Dylibsymbol

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DyLibSymbol

Returns the address of a function or variable in a dll

Syntax

Declare Function DyLibSymbol ( ByVal libhandle As Any Ptr, ByRef symbol As String ) As Any Ptr
Declare Function DyLibSymbol ( ByVal libhandle As Any Ptr, ByVal symbol As Short ) As Any Ptr

Parameters

• libhandle
• symbol

Description

DyLibSymbol returns a pointer to the variable or function named symbol , in the dll pointed by libhandle. libhandle is obtained by loading the dll with DyLibLoad. The symbol must have been Exported in the dll.
If libhandle is 0, the symbol is searched in the current executable or dll.

If using cdecl functions, only the name of the procedure needs to be specified. If dynamically linking to a function created using STDCALL (default in windows), then the function must be decorated. To decorate a function, use its name, '@', then the number of bytes passed as arguments. For instance if the function FOO takes 3 integer arguments, the decorated function would be 'FOO@12'. Remember, without an explicit Alias, the procedure name will be uppercase.

If linking to a dll created in Visual C++(tm), decoration need not be used. For GCC, decoration is needed.

Note: The dylibsymbol, if failing, will attempt to automatically decorate the procedure, from @0 to @256, in 4 byte increments.

Return Value

A Pointer to the function or variable in the library.

If the function fails, the return value is 0.

Remarks

Usage

result = DyLibSymbol ( libhandle, symbol )

Platform Differences

• Ordinals are not supported on Linux, 0 is always returned.
• Ordinals are not supported on DOS, 0 is always returned.
• Windows does not support DyLibSymbol use with variables (only with procedures).
• DOS: see specific Shared Libraries - DOS page

Dialect Differences

• Not available in the -lang qb dialect unless referenced with the alias __Dylibsymbol.

Differences from QB

• New to FreeBASIC

See also

• DyLibLoad
• DyLibFree
• Export

Examples

See the dynamic loading example on the Shared Libraries page.

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Category: Modularizing
Kind: function

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Reproduced from the FreeBASIC Wiki Manual under the GNU Free Documentation License 1.3 — with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. Copyright © the FreeBASIC project and wiki contributors. See License.