clib
The clib
module exposes Blade capabilites to interact with C shared libraries. The workflow follows a simple approach.
- Load the library
- Define the function schematics
- Call the function.
That simple!
For example, the following code dirname()
and cos()
function from the standard C library on a Unix machine (Linux, OSX, FreeBSD etc).
# Import clib
import clib
# 1. Load 'libc' shared module available on Unix systems
var lib = clib.load('libc')
# 2. Declare the functions
var dirname = lib.define('dirname', clib.char_ptr, clib.char_ptr)
var cos = lib.define('cos', clib.double, clib.double) # this may not work on linux
# 3. Call the functions
echo dirname('/path/to/my/file.ext')
echo cos(23)
# Close the library (this is a good practice, but not required)
lib.close()
The first argument to a definiton is the name of the function. The second is its return type. If the function takes parameters, the parameter types follow immediately. (See below for a list of the available types.)
NOT YET SUPPORTED:
- Variadic functions
Properties
- clib.void
- C void type type ptr
- clib.bool
- C bool type type ptr
- clib.uint8_t
- C uint8_t type type ptr
- clib.int8_t
- C int8_t type type ptr
- clib.byte
- C byte type type ptr
- clib.ubyte
- C ubyte type type ptr
- clib.uint16_t
- C uint16_t type type ptr
- clib.int16_t
- C int16_t type type ptr
- clib.uint32_t
- C uint32_t type type ptr
- clib.int32_t
- C int32_t type type ptr
- clib.uint64_t
- C uint64_t type type ptr
- clib.int64_t
- C int64_t type type ptr
- clib.ssize_t
- C ssize_t type type ptr
- clib.float
- C float type type ptr
- clib.double
- C double type type ptr
- clib.uchar
- C uchar type type ptr
- clib.char
- C char type type ptr
- clib.ushort
- C ushort type type ptr
- clib.short
- C short type type ptr
- clib.uint
- C uint type type ptr
- clib.int
- C int type type ptr
- clib.ulong
- C ulong type type ptr
- clib.long
- C long type type ptr
- clib.size_t
- C size_t type type ptr
- clib.long_double
- C long_double type type ptr
- clib.char_ptr
- C char_ptr type type ptr
- clib.uchar_ptr
- C uchar_ptr type type ptr
- clib.ptr
- C ptr type type ptr
Functions
- clib.load(name: string)
- Loads a new C shared library pointed to by name. Name must be a relative path, absolute path or the name of a system library. If the system shared library extension is omitted in the name, it will be automatically added. return CLib
- clib.new(type: type, …any)
- Creates a new C value for the specified clib type with the given values. returns bytes
- clib.get(type: type, data: string | bytes)
- Returns the data contained in a C type type encoded in the data. The data should either be an output of
clib.new()
or a call to a function returning one of struct, union or array.For structures created with
named_struct()
, a dictionary will automatically be returned with the values mapped to the names of the structure elements.returns list | dictionary
- clib.get_ptr_index(pointer: ptr, type: clib_type, index: number)
- Get the value at the given index of a pointer based on the given CLib type. return any
- clib.get_ptr_index(pointer: ptr, type: clib_type, index: number, value: any)
- Sets the value at the given index of a pointer based on the given CLib type to the given value. return any
- clib.struct(…type)
- Returns a type that can be used to declare structs. To create or read value for the struct you need to use the
new()
andget()
functions respectively. Alternatively, you may use thepack()
andunpack()
function in thestruct
module respectively.- This function can also be used to define a C union or array.
return type
- clib.named_struct(types: dictionary)
- Returns a type that can be used to declare structs based on the named types. The function works well with the
get()
function because it automatically assigns the name of the struct elements when getting the value.To create or read value for the struct you need to use the
new()
andget()
functions respectively. Alternatively, you may use thepack()
andunpack()
function in thestruct
module respectively.- This function can also be used to define a C union or array.
return type
Classes
class Clib
class CLib provides an interface for interacting with C shared modules.
class Clib methods
- CLib([name: string])
- The name should follow the same practice outlined in
load()
.constructor - load(name: string)
- Loads a new C shared library pointed to by name. Name must be a relative path, absolute path or the name of a system library. If the system shared library extension is omitted in the name, it will be automatically added except on Linux machines. return CLib
- close()
- Closes the handle to the shared library.
- function(name: string)
- Retrieves the handle to a specific function in the shared library. return ptr
- define(name: string, return_type: type, …type)
- Defines a new C function with the given name and return type.
- When there are no more argument, it is declared that the function takes no argument.
define()
expects a list of the argument/parameter types as expected by the function.
E.g.
define('myfunc', int, int, ptr)
Corresponds to the C declaration:
int myfunc(int a, void *b);
- get_pointer()
- Returns a pointer to the underlying module return ptr