dlerror(3c) [sunos man page]

dlerror(3C)						   Standard C Library Functions 					       dlerror(3C)

NAME

       dlerror - get diagnostic information

SYNOPSIS

       #include <dlfcn.h>

       char *dlerror(void);

DESCRIPTION

       The  dlerror()  function returns a null-terminated character string that describes the last error that occurred during dynamic linking pro-
       cessing. The returned string contains no trailing newline. If no dynamic linking errors have occurred since the last  invocation  of  dler-
       ror(),  dlerror()  returns  NULL.  Thus, invoking  dlerror() a second time, immediately following a prior invocation, results in NULL being
       returned.

USAGE

       The dlerror() 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 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), dladdr(3C), dlclose(3C), dldump(3C), dlopen(3C), dlsym(3C), attributes(5), standards(5)

       Linker and Libraries Guide

NOTES

       The  messages  returned	by  dlerror() can reside in a static buffer that is overwritten on each call to dlerror(). Application code should
       not write to this buffer.  Programs wanting to preserve an error message should make their own copies of that message.

SunOS 5.10							    1 Mar 2004							       dlerror(3C)

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

NAME

       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), ld.so.1(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 ld.so.1(1).

SunOS 5.11							   1 March 2004 						       dlclose(3C)