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\input texinfo  @c -*-texinfo-*-

@c %**start of header

@setfilename libiberty.info

@settitle @sc{gnu} libiberty

@c %**end of header

@syncodeindex fn cp

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@c %**end of header

@dircategory GNU libraries

@direntry

* Libiberty: (libiberty).          Library of utility functions which

                                   are missing or broken on some systems.

@end direntry

@macro libib

@code{libiberty}

@end macro

@ifinfo

This manual describes the GNU @libib library of utility subroutines.

Copyright @copyright{} 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

2009, 2010 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 1.3

      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''.

@ignore

Permission is granted to process this file through TeX and print the

results, provided the printed document carries a 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

@end ifinfo

@titlepage

@title @sc{gnu} libiberty

@author Phil Edwards et al.

@page

@vskip 0pt plus 1filll

Copyright @copyright{} 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

2009, 2010 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 1.3

      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

@contents

@page

@ifnottex

@node    Top,Using,,

@top     Introduction

The @libib{} library is a collection of subroutines used by various

GNU programs.  It is available under the Library General Public

License; for more information, see @ref{Library Copying}.

@end ifnottex

@menu

* Using::              How to use libiberty in your code.

* Overview::           Overview of available function groups.

* Functions::          Available functions, macros, and global variables.

* Obstacks::           Object Stacks.

* Licenses::           The various licenses under which libiberty sources are

                       distributed.

* Index::              Index of functions and categories.

@end menu

@node Using

@chapter Using

@cindex using libiberty

@cindex libiberty usage

@cindex how to use

@c THIS SECTION IS CRAP AND NEEDS REWRITING BADLY.

To date, @libib{} is generally not installed on its own.  It has evolved

over years but does not have its own version number nor release schedule.

Possibly the easiest way to use @libib{} in your projects is to drop the

@libib{} code into your project's sources, and to build the library along

with your own sources; the library would then be linked in at the end.  This

prevents any possible version mismatches with other copies of libiberty

elsewhere on the system.

Passing @option{--enable-install-libiberty} to the @command{configure}

script when building @libib{} causes the header files and archive library

to be installed when @kbd{make install} is run.  This option also takes

an (optional) argument to specify the installation location, in the same

manner as @option{--prefix}.

For your own projects, an approach which offers stability and flexibility

is to include @libib{} with your code, but allow the end user to optionally

choose to use a previously-installed version instead.  In this way the

user may choose (for example) to install @libib{} as part of GCC, and use

that version for all software built with that compiler.  (This approach

has proven useful with software using the GNU @code{readline} library.)

Making use of @libib{} code usually requires that you include one or more

header files from the @libib{} distribution.  (They will be named as

necessary in the function descriptions.)  At link time, you will need to

add @option{-liberty} to your link command invocation.

@node Overview

@chapter Overview

Functions contained in @libib{} can be divided into three general categories.

@menu

* Supplemental Functions::       Providing functions which don't exist

                                 on older operating systems.

* Replacement Functions::        These functions are sometimes buggy or

                                 unpredictable on some operating systems.

* Extensions::                   Functions which provide useful extensions

                                 or safety wrappers around existing code.

@end menu

@node Supplemental Functions

@section Supplemental Functions

@cindex supplemental functions

@cindex functions, supplemental

@cindex functions, missing

Certain operating systems do not provide functions which have since

become standardized, or at least common.  For example, the Single

Unix Specification Version 2 requires that the @code{basename}

function be provided, but an OS which predates that specification

might not have this function.  This should not prevent well-written

code from running on such a system.

Similarly, some functions exist only among a particular ``flavor''

or ``family'' of operating systems.  As an example, the @code{bzero}

function is often not present on systems outside the BSD-derived

family of systems.

Many such functions are provided in @libib{}.  They are quickly

listed here with little description, as systems which lack them

become less and less common.  Each function @var{foo} is implemented

in @file{@var{foo}.c} but not declared in any @libib{} header file; more

comments and caveats for each function's implementation are often

available in the source file.  Generally, the function can simply

be declared as @code{extern}.

@node Replacement Functions

@section Replacement Functions

@cindex replacement functions

@cindex functions, replacement

Some functions have extremely limited implementations on different

platforms.  Other functions are tedious to use correctly; for example,

proper use of @code{malloc} calls for the return value to be checked and

appropriate action taken if memory has been exhausted.  A group of

``replacement functions'' is available in @libib{} to address these issues

for some of the most commonly used subroutines.

All of these functions are declared in the @file{libiberty.h} header

file.  Many of the implementations will use preprocessor macros set by

GNU Autoconf, if you decide to make use of that program.  Some of these

functions may call one another.

@menu

* Memory Allocation::            Testing and handling failed memory

                                   requests automatically.

* Exit Handlers::                Calling routines on program exit.

* Error Reporting::              Mapping errno and signal numbers to

                                   more useful string formats.

@end menu

@node Memory Allocation

@subsection Memory Allocation

@cindex memory allocation

The functions beginning with the letter @samp{x} are wrappers around

standard functions; the functions provided by the system environment

are called and their results checked before the results are passed back

to client code.  If the standard functions fail, these wrappers will

terminate the program.  Thus, these versions can be used with impunity.

@node Exit Handlers

@subsection Exit Handlers

@cindex exit handlers

The existence and implementation of the @code{atexit} routine varies

amongst the flavors of Unix.  @libib{} provides an unvarying dependable

implementation via @code{xatexit} and @code{xexit}.

@node Error Reporting

@subsection Error Reporting

@cindex error reporting

These are a set of routines to facilitate programming with the system

@code{errno} interface.  The @libib{} source file @file{strerror.c}

contains a good deal of documentation for these functions.

@c signal stuff

@node Extensions

@section Extensions

@cindex extensions

@cindex functions, extension

@libib{} includes additional functionality above and beyond standard

functions, which has proven generically useful in GNU programs, such as

obstacks and regex.  These functions are often copied from other

projects as they gain popularity, and are included here to provide a

central location from which to use, maintain, and distribute them.

@menu

* Obstacks::                     Stacks of arbitrary objects.

@end menu

@c This is generated from the glibc manual using a make-obstacks-texi.sh

@c script of Phil's.  Hope it's accurate.

@include obstacks.texi

@node Functions

@chapter Function, Variable, and Macro Listing.

@include functions.texi

@node Licenses

@appendix Licenses

@menu

* Library Copying::   The GNU Library General Public License

* BSD::               Regents of the University of California

@end menu

@c This takes care of Library Copying.  It is the copying-lib.texi from the

@c GNU web site, with its @node line altered to make makeinfo shut up.

@include copying-lib.texi

@page

@node BSD

@appendixsec BSD

Copyright @copyright{} 1990 Regents of the University of California.

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions

are met:

@enumerate

@item

Redistributions of source code must retain the above copyright

notice, this list of conditions and the following disclaimer.

@item

Redistributions in binary form must reproduce the above copyright

notice, this list of conditions and the following disclaimer in the

documentation and/or other materials provided with the distribution.

@item

[rescinded 22 July 1999]

@item

Neither the name of the University nor the names of its contributors

may be used to endorse or promote products derived from this software

without specific prior written permission.

@end enumerate

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

SUCH DAMAGE.

@node Index

@unnumbered Index

@printindex cp

@bye