(* mosml/src/dynlibs/crypt/crypt.sml -- foreign function interface   The SML side of things: how to load and call the C function.  *) (* 1. Load the Dynlib and FileSys structures from the Moscow ML library: *) app load ["Dynlib", "FileSys"]; (* 2. Load the C dynamic library libcrypt.so, and get a handle to it.      Use the absolute path because libcrypt.so is not a system DLL:     *) val dlh = Dynlib.dlopen { lib = Path.concat(FileSys.getDir (), "libcrypt.so"),			  flag = Dynlib.RTLD_LAZY, 			  global = false } (* 3. Get a handle to the C function ml_crypt defined in libcrypt.so:    *) val crypthandle = Dynlib.dlsym dlh "ml_crypt"; (* 4. Define an SML function using this handle and a fixed salt.        The type ascription is necessary for SML type safety:              *) fun crypt (key : string) : string =     Dynlib.app2 crypthandle key "AB"; val _ = print "\nNow invoke the SML crypt function: crypt \"blah\" ...\n\n";