External Interfaces/API Reference

libisloaded

Determine if external library is loaded

Syntax

• libisloaded('libname')
  libisloaded libname
  

Description

libisloaded('libname') returns true if the shared library libname is loaded and false otherwise.

libisloaded libname is the command format for this function.

If you used an alias when initially loading the library, then you must use that alias for the libname argument.

Examples

Example 1

Load the shrlibsample library and check to see if the load was successful before calling one of its functions:

• addpath([matlabroot '\extern\examples\shrlib'])
  loadlibrary shrlibsample.dll shrlibsample.h
  
  if libisloaded('shrlibsample')
     x = calllib('shrlibsample', 'addDoubleRef', 1.78, 5.42, 13.3)
  end
  

Since the library is successfully loaded, the call to addDoubleRef works as expected and returns

• x =
     20.5000
  
  unloadlibrary shrlibsample
  

Example 2

Load the same library, this time giving it an alias. If you use libisloaded with the library name, shrlibsample, it now returns false. Since you loaded the library using an alias, all further references to the library must also use that alias:

• addpath([matlabroot '\extern\examples\shrlib'])
  loadlibrary shrlibsample.dll shrlibsample.h alias lib
  
  libisloaded shrlibsample
  ans =
       0
  
  libisloaded lib
  ans =
       1
  
  unloadlibrary lib
  

See Also

loadlibrary, libfunctions, libfunctionsview, libpointer, libstruct, calllib, unloadlibrary

libfunctionsview

libpointer