xref: /aosp_15_r20/external/libconfig/doc/LGPL.texi (revision 2e9d491483b805f09ea864149eadd5680efcc72a)

@c \input texinfo.tex    @c -*-texinfo-*-
@c
@c %**start of header

@c All text is ignored before the setfilename.
@setfilename LGPL.info

@center GNU LESSER GENERAL PUBLIC LICENSE
@center Version 2.1, February 1999

@sp 1

Copyright @copyright{} 1991, 1999 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.

[This is the first released version of the Lesser GPL.  It also counts
as the successor of the GNU Library Public License, version 2, hence the
version number 2.1.]

@sp 1
@center Preamble
@sp 1

The licenses for most software are designed to take away your freedom to
share and change it.  By contrast, the GNU General Public Licenses are
intended to guarantee your freedom to share and change free software--to
make sure the software is free for all its users.

This license, the Lesser General Public License, applies to some
specially designated software packages--typically libraries--of the Free
Software Foundation and other authors who decide to use it.  You can use
it too, but we suggest you first think carefully about whether this
license or the ordinary General Public License is the better strategy to
use in any particular case, based on the explanations below.

When we speak of free software, we are referring to freedom of use, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish); that you receive source code or can get it if
you want it; that you can change the software and use pieces of it in
new free programs; and that you are informed that you can do these
things.

To protect your rights, we need to make restrictions that forbid
distributors to deny you these rights or to ask you to surrender these
rights.  These restrictions translate to certain responsibilities for
you if you distribute copies of the library or if you modify it.

For example, if you distribute copies of the library, whether gratis or
for a fee, you must give the recipients all the rights that we gave you.
You must make sure that they, too, receive or can get the source code.
If you link other code with the library, you must provide complete
object files to the recipients, so that they can relink them with the
library after making changes to the library and recompiling it.  And you
must show them these terms so they know their rights.

We protect your rights with a two-step method: (1) we copyright the
library, and (2) we offer you this license, which gives you legal
permission to copy, distribute and/or modify the library.

To protect each distributor, we want to make it very clear that there is
no warranty for the free library.  Also, if the library is modified by
someone else and passed on, the recipients should know that what they
have is not the original version, so that the original author's
reputation will not be affected by problems that might be introduced by
others.

Finally, software patents pose a constant threat to the existence of any
free program.  We wish to make sure that a company cannot effectively
restrict the users of a free program by obtaining a restrictive license
from a patent holder.  Therefore, we insist that any patent license
obtained for a version of the library must be consistent with the full
freedom of use specified in this license.

Most GNU software, including some libraries, is covered by the ordinary
GNU General Public License.  This license, the GNU Lesser General Public
License, applies to certain designated libraries, and is quite different
from the ordinary General Public License.  We use this license for
certain libraries in order to permit linking those libraries into
non-free programs.

When a program is linked with a library, whether statically or using a
shared library, the combination of the two is legally speaking a
combined work, a derivative of the original library.  The ordinary
General Public License therefore permits such linking only if the entire
combination fits its criteria of freedom.  The Lesser General Public
License permits more lax criteria for linking other code with the
library.

We call this license the ``Lesser'' General Public License because it does
Less to protect the user's freedom than the ordinary General Public
License.  It also provides other free software developers Less of an
advantage over competing non-free programs.  These disadvantages are the
reason we use the ordinary General Public License for many libraries.
However, the Lesser license provides advantages in certain special
circumstances.

For example, on rare occasions, there may be a special need to encourage
the widest possible use of a certain library, so that it becomes a
de-facto standard.  To achieve this, non-free programs must be allowed
to use the library.  A more frequent case is that a free library does
the same job as widely used non-free libraries.  In this case, there is
little to gain by limiting the free library to free software only, so we
use the Lesser General Public License.

In other cases, permission to use a particular library in non-free
programs enables a greater number of people to use a large body of free
software.  For example, permission to use the GNU C Library in non-free
programs enables many more people to use the whole GNU operating system,
as well as its variant, the GNU/Linux operating system.

Although the Lesser General Public License is Less protective of the
users' freedom, it does ensure that the user of a program that is linked
with the Library has the freedom and the wherewithal to run that program
using a modified version of the Library.

The precise terms and conditions for copying, distribution and
modification follow.  Pay close attention to the difference between a
``work based on the library'' and a ``work that uses the library''.  The
former contains code derived from the library, whereas the latter must
be combined with the library in order to run.

@page

@center GNU LESSER GENERAL PUBLIC LICENSE
@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

@enumerate 0

@sp 1
@item
This License Agreement applies to any software library or other program
which contains a notice placed by the copyright holder or other
authorized party saying it may be distributed under the terms of this
Lesser General Public License (also called ``this License'').  Each
licensee is addressed as ``you''.

A ``library'' means a collection of software functions and/or data
prepared so as to be conveniently linked with application programs
(which use some of those functions and data) to form executables.

The ``Library'', below, refers to any such software library or work which
has been distributed under these terms.  A ``work based on the Library''
means either the Library or any derivative work under copyright law:
that is to say, a work containing the Library or a portion of it, either
verbatim or with modifications and/or translated straightforwardly into
another language.  (Hereinafter, translation is included without
limitation in the term ``modification''.)

``Source code'' for a work means the preferred form of the work for making
modifications to it.  For a library, complete source code means all the
source code for all modules it contains, plus any associated interface
definition files, plus the scripts used to control compilation and
installation of the library.

Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope.  The act of running
a program using the Library is not restricted, and output from such a
program is covered only if its contents constitute a work based on the
Library (independent of the use of the Library in a tool for writing
it).  Whether that is true depends on what the Library does and what the
program that uses the Library does.

@sp 1
@item
You may copy and distribute verbatim copies of the Library's complete
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the notices
that refer to this License and to the absence of any warranty; and
distribute a copy of this License along with the Library.

You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.

@sp 1
@item
You may modify your copy or copies of the Library or any portion of it,
thus forming a work based on the Library, and copy and distribute such
modifications or work under the terms of Section 1 above, provided that
you also meet all of these conditions:

@enumerate a

@item
The modified work must itself be a software library.

@sp 1
@item
You must cause the files modified to carry prominent notices stating
that you changed the files and the date of any change.

@sp 1
@item
You must cause the whole of the work to be licensed at no charge to all
third parties under the terms of this License.

@sp 1
@item
If a facility in the modified Library refers to a function or a table of
data to be supplied by an application program that uses the facility,
other than as an argument passed when the facility is invoked, then you
must make a good faith effort to ensure that, in the event an
application does not supply such function or table, the facility still
operates, and performs whatever part of its purpose remains meaningful.

(For example, a function in a library to compute square roots has a
purpose that is entirely well-defined independent of the application.
Therefore, Subsection 2d requires that any application-supplied function
or table used by this function must be optional: if the application does
not supply it, the square root function must still compute square
roots.)

@end enumerate

These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Library, and
can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based on
the Library, the distribution of the whole must be on the terms of this
License, whose permissions for other licensees extend to the entire
whole, and thus to each and every part regardless of who wrote it.

Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Library.

In addition, mere aggregation of another work not based on the Library
with the Library (or with a work based on the Library) on a volume of a
storage or distribution medium does not bring the other work under the
scope of this License.

@sp 1
@item
You may opt to apply the terms of the ordinary GNU General Public
License instead of this License to a given copy of the Library.  To do
this, you must alter all the notices that refer to this License, so that
they refer to the ordinary GNU General Public License, version 2,
instead of to this License.  (If a newer version than version 2 of the
ordinary GNU General Public License has appeared, then you can specify
that version instead if you wish.)  Do not make any other change in
these notices.

Once this change is made in a given copy, it is irreversible for that
copy, so the ordinary GNU General Public License applies to all
subsequent copies and derivative works made from that copy.

This option is useful when you wish to copy part of the code of the
Library into a program that is not a library.

@sp 1
@item
You may copy and distribute the Library (or a portion or derivative of
it, under Section 2) in object code or executable form under the terms
of Sections 1 and 2 above provided that you accompany it with the
complete corresponding machine-readable source code, which must be
distributed under the terms of Sections 1 and 2 above on a medium
customarily used for software interchange.

If distribution of object code is made by offering access to copy from a
designated place, then offering equivalent access to copy the source
code from the same place satisfies the requirement to distribute the
source code, even though third parties are not compelled to copy the
source along with the object code.

@sp 1
@item
A program that contains no derivative of any portion of the Library, but
is designed to work with the Library by being compiled or linked with
it, is called a ``work that uses the Library''.  Such a work, in
isolation, is not a derivative work of the Library, and therefore falls
outside the scope of this License.

However, linking a ``work that uses the Library'' with the Library creates
an executable that is a derivative of the Library (because it contains
portions of the Library), rather than a ``work that uses the library''.
The executable is therefore covered by this License.  Section 6 states
terms for distribution of such executables.

When a ``work that uses the Library'' uses material from a header file
that is part of the Library, the object code for the work may be a
derivative work of the Library even though the source code is not.
Whether this is true is especially significant if the work can be linked
without the Library, or if the work is itself a library.  The threshold
for this to be true is not precisely defined by law.

If such an object file uses only numerical parameters, data structure
layouts and accessors, and small macros and small inline functions (ten
lines or less in length), then the use of the object file is
unrestricted, regardless of whether it is legally a derivative work.
(Executables containing this object code plus portions of the Library
will still fall under Section 6.)

Otherwise, if the work is a derivative of the Library, you may
distribute the object code for the work under the terms of Section 6.
Any executables containing that work also fall under Section 6, whether
or not they are linked directly with the Library itself.

@sp 1
@item
As an exception to the Sections above, you may also combine or link a
``work that uses the Library'' with the Library to produce a work
containing portions of the Library, and distribute that work under terms
of your choice, provided that the terms permit modification of the work
for the customer's own use and reverse engineering for debugging such
modifications.

You must give prominent notice with each copy of the work that the
Library is used in it and that the Library and its use are covered by
this License.  You must supply a copy of this License.  If the work
during execution displays copyright notices, you must include the
copyright notice for the Library among them, as well as a reference
directing the user to the copy of this License.  Also, you must do one
of these things:

@enumerate a

@sp 1
@item
Accompany the work with the complete corresponding machine-readable
source code for the Library including whatever changes were used in the
work (which must be distributed under Sections 1 and 2 above); and, if
the work is an executable linked with the Library, with the complete
machine-readable ``work that uses the Library'', as object code and/or
source code, so that the user can modify the Library and then relink to
produce a modified executable containing the modified Library.  (It is
understood that the user who changes the contents of definitions files
in the Library will not necessarily be able to recompile the application
to use the modified definitions.)

@sp 1
@item
Use a suitable shared library mechanism for linking with the Library.  A
suitable mechanism is one that (1) uses at run time a copy of the
library already present on the user's computer system, rather than
copying library functions into the executable, and (2) will operate
properly with a modified version of the library, if the user installs
one, as long as the modified version is interface-compatible with the
version that the work was made with.

@sp 1
@item
Accompany the work with a written offer, valid for at least three years,
to give the same user the materials specified in Subsection 6a, above,
for a charge no more than the cost of performing this distribution.

@sp 1
@item
If distribution of the work is made by offering access to copy from a
designated place, offer equivalent access to copy the above specified
materials from the same place.

@sp 1
@item
Verify that the user has already received a copy of these materials or
that you have already sent this user a copy.

@end enumerate

For an executable, the required form of the ``work that uses the Library''
must include any data and utility programs needed for reproducing the
executable from it.  However, as a special exception, the materials to
be distributed need not include anything that is normally distributed
(in either source or binary form) with the major components (compiler,
kernel, and so on) of the operating system on which the executable runs,
unless that component itself accompanies the executable.

It may happen that this requirement contradicts the license restrictions
of other proprietary libraries that do not normally accompany the
operating system.  Such a contradiction means you cannot use both them
and the Library together in an executable that you distribute.

@sp 1
@item
You may place library facilities that are a work based on the Library
side-by-side in a single library together with other library facilities
not covered by this License, and distribute such a combined library,
provided that the separate distribution of the work based on the Library
and of the other library facilities is otherwise permitted, and provided
that you do these two things:

@enumerate a

@sp 1
@item
Accompany the combined library with a copy of the same work based on the
Library, uncombined with any other library facilities.  This must be
distributed under the terms of the Sections above.

@sp 1
@item
Give prominent notice with the combined library of the fact that part of
it is a work based on the Library, and explaining where to find the
accompanying uncombined form of the same work.

@end enumerate

@sp 1
@item
You may not copy, modify, sublicense, link with, or distribute the
Library except as expressly provided under this License.  Any attempt
otherwise to copy, modify, sublicense, link with, or distribute the
Library 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.

@sp 1
@item
You are not required to accept this License, since you have not signed
it.  However, nothing else grants you permission to modify or distribute
the Library or its derivative works.  These actions are prohibited by
law if you do not accept this License.  Therefore, by modifying or
distributing the Library (or any work based on the Library), you
indicate your acceptance of this License to do so, and all its terms and
conditions for copying, distributing or modifying the Library or works
based on it.

@sp 1
@item
Each time you redistribute the Library (or any work based on the
Library), the recipient automatically receives a license from the
original licensor to copy, distribute, link with or modify the Library
subject to these terms and conditions.  You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties with
this License.

@sp 1
@item
If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Library at all.  For example, if a patent license
would not permit royalty-free redistribution of the Library by all those
who receive copies directly or indirectly through you, then the only way
you could satisfy both it and this License would be to refrain entirely
from distribution of the Library.

If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply, and the section as a whole is intended to apply in other
circumstances.

It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system which is implemented
by public license practices.  Many people have made generous
contributions to the wide range of software distributed through that
system in reliance on consistent application of that system; it is up to
the author/donor to decide if he or she is willing to distribute
software through any other system and a licensee cannot impose that
choice.

This section is intended to make thoroughly clear what is believed to be
a consequence of the rest of this License.

@sp 1
@item
If the distribution and/or use of the Library is restricted in certain
countries either by patents or by copyrighted interfaces, the original
copyright holder who places the Library under this License may add an
explicit geographical distribution limitation excluding those countries,
so that distribution is permitted only in or among countries not thus
excluded.  In such case, this License incorporates the limitation as if
written in the body of this License.

@sp 1
@item
The Free Software Foundation may publish revised and/or new versions of
the Lesser General Public 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.

Each version is given a distinguishing version number.  If the Library
specifies a version number of this License which applies to it and ``any
later version'', you have the option of following the terms and
conditions either of that version or of any later version published by
the Free Software Foundation.  If the Library does not specify a license
version number, you may choose any version ever published by the Free
Software Foundation.

@sp 1
@item
If you wish to incorporate parts of the Library into other free programs
whose distribution conditions are incompatible with these, write to the
author to ask for permission.  For software which is copyrighted by the
Free Software Foundation, write to the Free Software Foundation; we
sometimes make exceptions for this.  Our decision will be guided by the
two goals of preserving the free status of all derivatives of our free
software and of promoting the sharing and reuse of software generally.

@sp 1
@center NO WARRANTY
@sp 1

@item
BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE LIBRARY ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE LIBRARY IS WITH
YOU.  SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR OR CORRECTION.

@sp 1
@item
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU FOR
DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL
DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE LIBRARY
(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED
INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF
THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR
OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

@end enumerate

@sp 1
@center END OF TERMS AND CONDITIONS
@sp 1
@page
@center How to Apply These Terms to Your New Libraries

If you develop a new library, and you want it to be of the greatest
possible use to the public, we recommend making it free software that
everyone can redistribute and change.  You can do so by permitting
redistribution under these terms (or, alternatively, under the terms of
the ordinary General Public License).

To apply these terms, attach the following notices to the library.  It
is safest to attach them to the start of each source file to most
effectively convey the exclusion of warranty; and each file should have
at least the ``copyright'' line and a pointer to where the full notice is
found.

@format
@t{
<one line to give the library's name and a brief idea of what it does.>
Copyright (C) <year>  <name of author>

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
}
@end format

Also add information on how to contact you by electronic and paper mail.

You should also get your employer (if you work as a programmer) or your
school, if any, to sign a ``copyright disclaimer'' for the library, if
necessary.  Here is a sample; alter the names:

@format
@t{
Yoyodyne, Inc., hereby disclaims all copyright interest in the
library `Frob' (a library for tweaking knobs) written by James Random Hacker.

<signature of Ty Coon>, 1 April 1990
Ty Coon, President of Vice
}
@end format

That's all there is to it!

@c @bye