Nifty is an interface generator that allows you to use C modules from Erlang.

Web page: [http://parapluu.github.io/nifty/]

Let's say we have two C files mylib.h and mylib.c which we want to use in our Erlang application:

/* mylib.h */
extern int fib(int n);

/* mylib.c */
int
fib(int n) {
  if (n<=2) {
    return 1;
  } else {
    return fib(n-1) + fib(n-2);
  }
}

We can generate a NIF interface and use it from from Erlang with the following command:

nifty:compile("mylib.h", mylib,
              nifty_utils:add_sources(["mylib.c"], [])).
5 = mylib:fib(5).

compiler/3 reads as the first argument a header or interface file and tries to generate an interface for all specified functions. The second argument specifies the Erlang module the interface is about to use and the third argument is used for additional options. These option are compatible with the ones rebar uses to compile NIF modules. In fact, Nifty uses rebar to compile the generated interface.

After successfully cloning enter the following commands

make

and include Nifty in your ERL_LIBS path.

Run the following command to check that everything works correct:

make tests

Make sure, that you have included PropEr in your ERL_LIBS path.

• libclang including the header files
• clang compiler
• PropEr for the unit tests

• unions, enums and function pointers are not supported.
• So far there is no support for anonymous struct.
• Functions using unsupported types will not be translated and a warning is returned.
• Variable arguments of functions (va_list or ...) is not supported. If va_list as type is used, Nifty will print a warning. If ... is used, then the function is translated without the variable arguments: *int printf(const char format, ...) will be translated into printf/1
• The header files must be self contained which limits the usage of incomplete types.
• There is currently no nice way of using arrays although nifty:mem_alloc/1 and nifty:mem_read/1 allow basic usage.
• Nifty has not been tested under Windows.