「Ruby/FFI/サンプル」の編集履歴（バックアップ）一覧はこちら

「Ruby/FFI/サンプル」(2010/03/18 (木) 17:42:37) の最新版変更点

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samples

**構造体
ffi-0.5.1で確認

-簡単な例
 class XYZ < FFI::Struct
   layout :x, :int,
          :y, :int,
          :z, :int
 end
 
 a = XYZ.new
 p a[:x]
 a[:x] = 3
 p a[:x]

-配列メンバ
 class TestA < FFI::Struct
   layout :a, :int,
          :b, [:int, 3],
          :c, :int
 end
 
 s = TestA.new
 p s[:b][2]
 s[:b][2] = 100
 p s[:b][2]
 s[:c] = 5
 p s[:b][3]

-共用体
 class TestUnion < FFI::Union
   layout :a, :int,
          :b, :char
 end
 
 n = TestUnion.new
 p n[:b]
 n[:a] = 0xff07
 p n[:a]
 p n[:b]

-アラインメント
 class TestB < FFI::Struct
   layout :a, :long_long,
          :b, :char
 end
 
 p TestB.size
 p TestB.align

-文字列
 class TestC < FFI::Struct
   layout :chars, [:char, 16]
 end
 
 tc = TestC.new
 
 p tc[:chars].to_ptr.put_string(0, "0123456789")
 p tc[:chars].to_str
 
 p tc[:chars].to_ptr.put_string(0, "ZZZZZ")
 p tc[:chars].to_str
 
 p tc[:chars].to_ptr.put_bytes(0, "1234567890123456")
 p tc[:chars].to_str

**関数

-Win32 APIの例
 module WinUser
   extend FFI::Library
   ffi_lib 'user32'
   ffi_convention(:stdcall)
   
   MB_OK = 1
   attach_function(:message_box, :MessageBoxA, [:long, :string, :string, :int], :int)
 end
 
 p WinUser.message_box(0, "message", "window caption", WinUser::MB_OK)

-だいたいの流れ
 p lib = FFI::DynamicLibrary.open("user32", 
   FFI::DynamicLibrary::RTLD_LAZY | FFI::DynamicLibrary::RTLD_GLOBAL)
 p function = lib.find_function("MessageBoxA") # FFI::Library::Symbol
 raise FFI::NotFoundError.new(name, lib.name) unless function
 
 args = [:long, :string, :string, :int].map {|a| FFI.find_type(a) }
 ret_type = FFI.find_type(:int)
 p invoker = FFI::Function.new(ret_type, args, function, {:convention => :stdcall})
 raise FFI::NotFoundError.new(name, lib.name) unless invoker
 p r = invoker.call(0, "message", "window caption", 0)

-コールバック (ffi-0.6.3で動作確認。古いバージョンだとダメ)
 require 'ffi'
 
 class Window
   extend FFI::Library
   ffi_lib('user32')
   ffi_convention(:stdcall)
   
   [
     [:ulong, :uintptr_t],
     [:long, :intptr_t],
     [:uintptr_t, :HWND],
     [:ulong, :DWORD],
     [:int, :BOOL],
     [:intptr_t, :LPARAM],
     [:pointer, :LPTSTR],
   ].each {|t| typedef(*t) }
   
   callback(:EnumWindowsProc, [:HWND, :LPARAM], :BOOL)
   attach_function(:EnumWindows, [:EnumWindowsProc, :LPARAM], :BOOL)
   attach_function(:GetWindowTextA, [:HWND, :LPTSTR, :int], :int)
   attach_function(:GetClassNameA, [:HWND, :LPTSTR, :int], :int)
   attach_function(:IsWindowVisible, [:HWND], :BOOL)
   
   class << self
     alias :GetWindowText :GetWindowTextA
     alias :GetClassName :GetClassNameA
   end
   
   def self.each(lparam=0, &block)
     EnumWindows(lparam) {|hwnd, lparam|
       block.call(self.new(hwnd), lparam)
     }
   end
   
   attr_reader :hwnd
   
   def initialize(hwnd)
     @hwnd = hwnd
   end
   
   def title
     pstr = FFI::MemoryPointer.new(1,256)
     self.class.GetWindowText(@hwnd, pstr, pstr.size)
     pstr.read_string
   end
   
   def class_name
     pstr = FFI::MemoryPointer.new(1,256)
     self.class.GetClassName(@hwnd, pstr, pstr.size)
     pstr.read_string
   end
   
   def visible?
     self.class.IsWindowVisible(@hwnd).nonzero?
   end
 end
 
 
 Window.each {|win, lparam|
   puts "#{win.title} [#{win.class_name}]" if win.visible?
   1
 }

samples

**構造体
ffi-0.5.1で確認

-簡単な例
 class XYZ < FFI::Struct
   layout :x, :int,
          :y, :int,
          :z, :int
 end
 
 a = XYZ.new
 p a[:x]
 a[:x] = 3
 p a[:x]

-配列メンバ
 class TestA < FFI::Struct
   layout :a, :int,
          :b, [:int, 3],
          :c, :int
 end
 
 s = TestA.new
 p s[:b][2]
 s[:b][2] = 100
 p s[:b][2]
 s[:c] = 5
 p s[:b][3]

-共用体
 class TestUnion < FFI::Union
   layout :a, :int,
          :b, :char
 end
 
 n = TestUnion.new
 p n[:b]
 n[:a] = 0xff07
 p n[:a]
 p n[:b]

-アラインメント
 class TestB < FFI::Struct
   layout :a, :long_long,
          :b, :char
 end
 
 p TestB.size
 p TestB.align

-文字列
 class TestC < FFI::Struct
   layout :chars, [:char, 16]
 end
 
 tc = TestC.new
 
 p tc[:chars].to_ptr.put_string(0, "0123456789")
 p tc[:chars].to_str
 
 p tc[:chars].to_ptr.put_string(0, "ZZZZZ")
 p tc[:chars].to_str
 
 p tc[:chars].to_ptr.put_bytes(0, "1234567890123456")
 p tc[:chars].to_str

**関数

-Win32 APIの例
 module WinUser
   extend FFI::Library
   ffi_lib 'user32'
   ffi_convention(:stdcall)
   
   MB_OK = 1
   attach_function(:message_box, :MessageBoxA, [:long, :string, :string, :int], :int)
 end
 
 p WinUser.message_box(0, "message", "window caption", WinUser::MB_OK)

-だいたいの流れ
 p lib = FFI::DynamicLibrary.open("user32", 
   FFI::DynamicLibrary::RTLD_LAZY | FFI::DynamicLibrary::RTLD_GLOBAL)
 p function = lib.find_function("MessageBoxA") # FFI::Library::Symbol
 raise FFI::NotFoundError.new(name, lib.name) unless function
 
 args = [:long, :string, :string, :int].map {|a| FFI.find_type(a) }
 ret_type = FFI.find_type(:int)
 p invoker = FFI::Function.new(ret_type, args, function, {:convention => :stdcall})
 raise FFI::NotFoundError.new(name, lib.name) unless invoker
 p r = invoker.call(0, "message", "window caption", 0)

-コールバックの例。ウィンドウの列挙 (ffi-0.6.3で動作確認。古いバージョンだとダメ)
 require 'ffi'
 
 class Window
   extend FFI::Library
   ffi_lib('user32')
   ffi_convention(:stdcall)
   
   [
     [:ulong, :uintptr_t],
     [:long, :intptr_t],
     [:uintptr_t, :HWND],
     [:ulong, :DWORD],
     [:int, :BOOL],
     [:intptr_t, :LPARAM],
     [:pointer, :LPTSTR],
   ].each {|t| typedef(*t) }
   
   callback(:EnumWindowsProc, [:HWND, :LPARAM], :BOOL)
   attach_function(:EnumWindows, [:EnumWindowsProc, :LPARAM], :BOOL)
   attach_function(:GetWindowTextA, [:HWND, :LPTSTR, :int], :int)
   attach_function(:GetClassNameA, [:HWND, :LPTSTR, :int], :int)
   attach_function(:IsWindowVisible, [:HWND], :BOOL)
   
   class << self
     alias :GetWindowText :GetWindowTextA
     alias :GetClassName :GetClassNameA
   end
   
   def self.each(lparam=0, &block)
     EnumWindows(lparam) {|hwnd, lparam|
       block.call(self.new(hwnd), lparam)
     }
   end
   
   attr_reader :hwnd
   
   def initialize(hwnd)
     @hwnd = hwnd
   end
   
   def title
     pstr = FFI::MemoryPointer.new(1,256)
     self.class.GetWindowText(@hwnd, pstr, pstr.size)
     pstr.read_string
   end
   
   def class_name
     pstr = FFI::MemoryPointer.new(1,256)
     self.class.GetClassName(@hwnd, pstr, pstr.size)
     pstr.read_string
   end
   
   def visible?
     self.class.IsWindowVisible(@hwnd).nonzero?
   end
 end
 
 
 Window.each {|win, lparam|
   puts "#{win.title} [#{win.class_name}]" if win.visible?
   1
 }