.. highlightlang:: us .. index:: RegisterFunction .. _registerfunction: RegisterFunction ================ .. us.tag RegisterFunction ENGLISH Programming.Symboltable Changed420 Changed500 Changed5100 Changed5200 :ref:`RegisterFunction` registers a function from a dynamic link library (DLL) to the UniScript symbol table. After a function is registered, the function can be called directly by UniScript. .. function:: nValue = RegisterFunction(ssDLL, ssExternalName, ssReturnType, ssInternalName, svParamTypes) .. us.return **Return Value** *nValue* is a scalar value greater than 0, if the function was successfully called. In case an error occurred, nValue is one of the following values: .. list-table:: :header-rows: 1 * - Value - Meaning * - -1 - The DLL ssDLL cannot be found or cannot be loaded. * - -2 - The function ssExternalName cannot be found in the DLL. * - -3 - The Parameter ssReturnType is not specified correctly. * - -4 - The Parameter ssInternalName is not specified correctly. * - -5 - The Parameter ssParamTypes is not specified correctly. .. us.params **Parameters** .. uparam:: ssDLL *ssDLL* is the name of the DLL. If the extension is not specified, the function will use the extension :file:`.DLL`. If no path name is specified or associated executable modules must be loaded, the function will search for the DLLs in the following order: * In the UniPlot directory * In the current directory * In the Windows System directory * In the Windows directory * In the directories, specified in the PATH environment variable. Example to add a directory to the PATH environment variable:: ssPath = getenv("path"); putenv("path=" + ssPath + ";" + ssDir); If the DLL is specified with a full path all DLLs which might be loaded by the given DLL must be located in one of the directories specified above. I one of the DLL cannot be accessed the function returns the error value -1. .. uparam:: ssExternalName *ssExternalName* is the external function name. If the name is not found in the DLL, :ref:`RegisterFunction` will return -2. The name is case sensitive. Instead of the name, the ordinal number can be used starting with a # sign, e.g. #123. .. uparam:: ssReturnType *ssReturnType* specifies the return value of the function *ssExternalName*. Possible data types are listed in the table below. In case the function does not return a value, ``"void"`` must be specified. Because functions in UniScript always return a value, UniScript will return 1 for such a function. If the function returns a pointer to a structure, ``"void*"`` can be specified. .. uparam:: ssInternalName *ssInternalName* is the function name used used to call the function from UniScript. The function name must begin with a letter or an underscore, followed by any number of underscores, letters or digits (e.g. ``ThisIsAValidName``). .. uparam:: svParamTypes *svParamTypes* is a vector of strings (number of elements is limited to 32). Each element specifies one data type or the function *ssExternalName*. The following table specifies possible data types. The left column lists the data type of the function in the DLL. The right column lists the corresponding UniScript data types. When a DLL function is called, UniScript will convert the data to the specified type listed in the left column. .. list-table:: :header-rows: 1 * - Value - Meaning * - "void" - "void" is used for the Parameter *ssReturnType*, if the DLL function does not return a value. Because functions in UniScript always return a value, UniScript will return the value 1. "void" for the parameter *svParamTypes* should only be specified if the function does not have any parameter. * - "char" - (1 byte) Real scalar or scalar string with one character. * - "wchar_t" - (2 bytes) Real scalar or scalar string with one unicode character. * - "uchar" - (1 byte) Real scalar or scalar string with one character. * - "short" - (2 bytes) Real scalar. * - "ushort" - (2 bytes) Real scalar. * - "int" - (4 bytes) Real scalar. * - "uint" - (4 bytes) Real scalar. * - "int64" - (8 bytes) Real scalar. * - "uint64" - (8 bytes) Real scalar. * - "size_t" - (4 Bytes or 8 Bytes depending on the UniPlot version. For the 64-bit version of UniPlot the size_t is a "unsigned long long"). * - "intptr_t" - This is the data type for pointers, Size for x86: 4 Bytes, x64: 8 Bytes. * - "float" - (4 bytes) Real scalar. * - "double" - (8 bytes) Real scalar. * - "fcomplex" - (2 \* 4 bytes) Complex scalar. * - "complex" - (16 bytes) Complex scalar. * - "void\*" - Address. * - "char\*" - Address or string scalar. * - "wchar_t\*" - Address oder string skalar. * - "uchar\*" - Address or string scalar. * - "byte\*" - Address of string scalar. * - "short\*" - Address or real vector/matrix. * - "ushort\*" - Address or real vector/matrix. * - "int\*" - Address or real vector/matrix. * - "uint\*" - Address or real vector/matrix. * - "int64\*" - Address or real vector/matrix. * - "uint64\*" - Address or real vector/matrix. * - "float\*" - Address or real vector/matrix. * - "double\*" - Address or real vector/matrix. * - "fcomplex\*" - Complex scalar/vector/matrix. * - "complex\*" - Complex scalar/vector/matrix. .. us.comment **Comment** Caution: The RegisterFunction function can only perform a limited error check. An incorrect call can cause a crash of UniPlot. .. us.example **Example** The following function call registers the function ``FindWinowA`` which is located in the DLL :file:`User32.dll`. After the registration is finished, the function can be called with its UniScript name ``"_FindWindow"``. :: RegisterFunction("USER32",.. "FindWindowA", "uint", .. "_FindWindow", ["char*", "char*"]); Example of ``_FindWindow`` function call. The function returns 0 if Excel is not running. The return value is not equal to 0 if Excel is already running. :: h = _FindWindow("XLMAIN", strempty(1,1)); .. us.comment **Comment** UniPlot 64-bit uses the libffi library - a portable foreign function interface library. This is the copyright notice: .. highlight:: none :: ffi.c - Copyright (c) 1996, 1998, 1999, 2001 Red Hat, Inc. Copyright (c) 2002 Ranjit Mathew Copyright (c) 2002 Bo Thorsen Copyright (c) 2002 Roger Sayle x86 Foreign Function Interface Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ``Software''), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL CYGNUS SOLUTIONS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. .. highlight:: us .. us.history **History** .. list-table:: :header-rows: 1 * - Version - Description * - 5.20.0 - New type "intptr_t". This type can be used for pointers (x86: 4 Bytes, x64: 8 Bytes). * - 5.10.0 - New types "int64", "uint64" and "size_t" * - 5.0.0 - New type "wchar_t". * - 4.2.0 - For *svParamTypes* the new datatype ``byte*`` was added. In opposite to ``char*`` and ``uchar*`` the result will not be truncated at the first "\\x00"-character. .. seealso:: :ref:`loadlib`, :ref:`loadiclib` :sub:`id-30251`