CMPDYLIB(1)CMPDYLIB(1)NAMEcmpdylib - compare two dynamic shared libraries for compatibility
SYNOPSIScmpdylib oldLibrary newLibrary
DESCRIPTIONcmpdylib compares two versions of a dynamic shared library to see if
they are compatible with each other. If the two versions are incompati‐
ble, the reason is printed to stdout, and the exit status is nonzero.
If they are compatible, nothing is printed, and the exit status is
To see if the two versions are compatible, cmpdylib first verifies that
newLibrary was built for all of the architectures that oldLibrary was
built for. If so, for each architecture, it checks to see if the global
symbols defined in oldLibrary are still defined in newLibrary. It then
looks for new symbols, symbols defined in newLibrary that are not
defined in oldLibrary. If it finds new symbols, it compares the com‐
patibility version numbers of the two libraries. If the compatibility
version number of newLibrary is greater than oldLibrary, the libraries
are still compatible. If the compatibility version number is the same
or less, the libraries are incompatible.
The older version of the library.
The newer version of the library.
This example shows the result of performing cmpdylib on two incompati‐
ble versions of the Foundation library. As stated, the versions are
incompatible because the newer version was not built for the ppc archi‐
cmpdylib: file: Foundation_proj/Foundation does not contain architec‐
cmpdylib: new dynamic shared library: Foundation_proj/Foundation does
not contain architecture ppc
The exit status is zero if the library versions are compatible and
nonzero if they are incompatible.
There are lots of other things that could be checked for that are not
(such as the Objective C API).
Apple Computer, Inc. November 3, 1997 CMPDYLIB(1)