👤
Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:
Select Section of Man Page:
Select Man Page Repository:

Linux 2.6 - man page for dlclose (linux section 3posix)

DLCLOSE(P)			    POSIX Programmer's Manual			       DLCLOSE(P)

NAME
       dlclose - close a dlopen object

SYNOPSIS
       #include <dlfcn.h>

       int dlclose(void *handle);

DESCRIPTION
       The  dlclose()  function  shall	inform	the system that the object referenced by a handle
       returned from a previous dlopen() invocation is no longer needed by the application.

       The use of dlclose() reflects a statement of intent on the part of the process,	but  does
       not create any requirement upon the implementation, such as removal of the code or symbols
       referenced by handle. Once an object has been closed using dlclose() an application should
       assume  that  its symbols are no longer available to dlsym(). All objects loaded automati-
       cally as a result of invoking dlopen() on the referenced object shall also  be  closed  if
       this is the last reference to it.

       Although a dlclose() operation is not required to remove structures from an address space,
       neither is an implementation prohibited from doing so. The  only  restriction  on  such	a
       removal	is that no object shall be removed to which references have been relocated, until
       or unless all such references are removed. For instance, an object that	had  been  loaded
       with  a	dlopen()  operation  specifying  the  RTLD_GLOBAL flag might provide a target for
       dynamic relocations performed in the processing of other objects-in such environments,  an
       application may assume that no relocation, once made, shall be undone or remade unless the
       object requiring the relocation has itself been removed.

RETURN VALUE
       If the referenced object was successfully closed, dlclose() shall return 0. If the  object
       could not be closed, or if handle does not refer to an open object, dlclose() shall return
       a non-zero value. More detailed diagnostic information shall be	available  through  dler-
       ror().

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       The following example illustrates use of dlopen() and dlclose():

	      ...
	      /* Open a dynamic library and then close it ... */

	      #include <dlfcn.h>
	      void *mylib;
	      int eret;

	      mylib = dlopen("mylib.so", RTLD_LOCAL | RTLD_LAZY);
	      ...
	      eret = dlclose(mylib);
	      ...

APPLICATION USAGE
       A  conforming  application should employ a handle returned from a dlopen() invocation only
       within a given scope bracketed by the dlopen() and dlclose()  operations.  Implementations
       are  free  to  use  reference  counting	or  other  techniques such that multiple calls to
       dlopen() referencing the same object may return the same object for  handle.   Implementa-
       tions  are  also  free to reuse a handle. For these reasons, the value of a handle must be
       treated as an opaque object by  the  application,  used	only  in  calls  to  dlsym()  and
       dlclose().

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       dlerror()  ,  dlopen()  ,  dlsym()  , the Base Definitions volume of IEEE Std 1003.1-2001,
       <dlfcn.h>

COPYRIGHT
       Portions of this text are reprinted and	reproduced  in	electronic  form  from	IEEE  Std
       1003.1,	2003  Edition,	Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard, the original IEEE and The Open Group Standard is the referee document. The orig-
       inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group			       2003				       DLCLOSE(P)


All times are GMT -4. The time now is 09:49 AM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password