.TH CMPDYLIB 1 "November 3, 1997" "Apple Computer, Inc." .SH NAME cmpdylib \- compare two dynamic shared libraries for compatibility .SH SYNOPSIS .B cmpdylib .I oldLibrary .I newLibrary .SH DESCRIPTION .B cmpdylib compares two versions of a dynamic shared library to see if they are compatible with each other. If the two versions are incompatible, the reason is printed to stdout, and the exit status is nonzero. If they are compatible, nothing is printed, and the exit status is zero. .PP To see if the two versions are compatible, .B cmpdylib first verifies that .I newLibrary was built for all of the architectures that .I oldLibrary was built for. If so, for each architecture, it checks to see if the global symbols defined in .I oldLibrary are still defined in .I newLibrary. It then looks for new symbols, symbols defined in .I newLibrary that are not defined in .I oldLibrary. If it finds new symbols, it compares the compatibility version numbers of the two libraries. If the compatibility version number of .I newLibrary is greater than .IR oldLibrary , the libraries are still compatible. If the compatibility version number is the same or less, the libraries are incompatible. .SH OPTIONS .TP .I oldLibrary The older version of the library. .TP .I newLibrary The newer version of the library. .SH EXAMPLES This example shows the result of performing .B cmpdylib on two incompatible versions of the Foundation library. As stated, the versions are incompatible because the newer version was not built for the ppc architecture. .PP cmpdylib /System/Library/Frameworks/Foundation.framework/Foundation Foundation_proj/Foundation .br cmpdylib: file: Foundation_proj/Foundation does not contain architecture: ppc .br cmpdylib: new dynamic shared library: Foundation_proj/Foundation does not contain architecture ppc .SH DIAGNOSTICS The exit status is zero if the library versions are compatible and nonzero if they are incompatible. .SH BUGS There are lots of other things that could be checked for that are not (such as the Objective C API).