Add ffi example

ffi.lua

@@ -0,0 +1,31 @@
+local ffi = require "ffi"
+local fs = require "fs"
+
+-- Feed the header to ffi
+ffi.cdef(fs.readFileSync("uvffi.h"))
+-- Cache the C namespace object
+local C = ffi.C
+-- Create our lua module
+local uv = {}
+
+local function uvCheck(err)
+  if err.code == 0 then return end
+  local name = ffi.string(C.uv_err_name(err))
+  local message = ffi.string(C.uv_strerror(err))
+  error(name .. ": " .. message)
+end
+
+function uv.getProcessTitle()
+  local buffer = ffi.new("char[MAX_TITLE_LENGTH]")
+  uvCheck(C.uv_get_process_title(buffer, C.MAX_TITLE_LENGTH))
+  return ffi.string(buffer)
+end
+
+function uv.setProcessTitle(title)
+  uvCheck(C.uv_set_process_title(title))
+end
+
+p(uv.getProcessTitle())
+uv.setProcessTitle("FOOMONKEY")
+p(uv.getProcessTitle())
+

uvffi.h

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+/* uvffi.h */
+enum { MAX_TITLE_LENGTH = 8192 }
+struct uv_err_s { int code; int sys_errno_; };
+typedef struct uv_err_s uv_err_t;
+uv_err_t uv_get_process_title(char* buffer, size_t size);
+uv_err_t uv_set_process_title(const char* title);
+const char* uv_strerror(uv_err_t err);
+const char* uv_err_name(uv_err_t err);