This section lists all functions that are available through dynamic link libraries. All external functions declared in a dynamic
link library that are called from the script must be declared before they are used. Use the keyword
dll.
Syntax
DllDecl = "dll" DllName Prototype { Prototype }.
Prototype = ExtFuncName [ @deprecated [ "(" NewFuncName ")" ] ] "function" FuncName
[ "(" ParamList ")" ] [ ":" RetType ].
ParamList = ParamDecl { "," ParamDecl }.
ParamDecl = [ ParamName ":" ] [ PassMode ]
( BDL_Type | C_Type ) { ParamModifier }.
PassMode = "in" | "inout" | "out".
ParamModifier = "allownull" | "explicit" |
"lenspec" | "sizespec" |
"optional"[":=" (signum | float | boolean | ident)].
BDL_Type = "number" | "float" | "string" | "boolean" | "list".
C_Type = "ptr" | "dstring" | "union" | "long" |
"short" | "char" | "unsigned short" |
"unsigned char" | "double".
RetType = "number" | "float" | "string" |
"dstring" | "boolean" | "long" |
"short" | "char" | "unsigned short" |
"unsigned char" | "double".
| Section
|
Description
|
| DllName
|
A constant string that specifies the name of the DLL file that contains the function(s) you want to call
|
| Prototype
|
The definition of the function prototype of a DLL function you want to call
|
| ExtFuncName
|
A constant string that specifies the name of the function as used inside the DLL (case-sensitive)
|
| FuncName
|
An identifier that specifies the name of the function as used inside the
BDL script (case-insensitive)
|
| ParamName
|
An identifier that specifies the name of the parameter (optional).
|
| PassMode
|
Indicates whether the parameter is passed into the function by reference (out and inout) or by value (in). The default is
in. (Optional)
|
| C_Type
|
The data type of a function parameter specified using
C
data types
|
| BDL_Type
|
The data type of a parameter of a function using
BDL data types. The
BDL data types correspond to the
C data types in the table below
|
| RetType
|
The data type of the return value of the function using
BDL data types or
C data types, explained in the table below
|
| BDL data type
|
C data type
|
Description
|
| number
|
long
|
BDL data type number represents a 4-byte signed integer value
|
| float
|
double
|
BDL data type float represents an 8-byte floating point value
|
| string
|
char*
|
BDL data type string represents a null terminated character string value
|
| boolean
|
long
|
BDL data type boolean represents a 4-byte integer value where 1 represents true and 0 represents false
|
The following table shows valid data type combinations between actual parameters (BDL data types) and formal parameters of external functions using
C
data types.
| Actual BDL parameter type
|
Formal BDL parameter type
|
Formal C/C++ parameter type
|
Internal Type (accessible via rtPlugInLib.lib)
|
| number
|
char
|
char
|
TByte1
|
| number
|
unsigned, char
|
unsigned, char
|
TUByte1
|
| number
|
short
|
short
|
TByte2
|
| number
|
unsigned, short
|
unsigned, short
|
TUByte2
|
| number
|
number, long
|
long
|
TByte4
|
| number
|
number, long
|
unsigned, long
|
TUByte4
|
| number
|
number, long, ptr
|
void*
|
TPointer
|
| float
|
float
|
float
|
Real4
|
| float
|
double
|
double
|
Real8
|
| string, in <number>
|
string
|
char*
|
TString
|
| string, in <number>
|
ptr
|
void*
|
TPointer
|
| string, in <number>
|
dstring
|
void*
|
CBdlStr*
|
| boolean
|
boolean
|
int
|
TBool
|
| boolean, number, float, string, boolean[], number[], float[], string[]
|
union
|
void*
|
CBdlUnion*
|
Note: If you use ptr as data type for your external function, the compiler does not perform a type check between actual and formal
parameters. Actual parameters of type number can be passed to DLL functions by reference (default) or by value using the ptr
data type for the formal parameter. To pass an argument by value, preface the argument with the in keyword in the call to
the DLL function.
Note: Functions marked with
@deprecated issue a warning during compiling and highlight the new function to use instead.
Example
dll "odbc32.dll"
"SQLConnect"
function SqlConnect(in number, in string, in number,
in string, in number,
in string, in number): short;
dll "testdll.dll"
"MyStrlen"
function StrLen(inout string): number;
dcltrans
transaction TConnect
const
SQL_NTS := -3;
var
hdbc, retcode : number;
dsn_name : string;
begin
dsn_name := "dsn_sample";
retcode := SqlConnect(hdbc, dsn_name, SQL_NTS, "u1",
SQL_NTS, "u1", SQL_NTS);
end TConnect;