How to go from a JS string[] to a C array of pointers

Hi,
Trying to call a C function with FFI but struggling to covert a string[] to an array of pointers. Lets asume the following C function

void test_multi(int argc, const char * const *argv) {
  for (int i = 0; i < argc; i++) {
    puts(argv[i]);
  }
}

void test_multi(int argc, const char * const *argv) {
  for (int i = 0; i < argc; i++) {
    puts(argv[i]);
  }
}

And using some JS code I can try to call it

const enc = new TextEncoder()
const test = Deno.dlopen('./test.so'), {
   test_multi: {
      parameters: ['i32', 'buffer'],
      result: 'void'
   }
})

const params = [ 'ASD', 'ZXC' ]
test.symbols.test_multi(params.length, ??????)

const enc = new TextEncoder()
const test = Deno.dlopen('./test.so'), {
   test_multi: {
      parameters: ['i32', 'buffer'],
      result: 'void'
   }
})

const params = [ 'ASD', 'ZXC' ]
test.symbols.test_multi(params.length, ??????)

Is bufferbuffer the right type for that parameter I better us pointerpointer?. And finally how to convert the paramsparams array to something that can be sent to the C function.

Appreciate the help.

Deno•2y ago•

20 replies

carragom

How to go from a JS string[] to a C array of pointers

Hi,
Trying to call a C function with FFI but struggling to covert a string[] to an array of pointers. Lets asume the following C function

void test_multi(int argc, const char * const *argv) {
  for (int i = 0; i < argc; i++) {
    puts(argv[i]);
  }
}

void test_multi(int argc, const char * const *argv) {
  for (int i = 0; i < argc; i++) {
    puts(argv[i]);
  }
}

And using some JS code I can try to call it

const enc = new TextEncoder()
const test = Deno.dlopen('./test.so'), {
   test_multi: {
      parameters: ['i32', 'buffer'],
      result: 'void'
   }
})

const params = [ 'ASD', 'ZXC' ]
test.symbols.test_multi(params.length, ??????)

const enc = new TextEncoder()
const test = Deno.dlopen('./test.so'), {
   test_multi: {
      parameters: ['i32', 'buffer'],
      result: 'void'
   }
})

const params = [ 'ASD', 'ZXC' ]
test.symbols.test_multi(params.length, ??????)

Continue the conversation

Join the Discord to ask follow-up questions and connect with the community

Deno

Chat about Deno, a modern runtime for JavaScript and TypeScript.

20,934 Members

Join

How to go from a JS string[] to a C array of pointers

How to go from a JS string[] to a C array of pointers

Continue the conversation

Deno

Continue the conversation

Deno

Similar Threads