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class · Ruby 3.3

Fiddle::Handle

< Object 10 instance methods 4 class methods

The Fiddle::Handle is the manner to access the dynamic library

Example

Setup

libc_so = "/lib64/libc.so.6"
=> "/lib64/libc.so.6"
@handle = Fiddle::Handle.new(libc_so)
=> #<Fiddle::Handle:0x00000000d69ef8>

Setup, with flags

libc_so = "/lib64/libc.so.6"
=> "/lib64/libc.so.6"
@handle = Fiddle::Handle.new(libc_so, Fiddle::RTLD_LAZY | Fiddle::RTLD_GLOBAL)
=> #<Fiddle::Handle:0x00000000d69ef8>

See RTLD_LAZY and RTLD_GLOBAL

Addresses to symbols

strcpy_addr = @handle['strcpy']
=> 140062278451968

or

strcpy_addr = @handle.sym('strcpy')
=> 140062278451968

Class methods 4

.[] .new .sym .sym_defined?

Instance methods 10

#[] #close #close_enabled? #disable_close #enable_close #file_name #sym #sym_defined? #to_i #to_ptr
Constants

DEFAULT

DEFAULT

A predefined pseudo-handle of RTLD_DEFAULT

Which will find the first occurrence of the desired symbol using the default library search order

NEXT

NEXT

A predefined pseudo-handle of RTLD_NEXT

Which will find the next occurrence of a function in the search order after the current library.

RTLD_GLOBAL

RTLD_GLOBAL

rtld Fiddle::Handle flag.

The symbols defined by this library will be made available for symbol resolution of subsequently loaded libraries.

RTLD_LAZY

RTLD_LAZY

rtld Fiddle::Handle flag.

Perform lazy binding. Only resolve symbols as the code that references them is executed. If the symbol is never referenced, then it is never resolved. (Lazy binding is only performed for function references; references to variables are always immediately bound when the library is loaded.)

RTLD_NOW

RTLD_NOW

rtld Fiddle::Handle flag.

If this value is specified or the environment variable LD_BIND_NOW is set to a nonempty string, all undefined symbols in the library are resolved before Fiddle.dlopen returns. If this cannot be done an error is returned.