Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

dlclose(3) [osx man page]

DLCLOSE(3)						   BSD Library Functions Manual 						DLCLOSE(3)

dlclose -- close a dynamic library or bundle SYNOPSIS
#include <dlfcn.h> int dlclose(void* handle); DESCRIPTION
dlclose() releases a reference to the dynamic library or bundle referenced by handle. If the reference count drops to 0, the bundle is removed from the address space, and handle is rendered invalid. Just before removing a dynamic library or bundle in this way, any termina- tion routines in it are called. handle is the value returned by a previous call to dlopen. Prior to Mac OS X 10.5, only bundles could be unloaded. Starting in Mac OS X 10.5, dynamic libraries may also be unloaded. There are a cou- ple of cases in which a dynamic library will never be unloaded: 1) the main executable links against it, 2) An API that does not supoort unloading (e.g. NSAddImage()) was used to load it or some other dynnamic library that depends on it, 3) the dynamic library is in dyld's shared cache. RETURN VALUES
If dlclose() is successful, it returns a value of 0. Otherwise it returns -1, and sets an error string that can be retrived with dlerror(). SEE ALSO
dlopen(3) dlsym(3) dlerror(3) dyld(3) ld(1) cc(1) Nov 6, 2006

Check Out this Related Man Page

dlclose(3C)						   Standard C Library Functions 					       dlclose(3C)

dlclose - close a shared object SYNOPSIS
#include <dlfcn.h> int dlclose(void *handle); DESCRIPTION
The dlclose() function decrements the reference count of the supplied handle. This handle represents an executable object file and its dependencies, acquired from a previous call to dlopen(). A handle that is no longer referenced is processed in an attempt to unload any objects that are associated with the handle from the current process. An unreferenced handle is no longer available to dlsym(). Any finalization code within an object is executed prior to that object being unloaded. Any routines registered by an object using atexit(3C) are called prior to that object being unloaded. See NOTES. RETURN VALUES
If the handle was successfully unreferenced, dlclose() returns 0. If the handle is invalid, or an error occurred as a result of unloading an object, dlclose() returns a non-zero value. Additional diagnostic information is available through dlerror(). USAGE
The dlclose() function is one of a family of functions that give the user direct access to the dynamic linking facilities. These facilities are available to dynamically-linked processes only. See the Linker and Libraries Guide. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
ld(1),, atexit(3C), dladdr(3C), dldump(3C), dlerror(3C), dlopen(3C), dlsym(3C), attributes(5), standards(5) Linker and Libraries Guide NOTES
A successful invocation of dlclose() does not guarantee that the objects associated with the handle are removed from the address space of the current process. Objects can be referenced by multiple handles, or by other objects. An object is not removed from the address space of the current process until all references to that object are removed. Once an object has been closed by dlclose(), referencing symbols contained in that object can cause undefined behavior. As part of unloading an object, finalization code within the object is called before the dlclose() returns. This finalization is user code, and as such, can produce errors that can not be caught by dlclose(). For example, an object loaded using RTLD_LAZY that attempts to call a function that can not be located, results in process termination. Erroneous programming practices within the finalization code can also result in process termination. The runtime linkers debugging facility can offer help identifying these types of error. See the LD_DEBUG environment variable of SunOS 5.11 1 March 2004 dlclose(3C)
Man Page