ESP8266 crashes when trying to copy a string into a big char I'm trying to parse with tinyxml2 a modest XML (3.4kb) to retrieve some data.

My ESP8266 crashes every time I try to use the toCharArray method.

here's my code

// here I'm getting an http request
String payload = https.getString();

// checking the payload, it seems fine in console but I get some garbage characters when àèéùìò are printed
Serial.println(payload);

// Length (with one extra character for the null terminator)
int str_len = payload.length() + 1;

// Prepare the character array
char xml[str_len];

// Copy it over
payload.toCharArray(xml, str_len);

// there I'll parse xml with tinyxml2 but the MCU crashes before getting here


the length of the string is something around 3900, which I'm not sure can fit this kind of array on this device. If it's the case, what will be a better strategy ?

As you can imagine I'm just starting with the c language :)

EDIT: https.getString().c_str() + less variables was the right way to save memory
Function local variable are created on the stack, and in the case of an ESP8266, the total size is limited to 4096 Bytes - so, 3900 for one variable is cutting it close.

I would recommend you either use malloc/free 

int str_len = payload.length() + 1;

// Prepare the character array
char *xml = (char *) malloc(str_len);

// Copy it over
payload.toCharArray(xml, str_len);

// there I'll parse xml with tinyxml2 but the MCU crashes before getting here
//
// when done, free the memory malloc'd

free(xml);


or, if you know an absolute maximum size for the string, e.g. 5000, make char xml[5001]; in the global scope