字符串到 char (*array)[]

Question

//file.go

func main() {

  message := "My Message :)"

  // I've tried this slice before.

  // tmpslice := (*[1 << 30]*C.char)(unsafe.Pointer(argv))[:length:length] 

  argv := make([]*C.char, len(message))

  for i, s := range str {

    cs := C.CString(string(s))

    defer C.free(unsafe.Pointer(cs))

    argv[i] = cs

  }

  C.notifyWebhook(&argv)

}

  //file.c

  void notiftWebhook(char (*message)[]) {

  printf("notiftWebhook executed | argv: %s \n", *message);

  char url[500];

  char data[200];

  int user_id = 0xdeadfeed;

  snprintf(url,500,"https://webhook.site/a6a8d1ae-6766-4d90-a4c8-87a9599bfbf0",token);

  snprintf(data,200,"user_id=%d&text=%s",user_id,*message);

  CURL *curl;

  //CURLcode res;

  //static const char *postthis = "moo mooo moo moo";

  curl_global_init(CURL_GLOBAL_ALL);

  curl = curl_easy_init();

  if(curl) {

    curl_easy_setopt(curl, CURLOPT_URL, url);

    curl_easy_setopt(curl, CURLOPT_POSTFIELDS,data);

    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);

    curl_easy_perform(curl);

  }

  curl_global_cleanup();

}

编译器返回：

cgo-gcc-prolog:129:19: 错误：数组大小为负数

我编写了一个 webhook 函数，但触发了 notificationWebhook 函数并发送了错误的参数。为什么？我哪里会犯错误？

Answer 1

字符串到 char (*array)[]cgo-gcc-prolog: error: array size is negative使用垫片。例如，so.go:// string to char (*array)[]package main/*#include <stdlib.h>#include <stdio.h>void notify(char (*message)[]) {&nbsp; &nbsp; printf("notify | argv: %1$p %1$s\n", *message);}void shimmy(char *message[]) {&nbsp; &nbsp; printf("shimmy | argv: %1$p %1$s\n", *message);&nbsp; &nbsp; notify((char (*)[])*message);}*/import "C"import (&nbsp; &nbsp; "fmt"&nbsp; &nbsp; "unsafe")func main() {&nbsp; &nbsp; message := "My Message :)"&nbsp; &nbsp; cs := C.CString(message)&nbsp; &nbsp; defer C.free(unsafe.Pointer(cs))&nbsp; &nbsp; fmt.Printf("main&nbsp; &nbsp;| argv: %p %s\n", cs, C.GoString(cs))&nbsp; &nbsp; C.shimmy(&cs)}输出：$ go run so.gomain&nbsp; &nbsp;| argv: 0x19cb820 My Message :)shimmy | argv: 0x19cb820 My Message :)notify | argv: 0x19cb820 My Message :)$&nbsp;$ go versiongo version devel +4d5bb9c609 Fri Dec 20 23:07:52 2019 +0000 linux/amd64$ go env CCgcc$ gcc --versiongcc (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008$&nbsp;