How to send uint8_t array from C to GO

Question

I want to send uint8_t array from C to GO, but whene i send my array like pointer, i don't know how i can read it and save it in GO like byte[] array :

package main
/*
#include <stdint.h>

uint8_t Plaintext[16] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};

uint8_t * send_data( )
   {
     return  Plaintext;
   }

*/
import "C"
import "unsafe"
import "fmt"

func main() {

    data := [16]byte{}
    p := C.send_data()
    //already try  data = C.send_data()
    fmt.Println(p)
    data = p // don't know how do this ?

}

The objectif is to have data byte array in go like :

data[16] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f}

i try lot of solution, but every time i have log that say " cannot use (func literal)() (type *_Ctype_uchar) as type"uint8" or "byte" ...

Thanks guys for your help !

Answer 1

I want to send uint8_t array from C to Go [and as an array or a slice]

---

For your example,

package main

/*
#include <stdint.h>

uint8_t Plaintext[16] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};

uint8_t *send_data( ) {
    return  Plaintext;
}
*/
import "C"

import (
    "fmt"
    "math"
    "unsafe"
)

func main() {
    // your example
    data := (*[16]byte)(unsafe.Pointer(C.send_data()))
    fmt.Printf("\n%T:\n%d %d : %v\n", data, len(data), cap(data), *data)

    // array example
    const c = 16 // array length is constant
    a := (*[c]byte)(unsafe.Pointer(C.send_data()))
    fmt.Printf("\n%T:\n%d %d : %v\n", a, len(a), cap(a), *a)

    // slice example
    var v = 16 // slice length is variable
    var s []byte
    const vmax = math.MaxInt32 / unsafe.Sizeof(s[0])
    s = (*[vmax]byte)(unsafe.Pointer(C.send_data()))[:v:v]
    fmt.Printf("\n%T:\n%d %d : %v\n", s, len(s), cap(s), s)
}

Output:

[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]

*[16]uint8:
16 16 : [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]

[]uint8:
16 16 : [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]