Module

A libffi wrapper for Ruby.

Description

Fiddle is an extension to translate a foreign function interface (FFI) with ruby.

It wraps libffi, a popular C library which provides a portable interface that allows code written in one language to call code written in another language.

Example

Here we will use Fiddle::Function to wrap floor(3) from libm

require 'fiddle'

libm = Fiddle.dlopen('/lib/libm.so.6')

floor = Fiddle::Function.new(
  libm['floor'],
  [Fiddle::TYPE_DOUBLE],
  Fiddle::TYPE_DOUBLE
)

puts floor.call(3.14159) #=> 3.0
Constants

TYPE_VOID

C type - void

TYPE_VOIDP

C type - void*

TYPE_CHAR

C type - char

TYPE_SHORT

C type - short

TYPE_INT

C type - int

TYPE_LONG

C type - long

TYPE_LONG_LONG

C type - long long

TYPE_FLOAT

C type - float

TYPE_DOUBLE

C type - double

TYPE_SIZE_T

C type - size_t

TYPE_SSIZE_T

C type - ssize_t

TYPE_PTRDIFF_T

C type - ptrdiff_t

TYPE_INTPTR_T

C type - intptr_t

TYPE_UINTPTR_T

C type - uintptr_t

ALIGN_VOIDP

The alignment size of a void*

ALIGN_CHAR

The alignment size of a char

ALIGN_SHORT

The alignment size of a short

ALIGN_INT

The alignment size of an int

ALIGN_LONG

The alignment size of a long

ALIGN_LONG_LONG

The alignment size of a long long

ALIGN_FLOAT

The alignment size of a float

ALIGN_DOUBLE

The alignment size of a double

ALIGN_SIZE_T

The alignment size of a size_t

ALIGN_SSIZE_T

The alignment size of a ssize_t

ALIGN_PTRDIFF_T

The alignment size of a ptrdiff_t

ALIGN_INTPTR_T

The alignment size of a intptr_t

ALIGN_UINTPTR_T

The alignment size of a uintptr_t

Returns a boolean regarding whether the host is WIN32

SIZEOF_VOIDP

size of a void*

SIZEOF_CHAR

size of a char

SIZEOF_SHORT

size of a short

SIZEOF_INT

size of an int

SIZEOF_LONG

size of a long

SIZEOF_LONG_LONG

size of a long long

SIZEOF_FLOAT

size of a float

SIZEOF_DOUBLE

size of a double

SIZEOF_SIZE_T

size of a size_t

SIZEOF_SSIZE_T

size of a ssize_t

SIZEOF_PTRDIFF_T

size of a ptrdiff_t

SIZEOF_INTPTR_T

size of a intptr_t

SIZEOF_UINTPTR_T

size of a uintptr_t

RUBY_FREE

Address of the ruby_xfree() function

BUILD_RUBY_PLATFORM

Platform built against (i.e. “x86_64-linux”, etc.)

See also RUBY_PLATFORM

Add constants for backwards compat

No documentation available
No documentation available
Class Methods

Creates a new handler that opens library, and returns an instance of Fiddle::Handle.

If nil is given for the library, Fiddle::Handle::DEFAULT is used, which is the equivalent to RTLD_DEFAULT. See man 3 dlopen for more.

lib = Fiddle.dlopen(nil)

The default is dependent on OS, and provide a handle for all libraries already loaded. For example, in most cases you can use this to access libc functions, or ruby functions like rb_str_new.

See Fiddle::Handle.new for more.

Returns the hexadecimal representation of a memory pointer address addr

Example:

lib = Fiddle.dlopen('/lib64/libc-2.15.so')
=> #<Fiddle::Handle:0x00000001342460>

lib['strcpy'].to_s(16)
=> "7f59de6dd240"

Fiddle.dlunwrap(Fiddle.dlwrap(lib['strcpy'].to_s(16)))
=> "7f59de6dd240"

Returns a memory pointer of a function’s hexadecimal address location val

Example:

lib = Fiddle.dlopen('/lib64/libc-2.15.so')
=> #<Fiddle::Handle:0x00000001342460>

Fiddle.dlwrap(lib['strcpy'].to_s(16))
=> 25522520

Free the memory at address addr

Returns the last Error of the current executing Thread or nil if none

Sets the last Error of the current executing Thread to error

Allocate size bytes of memory and return the integer memory address for the allocated memory.

Change the size of the memory allocated at the memory location addr to size bytes. Returns the memory address of the reallocated memory, which may be different than the address passed in.

Returns the last win32 Error of the current executing Thread or nil if none

Sets the last win32 Error of the current executing Thread to error

Instance Methods

Creates a new handler that opens library, and returns an instance of Fiddle::Handle.

If nil is given for the library, Fiddle::Handle::DEFAULT is used, which is the equivalent to RTLD_DEFAULT. See man 3 dlopen for more.

lib = Fiddle.dlopen(nil)

The default is dependent on OS, and provide a handle for all libraries already loaded. For example, in most cases you can use this to access libc functions, or ruby functions like rb_str_new.

See Fiddle::Handle.new for more.