggestion, please include a
+@email{bug-standards@@gnu.org}.  If you make a suggestion, please include a
 suggested new wording for it; our time is limited.  We prefer a context
 diff to the @file{standards.texi} or @file{make-stds.texi} files, but if
 you don't have those files, please mail your suggestion anyway.
 
-This release of the GNU Coding Standards was last updated
-@value{lastupdate}.
-
-@node Intellectual Property
+These standards cover the minimum of what is important when writing a
+GNU package.  Likely, the needs for additional standards will come up.
+Sometimes, you might suggest that such standards be added to this
+document.  If you think your standards would be generally useful, please
+do suggest them.
+
+You should also set standards for your package on many questions not
+addressed or not firmly specified here.  The most important point is to
+be self-consistent---try to stick to the conventions you pick, and try
+to document them as much as possible.  That way, your program will be
+more maintainable by others.
+
+@node Legal Issues
 @chapter Keeping Free Software Free
+@cindex legal aspects
 
 This @value{CHAPTER} discusses how you can make sure that GNU software
-remains unencumbered.
+avoids legal difficulties, and other related issues.
 
 @menu
 * Reading Non-Free Code::       Referring to Proprietary Programs
 * Contributions::               Accepting Contributions
+* Trademarks::                  How We Deal with Trademark Issues
 @end menu
 
 @node Reading Non-Free Code
 @section Referring to Proprietary Programs
+@cindex proprietary programs
+@cindex avoiding proprietary code
 
 Don't in any circumstances refer to Unix source code for or during
@@ -158 +178 @@
 to free memory, or use a new GNU facility such as obstacks.
 
-
 @node Contributions
 @section Accepting Contributions
-
-If someone else sends you a piece of code to add to the program you are
-working on, we need legal papers to use it---the same sort of legal
-papers we will need to get from you.  @emph{Each} significant
-contributor to a program must sign some sort of legal papers in order
-for us to have clear title to the program.  The main author alone is not
+@cindex legal papers
+@cindex accepting contributions
+
+If the program you are working on is copyrighted by the Free Software
+Foundation, then when someone else sends you a piece of code to add to
+the program, we need legal papers to use it---just as we asked you to
+sign papers initially.  @emph{Each} person who makes a nontrivial
+contribution to a program must sign some sort of legal papers in order
+for us to have clear title to the program; the main author alone is not
 enough.
 
@@ -182 +204 @@
 text, so we need legal papers for all kinds.
 
+We know it is frustrating to ask for legal papers; it's frustrating for
+us as well.  But if you don't wait, you are going out on a limb---for
+example, what if the contributor's employer won't sign a disclaimer?
+You might have to take that code out again!
+
 You don't need papers for changes of a few lines here or there, since
 they are not significant for copyright purposes.  Also, you don't need
 papers if all you get from the suggestion is some ideas, not actual code
-which you use.  For example, if you write a different solution to the
-problem, you don't need to get papers.
-
-We know this is frustrating; it's frustrating for us as well.  But if
-you don't wait, you are going out on a limb---for example, what if the
-contributor's employer won't sign a disclaimer?  You might have to take
-that code out again!
+which you use.  For example, if someone send you one implementation, but
+you write a different implementation of the same idea, you don't need to
+get papers.
 
 The very worst thing is if you forget to tell us about the other
@@ -201 +224 @@
 released or not), please ask us for a copy.
 
+@node Trademarks
+@section Trademarks
+@cindex trademarks
+
+Please do not include any trademark acknowledgements in GNU software
+packages or documentation.
+
+Trademark acknowledgements are the statements that such-and-such is a
+trademark of so-and-so.  The GNU Project has no objection to the basic
+idea of trademarks, but these acknowledgements feel like kowtowing, so
+we don't use them.  There is no legal requirement for them.
+
+What is legally required, as regards other people's trademarks, is to
+avoid using them in ways which a reader might read as naming or labeling
+our own programs or activities.  For example, since ``Objective C'' is
+(or at least was) a trademark, we made sure to say that we provide a
+``compiler for the Objective C language'' rather than an ``Objective C
+compiler''.  The latter is meant to be short for the former, but it does
+not explicitly state the relationship, so it could be misinterpreted as
+using ``Objective C'' as a label for the compiler rather than for the
+language.
+
 @node Design Advice
 @chapter General Program Design
+@cindex program design
 
 This @value{CHAPTER} discusses some of the issues you should take into
 account when designing your program.
 
+@c                         Standard or ANSI C
+@c
+@c In 1989 the American National Standards Institute (ANSI) standardized
+@c C   as  standard  X3.159-1989.    In  December   of  that   year  the
+@c International Standards Organization ISO  adopted the ANSI C standard
+@c making  minor changes.   In 1990  ANSI then  re-adopted  ISO standard
+@c C. This version of C is known as either ANSI C or Standard C.
+
+@c A major revision of the C Standard appeared in 1999.
+
 @menu
+* Source Language::             Which languges to use.
 * Compatibility::               Compatibility with other implementations
 * Using Extensions::            Using non-standard features
-* ANSI C::                      Using ANSI C features
-* Source Language::             Using languages other than C
+* Standard C::                  Using Standard C features
+* Conditional Compilation::     Compiling Code Only If A Conditional is True
 @end menu
+
+@node Source Language
+@section Which Languages to Use
+@cindex programming languges
+
+When you want to use a language that gets compiled and runs at high
+speed, the best language to use is C.  Using another language is like
+using a non-standard feature: it will cause trouble for users.  Even if
+GCC supports the other language, users may find it inconvenient to have
+to install the compiler for that other language in order to build your
+program.  For example, if you write your program in C++, people will
+have to install the GNU C++ compiler in order to compile your program.
+
+C has one other advantage over C++ and other compiled languages: more
+people know C, so more people will find it easy to read and modify the
+program if it is written in C.
+
+So in general it is much better to use C, rather than the
+comparable alternatives.
+
+But there are two exceptions to that conclusion:
+
+@itemize @bullet
+@item
+It is no problem to use another language to write a tool specifically
+intended for use with that language.  That is because the only people
+who want to build the tool will be those who have installed the other
+language anyway.
+
+@item
+If an application is of interest only to a narrow part of the community,
+then the question of which language it is written in has less effect on
+other people, so you may as well please yourself.
+@end itemize
+
+Many programs are designed to be extensible: they include an interpreter
+for a language that is higher level than C.  Often much of the program
+is written in that language, too.  The Emacs editor pioneered this
+technique.
+
+@cindex GUILE
+The standard extensibility interpreter for GNU software is GUILE, which
+implements the language Scheme (an especially clean and simple dialect
+of Lisp).  @uref{http://www.gnu.org/software/guile/}.  We don't reject
+programs written in other ``scripting languages'' such as Perl and
+Python, but using GUILE is very important for the overall consistency of
+the GNU system.
 
 @node Compatibility
 @section Compatibility with Other Implementations
+@cindex compatibility with C and @sc{posix} standards
+@cindex @sc{posix} compatibility
 
 With occasional exceptions, utility programs and libraries for GNU
 should be upward compatible with those in Berkeley Unix, and upward
-compatible with @sc{ansi} C if @sc{ansi} C specifies their behavior, and
-upward compatible with @sc{POSIX} if @sc{POSIX} specifies their
-behavior.
+compatible with Standard C if Standard C specifies their
+behavior, and upward compatible with @sc{posix} if @sc{posix} specifies
+their behavior.
 
 When these standards conflict, it is useful to offer compatibility
 modes for each of them.
 
-@sc{ansi} C and @sc{POSIX} prohibit many kinds of extensions.  Feel free
-to make the extensions anyway, and include a @samp{--ansi},
+@cindex options for compatibility
+Standard C and @sc{posix} prohibit many kinds of extensions.  Feel
+free to make the extensions anyway, and include a @samp{--ansi},
 @samp{--posix}, or @samp{--compatible} option to turn them off.
 However, if the extension has a significant chance of breaking any real
-programs or scripts, then it is not really upward compatible.  Try to
-redesign its interface.
-
-Many GNU programs suppress extensions that conflict with POSIX if the
+programs or scripts, then it is not really upward compatible.  So you
+should try to redesign its interface to make it upward compatible.
+
+@cindex @code{POSIXLY_CORRECT}, environment variable
+Many GNU programs suppress extensions that conflict with @sc{posix} if the
 environment variable @code{POSIXLY_CORRECT} is defined (even if it is
 defined with a null value).  Please make your program recognize this
@@ -244 +352 @@
 feature as well.  (There is a free @code{vi} clone, so we offer it.)
 
-Additional useful features not in Berkeley Unix are welcome.
+Additional useful features are welcome regardless of whether
+there is any precedent for them.
 
 @node Using Extensions
 @section Using Non-standard Features
+@cindex non-standard extensions
 
 Many GNU facilities that already exist support a number of convenient
@@ -268 +378 @@
 
 An exception to this rule are the large, established programs (such as
-Emacs) which run on a great variety of systems.  Such programs would
-be broken by use of GNU extensions.
-
-Another exception is for programs that are used as part of
-compilation: anything that must be compiled with other compilers in
-order to bootstrap the GNU compilation facilities.  If these require
-the GNU compiler, then no one can compile them without having them
-installed already.  That would be no good.
-
-@node ANSI C
-@section @sc{ansi} C and pre-@sc{ansi} C
-
-Do not ever use the ``trigraph'' feature of @sc{ansi} C.
-
-@sc{ansi} C is widespread enough now that it is ok to write new programs
-that use @sc{ansi} C features (and therefore will not work in
-non-@sc{ansi} compilers).  And if a program is already written in
-@sc{ansi} C, there's no need to convert it to support non-@sc{ansi}
-compilers.
-
-However, it is easy to support non-@sc{ansi} compilers in most programs,
-so you might still consider doing so when you write a program.  Instead
-of writing function definitions in @sc{ansi} prototype form,
+Emacs) which run on a great variety of systems.  Using GNU extensions in
+such programs would make many users unhappy, so we don't do that.
+
+Another exception is for programs that are used as part of compilation:
+anything that must be compiled with other compilers in order to
+bootstrap the GNU compilation facilities.  If these require the GNU
+compiler, then no one can compile them without having them installed
+already.  That would be extremely troublesome in certain cases.
+
+@node Standard C
+@section Standard C and Pre-Standard C
+@cindex @sc{ansi} C standard
+
+1989 Standard C is widespread enough now that it is ok to use its
+features in new programs.  There is one exception: do not ever use the
+``trigraph'' feature of Standard C.
+
+1999 Standard C is not widespread yet, so please do not require its
+features in programs.  It is ok to use its features if they are present.
+
+However, it is easy to support pre-standard compilers in most programs,
+so if you know how to do that, feel free.  If a program you are
+maintaining has such support, you should try to keep it working.
+
+@cindex function prototypes
+To support pre-standard C, instead of writing function definitions in
+standard prototype form,
 
 @example
@@ -299 +413 @@
 
 @noindent
-write the definition in pre-@sc{ansi} style like this,
+write the definition in pre-standard style like this,
 
 @example
@@ -316 +430 @@
 
 You need such a declaration anyway, in a header file, to get the benefit
-of @sc{ansi} C prototypes in all the files where the function is called.
-And once you have it, you lose nothing by writing the function
-definition in the pre-@sc{ansi} style.
-
-If you don't know non-@sc{ansi} C, there's no need to learn it; just
-write in @sc{ansi} C.
-
-@node Source Language
-@section Using Languages Other Than C
-
-Using a language other than C is like using a non-standard feature: it
-will cause trouble for users.  Even if GCC supports the other language,
-users may find it inconvenient to have to install the compiler for that
-other language in order to build your program.  For example, if you
-write your program in C++, people will have to install the C++ compiler
-in order to compile your program.  Thus, it is better if you write in C.
-
-But there are three situations when there is no disadvantage in using
-some other language:
-
-@itemize @bullet
-@item
-It is okay to use another language if your program contains an
-interpreter for that language.
-
-For example, if your program links with GUILE, it is ok to write part of
-the program in Scheme or another language supported by GUILE.
-
-@item
-It is okay to use another language in a tool specifically intended for
-use with that language.
-
-This is okay because the only people who want to build the tool will be
-those who have installed the other language anyway.
-
-@item
-If an application is of interest to a narrow community, then perhaps
-it's not important if the application is inconvenient to install.
-@end itemize
-
-C has one other advantage over C++ and other compiled languages: more
-people know C, so more people will find it easy to read and modify the
-program if it is written in C.
+of prototypes in all the files where the function is called.  And once
+you have the declaration, you normally lose nothing by writing the
+function definition in the pre-standard style.
+
+This technique does not work for integer types narrower than @code{int}.
+If you think of an argument as being of a type narrower than @code{int},
+declare it as @code{int} instead.
+
+There are a few special cases where this technique is hard to use.  For
+example, if a function argument needs to hold the system type
+@code{dev_t}, you run into trouble, because @code{dev_t} is shorter than
+@code{int} on some machines; but you cannot use @code{int} instead,
+because @code{dev_t} is wider than @code{int} on some machines.  There
+is no type you can safely use on all machines in a non-standard
+definition.  The only way to support non-standard C and pass such an
+argument is to check the width of @code{dev_t} using Autoconf and choose
+the argument type accordingly.  This may not be worth the trouble.
+
+In order to support pre-standard compilers that do not recognize
+prototypes, you may want to use a preprocessor macro like this:
+
+@example
+/* Declare the prototype for a general external function.  */
+#if defined (__STDC__) || defined (WINDOWSNT)
+#define P_(proto) proto
+#else
+#define P_(proto) ()
+#endif
+@end example
+
+@node Conditional Compilation
+@section Conditional Compilation
+
+When supporting configuration options already known when building your
+program we prefer using @code{if (... )} over conditional compilation,
+as in the former case the compiler is able to perform more extensive
+checking of all possible code paths.
+
+For example, please write
+
+@smallexample
+  if (HAS_FOO)
+    ...
+  else
+    ...
+@end smallexample
+
+instead of:
+
+@smallexample
+  #ifdef HAS_FOO
+    ...
+  #else
+    ...
+  #endif
+@end smallexample
+
+A modern compiler such as GCC will generate exactly the same code in
+both cases, and we have been using similar techniques with good success
+in several projects.
+
+While this is not a silver bullet solving all portability problems,
+following this policy would have saved the GCC project alone many person
+hours if not days per year.
+
+In the case of function-like macros like @code{REVERSIBLE_CC_MODE} in
+GCC which cannot be simply used in @code{if( ...)} statements, there is
+an easy workaround.  Simply introduce another macro
+@code{HAS_REVERSIBLE_CC_MODE} as in the following example:
+
+@smallexample
+  #ifdef REVERSIBLE_CC_MODE
+  #define HAS_REVERSIBLE_CC_MODE 1
+  #else
+  #define HAS_REVERSIBLE_CC_MODE 0
+  #endif
+@end smallexample
 
 @node Program Behavior
 @chapter Program Behavior for All Programs
 
-This @value{CHAPTER} describes how to write robust software. It also
-describes general standards for error messages, the command line interface,
-and how libraries should behave.
+This @value{CHAPTER} describes conventions for writing robust
+software.  It also describes general standards for error messages, the
+command line interface, and how libraries should behave.
 
 @menu
@@ -371 +519 @@
 * Libraries::                   Library behavior
 * Errors::                      Formatting error messages
-* User Interfaces::             Standards for command line interfaces
-* Option Table::                Table of long options.
+* User Interfaces::             Standards about interfaces generally
+* Graphical Interfaces::        Standards for graphical interfaces
+* Command-Line Interfaces::     Standards for command line interfaces
+* Option Table::                Table of long options
 * Memory Usage::                When and how to care about memory needs
+* File Usage::                  Which files to use, and where
 @end menu
 
@@ -379 +530 @@
 @section Writing Robust Programs
 
+@cindex arbitrary limits on data
 Avoid arbitrary limits on the length or number of @emph{any} data
 structure, including file names, lines, files, and symbols, by allocating
@@ -384 +536 @@
 are silently truncated''.  This is not acceptable in a GNU utility.
 
+@cindex @code{NUL} characters
 Utilities reading files should not drop NUL characters, or any other
-nonprinting characters @emph{including those with codes above 0177}.  The
-only sensible exceptions would be utilities specifically intended for
-interface to certain types of printers that can't handle those characters.
-
+nonprinting characters @emph{including those with codes above 0177}.
+The only sensible exceptions would be utilities specifically intended
+for interface to certain types of terminals or printers
+that can't handle those characters.
+Whenever possible, try to make programs work properly with
+sequences of bytes that represent multibyte characters, using encodings
+such as UTF-8 and others.
+
+@cindex error messages
 Check every system call for an error return, unless you know you wish to
 ignore errors.  Include the system error text (from @code{perror} or
@@ -396 +554 @@
 sufficient.
 
+@cindex @code{malloc} return value
+@cindex memory allocation failure
 Check every call to @code{malloc} or @code{realloc} to see if it
 returned zero.  Check @code{realloc} even if you are making the block
@@ -417 +577 @@
 virtual memory, and then try the command again.
 
+@cindex command-line arguments, decoding
 Use @code{getopt_long} to decode arguments, unless the argument syntax
 makes this unreasonable.
@@ -429 +590 @@
 are less likely to work compatibly.  If you need to find all the files
 in a directory, use @code{readdir} or some other high-level interface.
-These will be supported compatibly by GNU.
-
-By default, the GNU system will provide the signal handling functions of
-@sc{BSD} and of @sc{POSIX}.  So GNU software should be written to use
-these.
-
+These are supported compatibly by GNU.
+
+@cindex signal handling
+The preferred signal handling facilities are the BSD variant of
+@code{signal}, and the @sc{posix} @code{sigaction} function; the
+alternative USG @code{signal} interface is an inferior design.
+
+Nowadays, using the @sc{posix} signal functions may be the easiest way
+to make a program portable.  If you use @code{signal}, then on GNU/Linux
+systems running GNU libc version 1, you should include
+@file{bsd/signal.h} instead of @file{signal.h}, so as to get BSD
+behavior.  It is up to you whether to support systems where
+@code{signal} has only the USG behavior, or give up on them.
+
+@cindex impossible conditions
 In error checks that detect ``impossible'' conditions, just abort.
 There is usually no point in printing any message.  These checks
@@ -449 +619 @@
 will see 0 as the status, and it will appear that the program succeeded.
 
+@cindex temporary files
+@cindex @code{TMPDIR} environment variable
 If you make temporary files, check the @code{TMPDIR} environment
 variable; if that variable is defined, use the specified directory
 instead of @file{/tmp}.
 
+In addition, be aware that there is a possible security problem when
+creating temporary files in world-writable directories.  In C, you can
+avoid this problem by creating temporary files in this manner:
+
+@example
+fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0600);
+@end example
+
+@noindent
+or by using the @code{mkstemps} function from libiberty.
+
+In bash, use @code{set -C} to avoid this problem.
+
 @node Libraries
 @section Library Behavior
+@cindex libraries
 
 Try to make library functions reentrant.  If they need to do dynamic
@@ -474 +660 @@
 
 External symbols that are not documented entry points for the user
-should have names beginning with @samp{_}.  They should also contain
-the chosen name prefix for the library, to prevent collisions with
-other libraries.  These can go in the same files with user entry
-points if you like.
+should have names beginning with @samp{_}.  The @samp{_} should be
+followed by the chosen name prefix for the library, to prevent
+collisions with other libraries.  These can go in the same files with
+user entry points if you like.
 
 Static functions and variables can be used as you like and need not
@@ -484 +670 @@
 @node Errors
 @section Formatting Error Messages
+@cindex formatting error messages
+@cindex error messages, formatting
 
 Error messages from compilers should look like this:
@@ -490 +678 @@
 @var{source-file-name}:@var{lineno}: @var{message}
 @end example
+
+@noindent
+If you want to mention the column number, use this format:
+
+@example
+@var{source-file-name}:@var{lineno}:@var{column}: @var{message}
+@end example
+
+@noindent
+Line numbers should start from 1 at the beginning of the file, and
+column numbers should start from 1 at the beginning of the line.  (Both
+of these conventions are chosen for compatibility.)  Calculate column
+numbers assuming that space and all ASCII printing characters have
+equal width, and assuming tab stops every 8 columns.
 
 Error messages from other noninteractive programs should look like this:
@@ -506 +708 @@
 @noindent
 when there is no relevant source file.
+
+If you want to mention the column number, use this format:
+
+@example
+@var{program}:@var{source-file-name}:@var{lineno}:@var{column}: @var{message}
+@end example
 
 In an interactive program (one that is reading commands from a
@@ -523 +731 @@
 
 @node User Interfaces
-@section Standards for Command Line Interfaces
-
+@section Standards for Interfaces Generally
+
+@cindex program name and its behavior
+@cindex behavior, dependent on program's name
 Please don't make the behavior of a utility depend on the name used
 to invoke it.  It is useful sometimes to make a link to a utility
@@ -532 +742 @@
 to select among the alternate behaviors.
 
+@cindex output device and program's behavior
 Likewise, please don't make the behavior of the program depend on the
 type of output device it is used with.  Device independence is an
-important principle of the system's design; do not compromise it
-merely to save someone from typing an option now and then.
+important principle of the system's design; do not compromise it merely
+to save someone from typing an option now and then.  (Variation in error
+message syntax when using a terminal is ok, because that is a side issue
+that people do not depend on.)
 
 If you think one behavior is most useful when the output is to a
@@ -551 +764 @@
 multi-column format.
 
-It is a good idea to follow the @sc{POSIX} guidelines for the
+@node Graphical Interfaces
+@section Standards for Graphical Interfaces
+@cindex graphical user interface
+
+@cindex gtk
+When you write a program that provides a graphical user interface,
+please make it work with X Windows and the GTK toolkit unless the
+functionality specifically requires some alternative (for example,
+``displaying jpeg images while in console mode'').
+
+In addition, please provide a command-line interface to control the
+functionality.  (In many cases, the graphical user interface can be a
+separate program which invokes the command-line program.)  This is
+so that the same jobs can be done from scripts.
+
+@cindex corba
+@cindex gnome
+Please also consider providing a CORBA interface (for use from GNOME), a
+library interface (for use from C), and perhaps a keyboard-driven
+console interface (for use by users from console mode).  Once you are
+doing the work to provide the functionality and the graphical interface,
+these won't be much extra work.
+
+@node Command-Line Interfaces
+@section Standards for Command Line Interfaces
+@cindex command-line interface
+
+@findex getopt
+It is a good idea to follow the @sc{posix} guidelines for the
 command-line options of a program.  The easiest way to do this is to use
 @code{getopt} to parse them.  Note that the GNU version of @code{getopt}
 will normally permit options anywhere among the arguments unless the
-special argument @samp{--} is used.  This is not what @sc{POSIX}
+special argument @samp{--} is used.  This is not what @sc{posix}
 specifies; it is a GNU extension.
 
+@cindex long-named options
 Please define long-named options that are equivalent to the
 single-letter Unix-style options.  We hope to make GNU more user
@@ -577 +819 @@
 among GNU utilities, and fewer idiosyncracies for users to remember.
 
+@cindex standard command-line options
 All programs should support two standard options: @samp{--version}
 and @samp{--help}.
 
 @table @code
+@cindex @samp{--version} option
 @item --version
-This option should direct the program to information about its name,
+This option should direct the program to print information about its name,
 version, origin and legal status, all on standard output, and then exit
 successfully.  Other options and arguments should be ignored once this
 is seen, and the program should not perform its normal function.
 
+@cindex canonical name of a program
+@cindex program's canonical name
 The first line is meant to be easy for a program to parse; the version
 number proper starts after the last space.  In addition, it contains
@@ -659 +905 @@
 line.
 
+Translations of the above lines must preserve the validity of the
+copyright notices (@pxref{Internationalization}).  If the translation's
+character set supports it, the @samp{(C)} should be replaced with the
+copyright symbol, as follows:
+
+@ifinfo 
+(the official copyright symbol, which is the letter C in a circle); 
+@end ifinfo 
+@ifnotinfo 
+@copyright{}
+@end ifnotinfo 
+
+Write the word ``Copyright'' exactly like that, in English.  Do not
+translate it into another language.  International treaties recognize
+the English word ``Copyright''; translations into other languages do not
+have legal significance.
+
+
+@cindex @samp{--help} option
 @item --help
 This option should output brief documentation for how to invoke the
@@ -665 +930 @@
 not perform its normal function.
 
+@cindex address for bug reports
+@cindex bug reports
 Near the end of the @samp{--help} option's output there should be a line
 that says where to mail bug reports.  It should have this format:
@@ -675 +942 @@
 @node Option Table
 @section Table of Long Options
+@cindex long option names
+@cindex table of long options
 
 Here is a table of long options used by GNU programs.  It is surely
 incomplete, but we aim to list all the options that a new program might
 want to be compatible with.  If you use names not already in the table,
-please send @email{gnu@@gnu.org} a list of them, with their
+please send @email{bug-standards@@gnu.org} a list of them, with their
 meanings, so we can update the table.
 
@@ -739 +1008 @@
 @samp{-n} in @code{wdiff}.
 
+@item background
+For server programs, run in the background.
+
 @item backward-search
 @samp{-B} in @code{ctags}.
@@ -862 +1134 @@
 @item dereference-args
 @samp{-D} in @code{du}.
+
+@item device
+Specify an I/O device (special file name).
 
 @item diacritics
@@ -995 +1270 @@
 @samp{-F} in @code{shar}.
 
+@item foreground
+For server programs, run in the foreground;
+in other words, don't do anything special to run the server
+in the background.
+
 @item format
 Used in @code{ls}, @code{time}, and @code{ptx}.
@@ -1039 +1319 @@
 @item hide-control-chars
 @samp{-q} in @code{ls}.
+
+@item html
+In @code{makeinfo}, output HTML.
 
 @item idle
@@ -1099 +1382 @@
 @item info
 @samp{-i}, @samp{-l}, and @samp{-m} in Finger.
+
+@item init-file
+In some programs, specify the name of the file to read as the user's
+init file.
 
 @item initial
@@ -1118 +1405 @@
 @samp{-p} in @code{shar}.
 
+@item iso-8601
+Used in @code{date}
+
 @item jobs
 @samp{-j} in Make.
@@ -1353 +1643 @@
 @samp{-F} in @code{gprof}.
 
+@item options
+@samp{-o} in @code{getopt}, @code{fdlist}, @code{fdmount},
+@code{fdmountd}, and @code{fdumount}.
+
 @item output
 In various programs, specify the output file name.
@@ -1436 +1730 @@
 @item prompt
 @samp{-p} in @code{ed}.
+
+@item proxy
+Specify an HTTP proxy.
 
 @item query-user
@@ -1565 +1862 @@
 @samp{-s} in @code{ls}.
 
+@item socket
+Specify a file descriptor for a network server to use for its socket,
+instead of opening and binding a new socket.  This provides a way to
+run, in a nonpriveledged process, a server that normally needs a
+reserved port number.
+
 @item sort
 Used in @code{ls}.
@@ -1662 +1965 @@
 @item time
 Used in @code{ls} and @code{touch}.
+
+@item timeout
+Specify how long to wait before giving up on some operation.
 
 @item to-stdout
@@ -1755 +2061 @@
 @node Memory Usage
 @section Memory Usage
-
-If it typically uses just a few meg of memory, don't bother making any
+@cindex memory usage
+
+If a program typically uses just a few meg of memory, don't bother making any
 effort to reduce memory usage.  For example, if it is impractical for
 other reasons to operate on files more than a few meg long, it is
@@ -1772 +2079 @@
 core and give a fatal error if @code{malloc} returns zero.
 
+@node File Usage
+@section File Usage
+@cindex file usage
+
+Programs should be prepared to operate when @file{/usr} and @file{/etc}
+are read-only file systems.  Thus, if the program manages log files,
+lock files, backup files, score files, or any other files which are
+modified for internal purposes, these files should not be stored in
+@file{/usr} or @file{/etc}.
+
+There are two exceptions.  @file{/etc} is used to store system
+configuration information; it is reasonable for a program to modify
+files in @file{/etc} when its job is to update the system configuration.
+Also, if the user explicitly asks to modify one file in a directory, it
+is reasonable for the program to store other files in the same
+directory.
+
 @node Writing C
 @chapter Making The Best Use of C
@@ -1782 +2106 @@
 * Comments::                    Commenting Your Work
 * Syntactic Conventions::       Clean Use of C Constructs
-* Names::                       Naming Variables and Functions
+* Names::                       Naming Variables, Functions, and Files
 * System Portability::          Portability between different operating systems
 * CPU Portability::             Supporting the range of CPU types
@@ -1792 +2116 @@
 @node Formatting
 @section Formatting Your Source Code
-
+@cindex formatting source code
+
+@cindex open brace
+@cindex braces, in C source
 It is important to put the open-brace that starts the body of a C
 function in column zero, and avoid putting any other open-brace or
@@ -1814 +2141 @@
 
 @noindent
-or, if you want to use @sc{ansi} C, format the definition like this:
+or, if you want to use Standard C syntax, format the definition like
+this:
 
 @example
@@ -1824 +2152 @@
 @end example
 
-In @sc{ansi} C, if the arguments don't fit nicely on one line,
+In Standard C, if the arguments don't fit nicely on one line,
 split it like this:
 
@@ -1834 +2162 @@
 @end example
 
-For the body of the function, we prefer code formatted like this:
+The rest of this section gives our recommendations for other aspects of
+C formatting style, which is also the default style of the @code{indent}
+program in version 1.2 and newer.  It corresponds to the options
+
+@smallexample
+-nbad -bap -nbc -bbo -bl -bli2 -bls -ncdb -nce -cp1 -cs -di2
+-ndj -nfc1 -nfca -hnl -i2 -ip5 -lp -pcs -psl -nsc -nsob
+@end smallexample
+
+We don't think of these recommendations as requirements, because it
+causes no problems for users if two different programs have different
+formatting styles.
+
+But whatever style you use, please use it consistently, since a mixture
+of styles within one program tends to look ugly.  If you are
+contributing changes to an existing program, please follow the style of
+that program.
+
+For the body of the function, our recommended style looks like this:
 
 @example
@@ -1850 +2196 @@
 @end example
 
+@cindex spaces before open-paren
 We find it easier to read a program when it has spaces before the
 open-parentheses and after the commas.  Especially after the commas.
@@ -1856 +2203 @@
 before an operator, not after one.  Here is the right way:
 
+@cindex expressions, splitting
 @example
 if (foo_this_is_long && bar > win (x, y, z)
@@ -1880 +2228 @@
 Insert extra parentheses so that Emacs will indent the code properly.
 For example, the following indentation looks nice if you do it by hand,
-but Emacs would mess it up:
 
 @example
@@ -1887 +2234 @@
 @end example
 
-But adding a set of parentheses solves the problem:
+@noindent
+but Emacs would alter it.  Adding a set of parentheses produces
+something that looks equally nice, and which Emacs will preserve:
 
 @example
@@ -1904 +2253 @@
 @end example
 
+@cindex formfeed
+@cindex control-L
 Please use formfeed characters (control-L) to divide the program into
 pages at logical places (but not within a function).  It does not matter
@@ -1909 +2260 @@
 page.  The formfeeds should appear alone on lines by themselves.
 
-
 @node Comments
 @section Commenting Your Work
+@cindex commenting
 
 Every program should start with a comment saying briefly what it is for.
@@ -1963 +2314 @@
 @end example
 
+@cindex conditionals, comments for
+@cindex @code{#endif}, commenting
 Every @samp{#endif} should have a comment, except in the case of short
 conditionals (just a few lines) that are not nested.  The comment should
@@ -2004 +2357 @@
 @node Syntactic Conventions
 @section Clean Use of C Constructs
-
-Please explicitly declare all arguments to functions.
-Don't omit them just because they are @code{int}s.
+@cindex syntactic conventions
+
+@cindex implicit @code{int}
+@cindex function argument, declaring
+Please explicitly declare the types of all objects.  For example, you
+should explicitly declare all arguments to functions, and you should
+declare functions to return @code{int} rather than omitting the
+@code{int}.
+
+@cindex compiler warnings
+@cindex @samp{-Wall} compiler option
+Some programmers like to use the GCC @samp{-Wall} option, and change the
+code whenever it issues a warning.  If you want to do this, then do.
+Other programmers prefer not to use @samp{-Wall}, because it gives
+warnings for valid and legitimate code which they do not want to change.
+If you want to do this, then do.  The compiler should be your servant,
+not your master.
 
 Declarations of external functions and functions to appear later in the
@@ -2014 +2381 @@
 functions.
 
+@cindex temporary variables
 It used to be common practice to use the same local variables (with
 names like @code{tem}) over and over for different values within one
@@ -2025 +2393 @@
 Don't use local variables or parameters that shadow global identifiers.
 
+@cindex multiple variables in a line
 Don't declare multiple variables in one declaration that spans lines.
 Start a new declaration on each line, instead.  For example, instead
@@ -2125 +2494 @@
 @end example
 
+@pindex lint
 Don't make the program ugly to placate @code{lint}.  Please don't insert any
 casts to @code{void}.  Zero without a cast is perfectly fine as a null
 pointer constant, except when calling a varargs function.
 
-@node  Names
-@section Naming Variables and Functions
-
+@node Names
+@section Naming Variables, Functions, and Files
+
+@cindex names of variables, functions, and files
 The names of global variables and functions in a program serve as
 comments of a sort.  So don't choose terse names---instead, look for
@@ -2141 +2512 @@
 one context, where (presumably) comments explain their purpose.
 
+Try to limit your use of abbreviations in symbol names.  It is ok to
+make a few abbreviations, explain what they mean, and then use them
+frequently, but don't use lots of obscure abbreviations.
+
 Please use underscores to separate words in a name, so that the Emacs
 word commands can be useful within them.  Stick to lower case; reserve
@@ -2165 +2540 @@
 constants.
 
-Use file names of 14 characters or less, to avoid creating gratuitous
-problems on older System V systems.  You can use the program
-@code{doschk} to test for this.  @code{doschk} also tests for potential
-name conflicts if the files were loaded onto an MS-DOS file
-system---something you may or may not care about.
+@cindex file-name limitations
+@pindex doschk
+You might want to make sure that none of the file names would conflict
+the files were loaded onto an MS-DOS file system which shortens the
+names.  You can use the program @code{doschk} to test for this.
+
+Some GNU programs were designed to limit themselves to file names of 14
+characters or less, to avoid file name conflicts if they are read into
+older System V systems.  Please preserve this feature in the existing
+GNU programs that have it, but there is no need to do this in new GNU
+programs.  @code{doschk} also reports file names longer than 14
+characters.
 
 @node System Portability
 @section Portability between System Types
+@cindex portability, between system types
 
 In the Unix world, ``portability'' refers to porting to different Unix
@@ -2179 +2562 @@
 
 The primary purpose of GNU software is to run on top of the GNU kernel,
-compiled with the GNU C compiler, on various types of @sc{cpu}.  The
-amount and kinds of variation among GNU systems on different @sc{cpu}s
-will be comparable to the variation among Linux-based GNU systems or
-among BSD systems today.  So the kinds of portability that are absolutely
-necessary are quite limited.
-
-But many users do run GNU software on non-GNU Unix or Unix-like systems.
-So supporting a variety of Unix-like systems is desirable, although not
-paramount.
-
+compiled with the GNU C compiler, on various types of @sc{cpu}.  So the
+kinds of portability that are absolutely necessary are quite limited.
+But it is important to support Linux-based GNU systems, since they
+are the form of GNU that is popular.
+
+Beyond that, it is good to support the other free operating systems
+(*BSD), and it is nice to support other Unix-like systems if you want
+to.  Supporting a variety of Unix-like systems is desirable, although
+not paramount.  It is usually not too hard, so you may as well do it.
+But you don't have to consider it an obligation, if it does turn out to
+be hard.
+
+@pindex autoconf
 The easiest way to achieve portability to most Unix-like systems is to
 use Autoconf.  It's unlikely that your program needs to know more
@@ -2198 +2584 @@
 when there is a higher-level alternative (@code{readdir}).
 
+@cindex non-@sc{posix} systems, and portability
 As for systems that are not like Unix, such as MSDOS, Windows, the
-Macintosh, VMS, and MVS, supporting them is usually so much work that it
-is better if you don't.
-
-The planned GNU kernel is not finished yet, but you can tell which
-facilities it will provide by looking at the GNU C Library Manual.  The
-GNU kernel is based on Mach, so the features of Mach will also be
-available.  However, if you use Mach features, you'll probably have
-trouble debugging your program today.
+Macintosh, VMS, and MVS, supporting them is often a lot of work.  When
+that is the case, it is better to spend your time adding features that
+will be useful on GNU and GNU/Linux, rather than on supporting other
+incompatible systems.
+
+It is a good idea to define the ``feature test macro''
+@code{_GNU_SOURCE} when compiling your C files.  When you compile on GNU
+or GNU/Linux, this will enable the declarations of GNU library extension
+functions, and that will usually give you a compiler error message if
+you define the same function names in some other way in your program.
+(You don't have to actually @emph{use} these functions, if you prefer
+to make the program more portable to other systems.)
+
+But whether or not you use these GNU extensions, you should avoid
+using their names for any other meanings.  Doing so would make it hard
+to move your code into other GNU programs.
 
 @node CPU Portability
 @section Portability between @sc{cpu}s
 
+@cindex data types, and portability
+@cindex portability, and data types
 Even GNU systems will differ because of differences among @sc{cpu}
 types---for example, difference in byte ordering and alignment
@@ -2218 +2615 @@
 in GNU.
 
+Similarly, don't make any effort to cater to the possibility that
+@code{long} will be smaller than predefined types like @code{size_t}.
+For example, the following code is ok:
+
+@example
+printf ("size = %lu\n", (unsigned long) sizeof array);
+printf ("diff = %ld\n", (long) (pointer2 - pointer1));
+@end example
+
+1989 Standard C requires this to work, and we know of only one
+counterexample: 64-bit programs on Microsoft Windows IA-64.  We will
+leave it to those who want to port GNU programs to that environment
+to figure out how to do it.
+
+Predefined file-size types like @code{off_t} are an exception: they are
+longer than @code{long} on many platforms, so code like the above won't
+work with them.  One way to print an @code{off_t} value portably is to
+print its digits yourself, one by one.
+
 Don't assume that the address of an @code{int} object is also the
 address of its least-significant byte.  This is false on big-endian
@@ -2232 +2648 @@
 pointers of various types, or between pointers and integers.  On most
 machines, there's no difference anyway.  As for the few machines where
-there is a difference, all of them support @sc{ansi} C, so you can use
-prototypes (conditionalized to be active only in @sc{ansi} C) to make
-the code work on those systems.
+there is a difference, all of them support Standard C prototypes, so you can
+use prototypes (perhaps conditionalized to be active only in Standard C)
+to make the code work on those systems.
 
 In certain cases, it is ok to pass integer and pointer arguments
@@ -2244 +2660 @@
 error (s, a1, a2, a3)
      char *s;
-     int a1, a2, a3;
+     char *a1, *a2, *a3;
 @{
   fprintf (stderr, "error: ");
@@ -2252 +2668 @@
 
 @noindent
-In practice, this works on all machines, and it is much simpler than any
-``correct'' alternative.  Be sure @emph{not} to use a prototype
-for such functions.
-
-However, avoid casting pointers to integers unless you really need to.
-These assumptions really reduce portability, and in most programs they
-are easy to avoid.  In the cases where casting pointers to integers is
-essential---such as, a Lisp interpreter which stores type information as
-well as an address in one word---it is ok to do so, but you'll have to
-make explicit provisions to handle different word sizes.
+In practice, this works on all machines, since a pointer is generally
+the widest possible kind of argument; it is much simpler than any
+``correct'' alternative.  Be sure @emph{not} to use a prototype for such
+functions.
+
+If you have decided to use Standard C, then you can instead define
+@code{error} using @file{stdarg.h}, and pass the arguments along to
+@code{vfprintf}.
+
+@cindex casting pointers to integers
+Avoid casting pointers to integers if you can.  Such casts greatly
+reduce portability, and in most programs they are easy to avoid.  In the
+cases where casting pointers to integers is essential---such as, a Lisp
+interpreter which stores type information as well as an address in one
+word---you'll have to make explicit provisions to handle different word
+sizes.  You will also need to make provision for systems in which the
+normal range of addresses you can get from @code{malloc} starts far away
+from zero.
 
 @node System Functions
 @section Calling System Functions
-
-C implementations differ substantially.  @sc{ansi} C reduces but does not
-eliminate the incompatibilities; meanwhile, many users wish to compile
-GNU software with pre-@sc{ansi} compilers.  This chapter gives
-recommendations for how to use the more or less standard C library
-functions to avoid unnecessary loss of portability.
+@cindex library functions, and portability
+@cindex portability, and library functions
+
+C implementations differ substantially.  Standard C reduces but does
+not eliminate the incompatibilities; meanwhile, many GNU packages still
+support pre-standard compilers because this is not hard to do.  This
+chapter gives recommendations for how to use the more-or-less standard C
+library functions to avoid unnecessary loss of portability.
 
 @itemize @bullet
 @item
-Don't use the value of @code{sprintf}.  It returns the number of
+Don't use the return value of @code{sprintf}.  It returns the number of
 characters written on some systems, but not on all systems.
+
+@item
+Be aware that @code{vfprintf} is not always available.
 
 @item
@@ -2282 +2711 @@
 status code; make sure it cannot ever return an undefined value.
 
+@cindex declaration for system functions
 @item
 Don't declare system functions explicitly.
@@ -2298 +2728 @@
 @item
 If you must declare a system function, don't specify the argument types.
-Use an old-style declaration, not an @sc{ansi} prototype.  The more you
+Use an old-style declaration, not a Standard C prototype.  The more you
 specify about the function, the more likely a conflict.
 
@@ -2320 +2750 @@
 specific to those systems.
 
+@cindex string library functions
 @item
 The string functions require special treatment.  Some Unix systems have
@@ -2330 +2761 @@
 the string functions from the header file in the usual way.
 
-That causes less of a problem than you might think.  The newer @sc{ansi}
+That causes less of a problem than you might think.  The newer standard
 string functions should be avoided anyway because many systems still
 don't support them.  The string functions you can use are these:
@@ -2360 +2791 @@
 You should pick a single pair of names and use it throughout your
 program.  (Nowadays, it is better to choose @code{strchr} and
-@code{strrchr} for new programs, since those are the standard @sc{ansi}
+@code{strrchr} for new programs, since those are the standard
 names.)  Declare both of those names as functions returning @code{char
 *}.  On systems which don't support those names, define them as macros
@@ -2386 +2817 @@
 @node Internationalization
 @section Internationalization
-
+@cindex internationalization
+
+@pindex gettext
 GNU has a library called GNU gettext that makes it easy to translate the
 messages in a program into various languages.  You should use this
@@ -2413 +2846 @@
 package---for example, @samp{fileutils} for the GNU file utilities.
 
+@cindex message text, and internationalization
 To enable gettext to work well, avoid writing code that makes
 assumptions about the structure of words or sentences.  When you want
@@ -2484 +2918 @@
 @node Mmap
 @section Mmap
+@findex mmap
 
 Don't assume that @code{mmap} either works on all files or fails
@@ -2500 +2935 @@
 @node Documentation
 @chapter Documenting Programs
+@cindex documentation
+
+A GNU program should ideally come with full free documentation, adequate
+for both reference and tutorial purposes.  If the package can be
+programmed or extended, the documentation should cover programming or
+extending it, as well as just using it.
 
 @menu
 * GNU Manuals::                 Writing proper manuals.
+* Doc Strings and Manuals::     Compiling doc strings doesn't make a manual.
 * Manual Structure Details::    Specific structure conventions.
+* License for Manuals::         Writing the distribution terms for a manual.
+* Manual Credits::              Giving credit to documentation contributors.
+* Printed Manuals::             Mentioning the printed manual.
 * NEWS File::                   NEWS files supplement manuals.
 * Change Logs::                 Recording Changes
@@ -2514 +2959 @@
 @section GNU Manuals
 
-The preferred way to document part of the GNU system is to write a
-manual in the Texinfo formatting language.  See the Texinfo manual,
-either the hardcopy, or the on-line version available through
-@code{info} or the Emacs Info subsystem (@kbd{C-h i}).
+The preferred document format for the GNU system is the Texinfo
+formatting language.  Every GNU package should (ideally) have
+documentation in Texinfo both for reference and for learners.  Texinfo
+makes it possible to produce a good quality formatted book, using
+@TeX{}, and to generate an Info file.  It is also possible to generate
+HTML output from Texinfo source.  See the Texinfo manual, either the
+hardcopy, or the on-line version available through @code{info} or the
+Emacs Info subsystem (@kbd{C-h i}).
+
+Nowadays some other formats such as Docbook and Sgmltexi can be
+converted automatically into Texinfo.  It is ok to produce the Texinfo
+documentation by conversion this way, as long as it gives good results.
 
 Programmers often find it most natural to structure the documentation
@@ -2546 +2999 @@
 together, we can make the whole subject clearer.
 
-The manual which discusses a program should document all of the
-program's command-line options and all of its commands.  It should give
-examples of their use.  But don't organize the manual as a list of
+The manual which discusses a program should certainly document all of
+the program's command-line options and all of its commands.  It should
+give examples of their use.  But don't organize the manual as a list of
 features.  Instead, organize it logically, by subtopics.  Address the
 questions that a user will ask when thinking about the job that the
@@ -2558 +3011 @@
 should give a good introduction to a beginner reading through from the
 start, and should also provide all the details that hackers want.
+The Bison manual is a good example of this---please take a look at it
+to see what we mean.
 
 That is not as hard as it first sounds.  Arrange each chapter as a
@@ -2571 +3026 @@
 Bison manual provides a good example of how to do this.
 
+To serve as a reference, a manual should have an Index that list all the
+functions, variables, options, and important concepts that are part of
+the program.  One combined Index should do for a short manual, but
+sometimes for a complex package it is better to use multiple indices.
+The Texinfo manual includes advice on preparing good index entries, see
+@ref{Index Entries, , Making Index Entries, texinfo, The GNU Texinfo
+Manual}, and see @ref{Indexing Commands, , Defining the Entries of an
+Index, texinfo, The GNU Texinfo manual}.
+
 Don't use Unix man pages as a model for how to write GNU documentation;
 most of them are terse, badly structured, and give inadequate
-explanation of the underlying concepts.  (There are, of course
-exceptions.)  Also Unix man pages use a particular format which is
+explanation of the underlying concepts.  (There are, of course, some
+exceptions.)  Also, Unix man pages use a particular format which is
 different from what we use in GNU manuals.
+
+Please include an email address in the manual for where to report
+bugs @emph{in the manual}.
 
 Please do not use the term ``pathname'' that is used in Unix
 documentation; use ``file name'' (two words) instead.  We use the term
-``path'' only for search paths, which are lists of file names.
+``path'' only for search paths, which are lists of directory names.
 
 Please do not use the term ``illegal'' to refer to erroneous input to a
 computer program.  Please use ``invalid'' for this, and reserve the term
-``illegal'' for violations of law.
+``illegal'' for activities punishable by law.
+
+@node Doc Strings and Manuals
+@section Doc Strings and Manuals
+
+Some programming systems, such as Emacs, provide a documentation string
+for each function, command or variable.  You may be tempted to write a
+reference manual by compiling the documentation strings and writing a
+little additional text to go around them---but you must not do it.  That
+approach is a fundamental mistake.  The text of well-written
+documentation strings will be entirely wrong for a manual.
+
+A documentation string needs to stand alone---when it appears on the
+screen, there will be no other text to introduce or explain it.
+Meanwhile, it can be rather informal in style.
+
+The text describing a function or variable in a manual must not stand
+alone; it appears in the context of a section or subsection.  Other text
+at the beginning of the section should explain some of the concepts, and
+should often make some general points that apply to several functions or
+variables.  The previous descriptions of functions and variables in the
+section will also have given information about the topic.  A description
+written to stand alone would repeat some of that information; this
+redundance looks bad.  Meanwhile, the informality that is acceptable in
+a documentation string is totally unacceptable in a manual.
+
+The only good way to use documentation strings in writing a good manual
+is to use them as a source of information for writing good text.
 
 @node Manual Structure Details
 @section Manual Structure Details
+@cindex manual structure
 
 The title page of the manual should state the version of the programs or
@@ -2594 +3089 @@
 number for the manual in both of these places.
 
-Each program documented in the manual should should have a node named
+Each program documented in the manual should have a node named
 @samp{@var{program} Invocation} or @samp{Invoking @var{program}}.  This
 node (together with its subnodes, if any) should describe the program's
@@ -2606 +3101 @@
 as the node for this purpose, regardless of the node's actual name.
 
-There will be automatic features for specifying a program name and
-quickly reading just this part of its manual.
+The @samp{--usage} feature of the Info reader looks for such a node
+or menu item in order to find the relevant text, so it is essential
+for every Texinfo file to have one.
 
 If one manual describes several programs, it should have such a node for
-each program described.
+each program described in the manual.
+
+@node License for Manuals
+@section License for Manuals
+@cindex license for manuals
+
+Please use the GNU Free Documentation License for all GNU manuals that
+are more than a few pages long.  Likewise for a collection of short
+documents---you only need one copy of the GNU FDL for the whole
+collection.  For a single short document, you can use a very permissive
+non-copyleft license, to avoid taking up space with a long license.
+
+See @uref{http://www.gnu.org/copyleft/fdl-howto.html} for more explanation
+of how to employ the GFDL.
+
+Note that it is not obligatory to include a copy of the GNU GPL or GNU
+LGPL in a manual whose license is neither the GPL nor the LGPL.  It can
+be a good idea to include the program's license in a large manual; in a
+short manual, whose size would be increased considerably by including
+the program's license, it is probably better not to include it.
+
+@node Manual Credits
+@section Manual Credits
+@cindex credits for manuals
+
+Please credit the principal human writers of the manual as the authors,
+on the title page of the manual.  If a company sponsored the work, thank
+the company in a suitable place in the manual, but do not cite the
+company as an author.
+
+@node Printed Manuals
+@section Printed Manuals
+
+The FSF publishes some GNU manuals in printed form.  To encourage sales
+of these manuals, the on-line versions of the manual should mention at
+the very start that the printed manual is available and should point at
+information for getting it---for instance, with a link to the page
+@url{http://www.gnu.org/order/order.html}.  This should not be included
+in the printed manual, though, because there it is redundant.
+
+It is also useful to explain in the on-line forms of the manual how the
+user can print out the manual from the sources.
 
 @node NEWS File
 @section The NEWS File
+@cindex @file{NEWS} file
 
 In addition to its manual, the package should have a file named
@@ -2628 +3166 @@
 @node Change Logs
 @section Change Logs
+@cindex change logs
 
 Keep a change log to describe all the changes made to program source
@@ -2642 +3181 @@
 * Simple Changes::              
 * Conditional Changes::         
+* Indicating the Part Changed::
 @end menu
 
@@ -2660 +3200 @@
 Another alternative is to record change log information with a version
 control system such as RCS or CVS.  This can be converted automatically
-to a @file{ChangeLog} file.
+to a @file{ChangeLog} file using @code{rcs2log}; in Emacs, the command
+@kbd{C-x v a} (@code{vc-update-change-log}) does the job.
 
 There's no need to describe the full purpose of the changes or how they
@@ -2681 +3222 @@
 @node Style of Change Logs
 @subsection Style of Change Logs
-
-Here are some examples of change log entries:
-
-@example
+@cindex change logs, style
+
+Here are some simple examples of change log entries, starting with the
+header line that says who made the change and when, followed by
+descriptions of specific changes.  (These examples are drawn from Emacs
+and GCC.)
+
+@example
+1998-08-17  Richard Stallman  <rms@@gnu.org>
+
 * register.el (insert-register): Return nil.
 (jump-to-register): Likewise.
@@ -2715 +3262 @@
 name and the asterisk when successive entries are in the same file.
 
+Break long lists of function names by closing continued lines with
+@samp{)}, rather than @samp{,}, and opening the continuation with
+@samp{(} as in this example:
+
+@example
+* keyboard.c (menu_bar_items, tool_bar_items)
+(Fexecute_extended_command): Deal with `keymap' property.
+@end example
+
 @node Simple Changes
 @subsection Simple Changes
@@ -2722 +3278 @@
 
 When you change the calling sequence of a function in a simple fashion,
-and you change all the callers of the function, there is no need to make
-individual entries for all the callers that you changed.  Just write in
-the entry for the function being called, ``All callers changed.''
+and you change all the callers of the function to use the new calling
+sequence, there is no need to make individual entries for all the
+callers that you changed.  Just write in the entry for the function
+being called, ``All callers changed''---like this:
 
 @example
@@ -2744 +3301 @@
 @node Conditional Changes
 @subsection Conditional Changes
+@cindex conditional changes, and change logs
+@cindex change logs, conditional changes
 
 C programs often contain compile-time @code{#if} conditionals.  Many
@@ -2783 +3342 @@
 @end example
 
+@node Indicating the Part Changed
+@subsection Indicating the Part Changed
+
+Indicate the part of a function which changed by using angle brackets
+enclosing an indication of what the changed part does.  Here is an entry
+for a change in the part of the function @code{sh-while-getopts} that
+deals with @code{sh} commands:
+
+@example
+* progmodes/sh-script.el (sh-while-getopts) <sh>: Handle case that
+user-specified option string is empty.
+@end example
+
+
 @node Man Pages
 @section Man Pages
+@cindex man pages
 
 In the GNU project, man pages are secondary.  It is not necessary or
@@ -2831 +3405 @@
 @node Managing Releases
 @chapter The Release Process
+@cindex releasing
 
 Making a release is more than just bundling up your source files in a
@@ -2842 +3417 @@
 @menu
 * Configuration::               How Configuration Should Work
-* Makefile Conventions::        Makefile Conventions
+* Makefile Conventions::        Makefile Conventions
 * Releases::                    Making Releases
 @end menu
@@ -2848 +3423 @@
 @node Configuration
 @section How Configuration Should Work
-
+@cindex program configuration
+
+@pindex configure
 Each GNU distribution should come with a shell script named
 @code{configure}.  This script is given arguments which describe the
@@ -2916 +3493 @@
 would be a valid alias.  For many programs, @samp{vax-dec-ultrix} would
 be an alias for @samp{vax-dec-bsd}, simply because the differences
-between Ultrix and @sc{BSD} are rarely noticeable, but a few programs
+between Ultrix and @sc{bsd} are rarely noticeable, but a few programs
 might need to distinguish them.
 @c Real 4.4BSD now runs on some Suns.
@@ -2923 +3500 @@
 as a subroutine to validate system types and canonicalize aliases.
 
+@cindex optional features, configure-time
 Other options are permitted to specify in more detail the software
 or hardware present on the machine, and include or exclude optional
@@ -2948 +3526 @@
 @c @samp{no} should omit @var{package}, if it is used by default.
 
-Possible values of @var{package} include 
+Possible values of @var{package} include
 @samp{gnu-as} (or @samp{gas}), @samp{gnu-ld}, @samp{gnu-libc},
 @samp{gdb},
-@samp{x}, 
+@samp{x},
 and
 @samp{x-toolkit}.
@@ -2958 +3536 @@
 find certain files.  That is outside the scope of what @samp{--with}
 options are for.
-
-@item --nfp
-The target machine has no floating point processor.
-
-@item --gas
-The target machine assembler is GAS, the GNU assembler.
-This is obsolete; users should use @samp{--with-gnu-as} instead.
-
-@item --x
-The target machine has the X Window System installed.
-This is obsolete; users should use @samp{--with-x} instead.
 @end table
 
@@ -2984 +3551 @@
 have idiosyncratic configuration options.
 
-Packages that perform part of the compilation process may support cross-compilation.
-In such a case, the host and target machines for the program may be
-different.  The @code{configure} script should normally treat the
-specified type of system as both the host and the target, thus producing
-a program which works for the same type of machine that it runs on.
-
-The way to build a cross-compiler, cross-assembler, or what have you, is
-to specify the option @samp{--host=@var{hosttype}} when running
-@code{configure}.  This specifies the host system without changing the
-type of target system.  The syntax for @var{hosttype} is the same as
-described above.
+Packages that perform part of the compilation process may support
+cross-compilation.  In such a case, the host and target machines for the
+program may be different.
+
+The @code{configure} script should normally treat the specified type of
+system as both the host and the target, thus producing a program which
+works for the same type of machine that it runs on.
+
+To configure a cross-compiler, cross-assembler, or what have you, you
+should specify a target different from the host, using the configure
+option @samp{--target=@var{targettype}}.  The syntax for
+@var{targettype} is the same as for the host type.  So the command would
+look like this:
+
+@example
+./configure @var{hosttype} --target=@var{targettype}
+@end example
+
+Programs for which cross-operation is not meaningful need not accept the
+@samp{--target} option, because configuring an entire operating system for
+cross-operation is not a meaningful operation.
 
 Bootstrapping a cross-compiler requires compiling it on a machine other
 than the host it will run on.  Compilation packages accept a
-configuration option @samp{--build=@var{hosttype}} for specifying the
-configuration on which you will compile them, in case that is different
-from the host.
-
-Programs for which cross-operation is not meaningful need not accept the
-@samp{--host} option, because configuring an entire operating system for
-cross-operation is not a meaningful thing.
+configuration option @samp{--build=@var{buildtype}} for specifying the
+configuration on which you will compile them, but the configure script
+should normally guess the build machine type (using
+@file{config.guess}), so this option is probably not necessary.  The
+host and target types normally default from the build type, so in
+bootstrapping a cross-compiler you must specify them both explicitly.
 
 Some programs have ways of configuring themselves automatically.  If
@@ -3019 +3595 @@
 @node Releases
 @section Making Releases
+@cindex packaging
 
 Package the distribution of @code{Foo version 69.96} up in a gzipped tar
@@ -3030 +3607 @@
 and never changed automatically; non-source files are produced from
 source files by programs under the control of the Makefile.
+
+@cindex @file{README} file
+The distribution should contain a file named @file{README} which gives
+the name of the package, and a general description of what it does.  It
+is also good to explain the purpose of each of the first-level
+subdirectories in the package, if there are any.  The @file{README} file
+should either state the version number of the package, or refer to where
+in the package it can be found.
+
+The @file{README} file should refer to the file @file{INSTALL}, which
+should contain an explanation of the installation procedure.
+
+The @file{README} file should also refer to the file which contains the
+copying conditions.  The GNU GPL, if used, should be in a file called
+@file{COPYING}.  If the GNU LGPL is used, it should be in a file called
+@file{COPYING.LIB}.
 
 Naturally, all the source files must be in the distribution.  It is okay
@@ -3055 +3648 @@
 characters long.  Likewise, no file created by building the program
 should have a name longer than 14 characters.  The reason for this is
-that some systems adhere to a foolish interpretation of the POSIX
+that some systems adhere to a foolish interpretation of the @sc{posix}
 standard, and refuse to open a longer name, rather than truncating as
 they did in the past.
@@ -3074 +3667 @@
 distinct.
 
+@cindex @file{texinfo.tex}, in a distribution
 Include in your distribution a copy of the @file{texinfo.tex} you used
 to test print any @file{*.texinfo} or @file{*.texi} files.
@@ -3083 +3677 @@
 other files to get.
 
+@node References
+@chapter References to Non-Free Software and Documentation
+@cindex references to non-free material
+
+A GNU program should not recommend use of any non-free program.  We
+can't stop some people from writing proprietary programs, or stop
+other people from using them, but we can and should avoid helping to
+advertise them to new potential customers.  Proprietary software is a
+social and ethical problem, and the point of GNU is to solve that
+problem.
+
+When a non-free program or system is well known, you can mention it in
+passing---that is harmless, since users who might want to use it
+probably already know about it.  For instance, it is fine to explain
+how to build your package on top of some non-free operating system, or
+how to use it together with some widely used non-free program.
+
+However, you should give only the necessary information to help those
+who already use the non-free program to use your program with
+it---don't give, or refer to, any further information about the
+proprietary program, and don't imply that the proprietary program
+enhances your program, or that its existence is in any way a good
+thing.  The goal should be that people already using the proprietary
+program will get the advice they need about how to use your free
+program, while people who don't already use the proprietary program
+will not see anything to lead them to take an interest in it.
+
+If a non-free program or system is obscure in your program's domain,
+your program should not mention or support it at all, since doing so
+would tend to popularize the non-free program more than it popularizes
+your program.  (You cannot hope to find many additional users among
+the users of Foobar if the users of Foobar are few.)
+
+A GNU package should not refer the user to any non-free documentation
+for free software.  Free documentation that can be included in free
+operating systems is essential for completing the GNU system, so it is
+a major focus of the GNU Project; to recommend use of documentation
+that we are not allowed to use in GNU would undermine the efforts to
+get documentation that we can include.  So GNU packages should never
+recommend non-free documentation.
+
+@node Copying This Manual
+@appendix Copying This Manual
+
+@menu
+* GNU Free Documentation License::  License for copying this manual
+@end menu
+
+@include fdl.texi
+
+@node Index
+@unnumbered Index
+@printindex cp
+
 @contents
 
 @bye
-Local variables:
-update-date-leading-regexp: "@c This date is automagically updated when you save this file:\n@set lastupdate "
-update-date-trailing-regexp: ""
-eval: (load "/gd/gnuorg/update-date.el")
-eval: (add-hook 'write-file-hooks 'update-date)
-End:
+@c Local variables:
+@c eval: (add-hook 'write-file-hooks 'time-stamp)
+@c time-stamp-start: "@set lastupdate "
+@c time-stamp-end: "$"
+@c time-stamp-format: "%:b %:d, %:y"
+@c compile-command: "make just-standards"
+@c End: