CMPDYLIB(1)						      General Commands Manual						       CMPDYLIB(1)

NAME

       cmpdylib - compare two dynamic shared libraries for compatibility

SYNOPSIS

       cmpdylib oldLibrary newLibrary

DESCRIPTION

       cmpdylib compares two versions of a dynamic shared library to see if they are compatible with each other. If the two versions are incompat-
       ible, 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.

       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
       compatibility 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.

OPTIONS

       oldLibrary
	      The older version of the library.

       newLibrary
	      The newer version of the library.

EXAMPLES

       This  example  shows  the result of performing 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.

       cmpdylib /System/Library/Frameworks/Foundation.framework/Foundation Foundation_proj/Foundation
       cmpdylib: file: Foundation_proj/Foundation does not contain architecture: ppc
       cmpdylib: new dynamic shared library: Foundation_proj/Foundation  does not contain architecture ppc

DIAGNOSTICS

       The exit status is zero if the library versions are compatible and nonzero if they are incompatible.

BUGS

       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)