dlsym

Loads a C/Fortran symbol for an dynamic library.

📝 Syntax

• f = dlsym(lib, symbol_name, return_type, params_types)

📥 Input argument

• lib - a dllib handle.

• symbolname - a string: symbol to load.

• return_type - a string: return type of the C/Fortran function.

• params_types - a cell of strings: arguments using a special syntax with differents data types.

📤 Output argument

• f - a dlsym handle.

📄 Description

dlsym retrieves the address of an exported function as an dlsym handle.

ifsymbolname not found, nelson try to find symbol equivalent based on these rules and in this order:

_symbolname

symbolname

symbolname_

_symbolname_

_SYMBOLNAME

SYMBOLNAME

SYMBOLNAME_

_SYMBOLNAME_

symbol name used is available in prototype field of the returned handle.

If multiple symbol names found, an error is raised with possible names.

Warning: Uses wrong datatype definitions a foreign function can terminate unexpectedly.

💡 Examples

lib = dlopen(modulepath('dynamic_link', 'builtin'));
V = double([1 2;3 4]);
% C prototype:
% int dynlibTestMultiplyDoubleArrayWithReturn(double *x, int size)
f = dlsym(lib, 'dynlibTestMultiplyDoubleArrayWithReturn', 'int32', {'doublePtr', 'int32'});
[r1, r2] = dlcall(f, V, int32(numel(V)))
delete(f);
delete(lib);

Call C getpid function

run([modulepath('dynamic_link'), '/examples/call_c.m']);

Call fortran DASUM (blas) function

run([modulepath('dynamic_link'), '/examples/call_fortran.m']);

🔗 See also

dlcall, C/Nelson equivalent data types.

🕔 History

Version	📄 Description
1.0.0	initial version