Class: Fiddle::Handle
- Inherits:
-
Object
- Object
- Fiddle::Handle
- Defined in:
- handle.c,
handle.c
Overview
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
Constant Summary collapse
- 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.
predefined_fiddle_handle(RTLD_NEXT)
- DEFAULT =
A predefined pseudo-handle of RTLD_DEFAULT
Which will find the first occurrence of the desired symbol using the default library search order
predefined_fiddle_handle(RTLD_DEFAULT)
- RTLD_GLOBAL =
:Handle flag.
The symbols defined by this library will be made available for symbol resolution of subsequently loaded libraries.
rtld Fiddle
- RTLD_LAZY =
: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 Fiddle
- RTLD_NOW =
: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.
rtld Fiddle
Class Method Summary collapse
-
.[] ⇒ Object
call-seq: sym(name).
-
.sym ⇒ Object
call-seq: sym(name).
Instance Method Summary collapse
-
#[] ⇒ Object
call-seq: sym(name).
-
#close ⇒ Object
Close this handle.
-
#close_enabled? ⇒ Boolean
Returns
true
if dlclose() will be called when this handle is garbage collected. -
#disable_close ⇒ Object
Disable a call to dlclose() when this handle is garbage collected.
-
#enable_close ⇒ Object
Enable a call to dlclose() when this handle is garbage collected.
-
#new(lib = nil, flags = Fiddle::RTLD_LAZY|Fiddle::RTLD_GLOBAL) ⇒ Object
constructor
Create a new handler that opens library named
lib
withflags
. -
#sym ⇒ Object
call-seq: sym(name).
-
#to_i ⇒ Object
Returns the memory address for this handle.
Constructor Details
#new(lib = nil, flags = Fiddle::RTLD_LAZY|Fiddle::RTLD_GLOBAL) ⇒ Object
Create a new handler that opens library named lib
with flags
. If no library is specified, RTLD_DEFAULT is used.
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# File 'handle.c', line 121
static VALUE
rb_fiddle_handle_initialize(int argc, VALUE argv[], VALUE self)
{
void *ptr;
struct dl_handle *fiddle_handle;
VALUE lib, flag;
char *clib;
int cflag;
const char *err;
switch( rb_scan_args(argc, argv, "02", &lib, &flag) ){
case 0:
clib = NULL;
cflag = RTLD_LAZY | RTLD_GLOBAL;
break;
case 1:
clib = NIL_P(lib) ? NULL : StringValuePtr(lib);
cflag = RTLD_LAZY | RTLD_GLOBAL;
break;
case 2:
clib = NIL_P(lib) ? NULL : StringValuePtr(lib);
cflag = NUM2INT(flag);
break;
default:
rb_bug("rb_fiddle_handle_new");
}
rb_secure(2);
#if defined(_WIN32)
if( !clib ){
HANDLE rb_libruby_handle(void);
ptr = rb_libruby_handle();
}
else if( STRCASECMP(clib, "libc") == 0
# ifdef RUBY_COREDLL
|| STRCASECMP(clib, RUBY_COREDLL) == 0
|| STRCASECMP(clib, RUBY_COREDLL".dll") == 0
# endif
){
# ifdef _WIN32_WCE
ptr = dlopen("coredll.dll", cflag);
# else
ptr = w32_coredll();
# endif
}
else
#endif
ptr = dlopen(clib, cflag);
#if defined(HAVE_DLERROR)
if( !ptr && (err = dlerror()) ){
rb_raise(rb_eFiddleError, "%s", err);
}
#else
if( !ptr ){
err = dlerror();
rb_raise(rb_eFiddleError, "%s", err);
}
#endif
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
if( fiddle_handle->ptr && fiddle_handle->open && fiddle_handle->enable_close ){
dlclose(fiddle_handle->ptr);
}
fiddle_handle->ptr = ptr;
fiddle_handle->open = 1;
fiddle_handle->enable_close = 0;
if( rb_block_given_p() ){
rb_ensure(rb_yield, self, rb_fiddle_handle_close, self);
}
return Qnil;
}
|
Class Method Details
.[] ⇒ Object
call-seq: sym(name)
Get the address as an Integer for the function named name
. The function is searched via dlsym on RTLD_NEXT.
See man(3) dlsym() for more info.
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# File 'handle.c', line 296
static VALUE
rb_fiddle_handle_s_sym(VALUE self, VALUE sym)
{
return fiddle_handle_sym(RTLD_NEXT, StringValueCStr(sym));
}
|
.sym ⇒ Object
call-seq: sym(name)
Get the address as an Integer for the function named name
. The function is searched via dlsym on RTLD_NEXT.
See man(3) dlsym() for more info.
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# File 'handle.c', line 296
static VALUE
rb_fiddle_handle_s_sym(VALUE self, VALUE sym)
{
return fiddle_handle_sym(RTLD_NEXT, StringValueCStr(sym));
}
|
Instance Method Details
#[] ⇒ Object
call-seq: sym(name)
Get the address as an Integer for the function named name
.
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# File 'handle.c', line 266
static VALUE
rb_fiddle_handle_sym(VALUE self, VALUE sym)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
if( ! fiddle_handle->open ){
rb_raise(rb_eFiddleError, "closed handle");
}
return fiddle_handle_sym(fiddle_handle->ptr, StringValueCStr(sym));
}
|
#close ⇒ Object
Close this handle.
Calling close more than once will raise a Fiddle::DLError exception.
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# File 'handle.c', line 63
static VALUE
rb_fiddle_handle_close(VALUE self)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
if(fiddle_handle->open) {
int ret = dlclose(fiddle_handle->ptr);
fiddle_handle->open = 0;
/* Check dlclose for successful return value */
if(ret) {
#if defined(HAVE_DLERROR)
rb_raise(rb_eFiddleError, "%s", dlerror());
#else
rb_raise(rb_eFiddleError, "could not close handle");
#endif
}
return INT2NUM(ret);
}
rb_raise(rb_eFiddleError, "dlclose() called too many times");
UNREACHABLE;
}
|
#close_enabled? ⇒ Boolean
Returns true
if dlclose() will be called when this handle is garbage collected.
See man(3) dlclose() for more info.
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# File 'handle.c', line 232
static VALUE
rb_fiddle_handle_close_enabled_p(VALUE self)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
if(fiddle_handle->enable_close) return Qtrue;
return Qfalse;
}
|
#disable_close ⇒ Object
Disable a call to dlclose() when this handle is garbage collected.
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# File 'handle.c', line 215
static VALUE
rb_fiddle_handle_disable_close(VALUE self)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
fiddle_handle->enable_close = 0;
return Qnil;
}
|
#enable_close ⇒ Object
Enable a call to dlclose() when this handle is garbage collected.
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# File 'handle.c', line 200
static VALUE
rb_fiddle_handle_enable_close(VALUE self)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
fiddle_handle->enable_close = 1;
return Qnil;
}
|
#sym ⇒ Object
call-seq: sym(name)
Get the address as an Integer for the function named name
.
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# File 'handle.c', line 266
static VALUE
rb_fiddle_handle_sym(VALUE self, VALUE sym)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
if( ! fiddle_handle->open ){
rb_raise(rb_eFiddleError, "closed handle");
}
return fiddle_handle_sym(fiddle_handle->ptr, StringValueCStr(sym));
}
|
#to_i ⇒ Object
Returns the memory address for this handle.
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# File 'handle.c', line 248
static VALUE
rb_fiddle_handle_to_i(VALUE self)
{
struct dl_handle *fiddle_handle;
TypedData_Get_Struct(self, struct dl_handle, &fiddle_handle_data_type, fiddle_handle);
return PTR2NUM(fiddle_handle);
}
|