Just another update

Task/Call-a-foreign-language-function/Lua/call-a-foreign-language-function.lua

@@ -0,0 +1,14 @@
+local ffi = require("ffi")
+ffi.cdef[[
+char * strndup(const char * s, size_t n);
+int strlen(const char *s);
+]]
+
+local s1 = "Hello, world!"
+print("Original: " .. s1)
+local s_s1 = ffi.C.strlen(s1)
+print("strlen: " .. s_s1)
+
+local s2 = ffi.string(ffi.C.strndup(s1, s_s1), s_s1)
+print("Copy: " .. s2)
+print("strlen: " .. ffi.C.strlen(s2))

Task/Call-a-foreign-language-function/Mercury/call-a-foreign-language-function-1.mercury

@@ -9,7 +9,7 @@
 :- implementation.
 
 % The actual FFI code begins here.
-:- pragma foreign_decl("C", "char *strdup(const char *s);").
+:- pragma foreign_decl("C", "#include <string.h>").
 
 :- func strdup(string::in) = (string::out) is det.
 :- pragma foreign_proc("C", strdup(S::in) = (SD::out),