How to implement a function with char array on Arduino

Question

I am doing a sketch using an ESP8266 as a WiFi server, I need to send a character string to the Client, for this I am using this piece of code:

  char sbuf[] = "Hello world!\n\r";
  size_t len = strlen(sbuf);
  for (i = 0; i < MAXCLIENTS; i++) {
  if (serverClients[i] && serverClients[i].connected()) {
     serverClients[i].write((char*) &sbuf, len);
     delay(1);
   }
 }

It works OK, the client can receive the characters.

But now I want to make a function to call it the times I need it, this is the function code:

void sendDataToClient( char *sbuf[]) {
size_t len = strlen(sbuf);
for (i = 0; i < MAXCLIENTS; i++) {
if (serverClients[i] && serverClients[i].connected()) {
  serverClients[i].write((char*) &sbuf, len);
  delay(1);
  }
 }
}

That's I'm calling the function:

char bufferMSGtoClient[] = "Hello world!\n\r";

sendDataToClient(bufferMSGtoClient)

But it doesn't work, the client does not receive anything, someone can tell me what is my error?

Delta_G · Accepted Answer · 2020-05-16 06:24:48Z

4

sizeof doesn’t do what you think it does here. You’re getting 4 because that’s the size of a pointer. Use strlen instead. It will tell you how long up to the \n. Add two if you want the \r too.

void sendDataToClient( char *sbuf[]) {

This line is also not doing what you think. It is passing an array of pointers. You either want a pointer OR an array, but certainly not an array of pointers.

void sendDataToClient( char *sbuf) {

and

serverClients[i].write((char*) &sbuf, len);

should be

serverClients[i].write(sbuf, len);

I'm betting.

edited May 16, 2020 at 6:24

answered May 16, 2020 at 2:42

Delta_G

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2 Comments

DarioG Over a year ago

Delta, I have made the change, I still get the value of len 4 and the client does not receive anything

Delta_G Over a year ago

You're also passing in an array of pointers. Lose the brackets on the argument sbuf.

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