C and Fortran

Julia has a single ccall() function that will run a routine compiled and bundled into a shared object library.

The call has the form

ccall((func,libr),ret_type,(arg1_type,arg2_type, …),arg1, arg2, …)

where the object code for the func function is present in the libr shared library and returns a value of ret_type, followed by an optional tuple of arguments and the actual argument values.

If the library name is omitted, then it defaults to the default Julia library, libjulia, and in this case, the first argument is now specified as a string rather than a tuple.

If necessary, Julia can “find” the library, which usually requires adding it to a library on the LD_LIBRARY_PATH load library path or modifying the latter to contain a new directory.

Note

As of version 1.0+, ccall() may have a function pointer as a first argument.

An alternate, more convenient form, is to use the @ccall macro:

@ccall lib.fun(arg1::arg1_type,arg2...