Manual
Table Of Contents
48
(For example, a funcon in a library to compute square roots has a purpose that is enrely well-dened independent of the applicaon. Therefore, Subsecon
2d requires that any applicaon-supplied funcon or table used by this funcon must be oponal: if the applicaon does not supply it, the square root
funcon must sll compute square roots.)
These requirements apply to the modied work as a whole. If idenable secons 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 secons when you distribute them as
separate works. But when you distribute the same secons as part of a whole which is a work based on the Library, the distribuon of the whole must be on
the terms of this License, whose permissions for other licensees extend to the enre whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this secon to claim rights or contest your rights to work wrien enrely by you; rather, the intent is to exercise the right to control
the distribuon of derivave or collecve works based on the Library.
In addion, mere aggregaon 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
distribuon medium does not bring the other work under the scope of this License.
3. 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 noces 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 noces.
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
derivave works made from that copy.
This opon is useful when you wish to copy part of the code of the Library into a program that is not a library.
4. You may copy and distribute the Library (or a poron or derivave of it, under Secon 2) in object code or executable form under the terms of Secons 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
Secons 1 and 2 above on a medium customarily used for soware interchange.
If distribuon of object code is made by oering access to copy from a designated place, then oering equivalent access to copy the source code from the
same place sases the requirement to distribute the source code, even though third pares are not compelled to copy the source along with the object
code.
5. A program that contains no derivave of any poron 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 isolaon, is not a derivave 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 derivave of the Library (because it contains porons of
the Library), rather than a “work that uses the library”. The executable is therefore covered by this License. Secon 6 states terms for distribuon of such
executables.
When a “work that uses the Library” uses material from a header le that is part of the Library, the object code for the work may be a derivave work of the
Library even though the source code is not. Whether this is true is especially signicant 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 dened by law.
If such an object le uses only numerical parameters, data structure layouts and accessors, and small macros and small inline funcons (ten lines or less
in length), then the use of the object le is unrestricted, regardless of whether it is legally a derivave work. (Executables containing this object code plus
porons of the Library will sll fall under Secon 6.)
Otherwise, if the work is a derivave of the Library, you may distribute the object code for the work under the terms of Secon 6. Any executables containing
that work also fall under Secon 6, whether or not they are linked directly with the Library itself.
6. As an excepon to the Secons above, you may also combine or link a “work that uses the Library” with the Library to produce a work containing porons
of the Library, and distribute that work under terms of your choice, provided that the terms permit modicaon of the work for the customer’s own use and
reverse engineering for debugging such modicaons.
You must give prominent noce 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 execuon displays copyright noces, you must include the copyright noce for the Library among them, as
well as a reference direcng the user to the copy of this License. Also, you must do one of these things:
a) 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 Secons 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 modied executable containing the modied Library. (It is understood that the user
who changes the contents of denions les in the Library will not necessarily be able to recompile the applicaon to use the modied
denions.)
b) Use a suitable shared library mechanism for linking with the Library. A suitable mechanism is one that (1) uses at run me a copy of
the library already present on the user’s computer system, rather than copying library funcons into the executable, and (2) will operate
properly with a modied version of the library, if the user installs one, as long as the modied version is interface-compable with the
version that the work was made with.
c) Accompany the work with a wrien oer, valid for at least three years, to give the same user the materials specied in Subsecon 6a,
above, for a charge no more than the cost of performing this distribuon.
d) If distribuon of the work is made by oering access to copy from a designated place, oer equivalent access to copy the above
specied materials from the same place.
e) Verify that the user has already received a copy of these materials or that you have already sent this user a copy.