The interface defined in this section allows the user to load shared
libraries (.so files on most Unix systems, .dll
files on Windows). This interface is portable to Windows as well as to
Unix machines providing dlopen(2) (Solaris, Linux,
FreeBSD, Irix and many more) or shl_open(2) (HP/UX). It
is advised to use the predicates from section
12.2.3 in your application.
- open_shared_object(+File,
-Handle)
- File is the name of a shared object file (DLL in
MS-Windows). This file is attached to the current process, and
Handle is unified with a handle to the library. Equivalent to
open_shared_object(File, Handle, []). See also
open_shared_object/3, load_foreign_library/1
and use_foreign_library/1.
On errors, an exception shared_object(Action, Message)
is raised. Message is the return value from dlerror().
- open_shared_object(+File,
-Handle, +Options)
- As open_shared_object/2,
but allows for additional flags to be passed. Defined options are below.
These options map to
RTLD_NOW,
RTLD_LAZY, RTLD_GLOBAL, RTLD_NODELETE,
RTLD_NOLOAD and RTLD_DEEPBIND on systems where
this predicate is implemented using dlopen() and these flags are
supported. If the flag is not supported on the target OS, the
corresponding option is silently ignored.
- resolve(Atom)
- When to resolve symbols. Values are
lazy (default) or
now.
- visibility(Atom)
- Visibility of the new symbols. Values are are
local
(default) or global, making the new symbols available to
all subsequently loaded shared objects.
- now(Bool)
now(true) is the same as resolve(now).
Provided for backward compatibility.- global(Bool)
global(true) is the same as visibility(global).
Provided for backward compatibility.- delete(Bool)
- If
false, include RTLD_NODELETE.
- load(Bool)
- if
false, include RTLD_NOLOAD. This returns a
handle to the object if it is already loaded and NULL
otherwise. It causes this predicate to fail silently if the
object is not loaded.
- deepbind(Bool)
- if
true, include RTLD_DEEPBIND.
Note that these flags may not be supported by your operating system.
Check the documentation of dlopen() or equivalent on your
operating system. Unsupported flags are silently ignored.
- close_shared_object(+Handle)
- Detach the shared object identified by Handle.
- call_shared_object_function(+Handle,
+Function)
- Call the named function in the loaded shared library. The function is
called without arguments and the return value is ignored. Normally this
function installs foreign language predicates using calls to
PL_register_foreign().
