我正在尝试使用字符串数组作为参数从 C/C++ 调用 JS 函数。
这是我的示例代码:
main.c:
#include <stdio.h>
#include <emscripten.h>
EM_JS(void, call_myFunc, (int argc, char **argv), {
var arr = [];
for (let i = 0; i < argc; i++) {
arr.push(UTF8ToString(argv[i]));
}
myFunc(arr);
});
int main()
{
int argc = 4;
char *argv[5] = { "ab", "cd", "ef", "gh" };
call_myFunc(argc, argv);
}
index.html:
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script>
function myFunc(args) {
console.log(args);
}
</script>
<script async src="main.js"></script>
</body>
</html>
构建:
emcc main.c -o main.html
我得到的结果:
["", "", "", ""]
我想要的结果:
["ab", "cd", "ef", "gh"]
如何正确地将 char **argv 转换为 JS 字符串数组？
最佳答案
How can I properly convert
char **argvto a JS array of strings?
来自 emscripten.h 的文档:
Null-terminated C strings can also be passed into
EM_JSfunctions, but to operate on them, they need to be copied out from the heap to convert to high-level JavaScript strings.
EM_JS(void, say_hello, (const char* str), {
console.log('hello ' + UTF8ToString(str));
}
In the same manner, pointers to any type (including
void *) can be passed insideEM_JScode, where they appear as integers likechar *pointers above did. Accessing the data can be managed by reading the heap directly.
EM_JS(void, read_data, (int* data), {
console.log('Data: ' + HEAP32[data>>2] + ', ' + HEAP32[(data+4)>>2]);
});
int main() {
int arr[2] = { 30, 45 };
read_data(arr);
return 0;
}
因此，您可以将 HEAP32 与 UTF8ToString 一起使用，如下所示:
main.c
#include <stdio.h>
#include <emscripten.h>
EM_JS(void, call_myFunc, (const int argc, const char** argv), {
var arr = [];
for (let i = 0; i < argc; i++) {
const mem = HEAP32[(argv + (i * 4)) >> 2];
const str = UTF8ToString(mem);
arr.push(str);
}
console.log(arr);
});
int main() {
const int argc = 4;
const char* argv[] = { "ab", "cd", "ef", "gh" };
call_myFunc(argc, argv);
return 0;
}
编译:
emcc main.c -o main.html
使用节点运行:
node main.js
输出:
[ 'ab', 'cd', 'ef', 'gh' ]
关于javascript - EM_JS : How to convert int argc, char **argv 到 JS 字符串数组？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/63321398/