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.
DEFAULT
A predefined pseudo-handle of RTLD_DEFAULT
Which will find the first occurrence of the desired symbol using the default library search order
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 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 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.
The Fiddle::Handle is the manner to access the dynamic library
Example
Setup
1 2 3 4 | libc_so = "/lib64/libc.so.6"=> "/lib64/libc.so.6"@handle = Fiddle::Handle.new(libc_so)=> #<Fiddle::Handle:0x00000000d69ef8> |
Setup, with flags
1 2 3 4 | 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
1 2 | strcpy_addr = @handle['strcpy']=> 140062278451968 |
or
1 2 | strcpy_addr = @handle.sym('strcpy')=> 140062278451968 |