Files
HumidityPi/RaspberryPi/restcurl.c

103 lines
2.6 KiB
C

#include "restcurl.h"
#include <curl/curl.h>
#include <string.h>
#include <stdlib.h>
#include "cJSON.h"
struct url_data {
size_t size;
char* data;
};
static size_t write_data(void *ptr, size_t size, size_t nmemb, struct url_data *data) {
size_t index = data->size;
size_t n = (size * nmemb);
char* tmp;
data->size += (size * nmemb);
tmp = realloc(data->data, data->size + 1); /* +1 for '\0' */
if(tmp) {
data->data = tmp;
} else {
if(data->data) {
free(data->data);
}
fprintf(stderr, "Failed to allocate memory.\n");
return 0;
}
memcpy((data->data + index), ptr, n);
data->data[data->size] = '\0';
return size * nmemb;
}
static char *handle_url(char *url) {
CURL *curl;
struct url_data data;
data.size = 0;
data.data = malloc(4096); /* reasonable size initial buffer */
if(NULL == data.data) {
fprintf(stderr, "Failed to allocate memory.\n");
return NULL;
}
data.data[0] = '\0';
CURLcode res;
curl = curl_easy_init();
if (curl) {
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &data);
res = curl_easy_perform(curl);
if(res != CURLE_OK) {
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(res));
}
curl_easy_cleanup(curl);
}
return data.data;
}
int getRestSensor(sensor *sensor) {
char url[25];
strcpy(url, "http://");
strcat(url, sensor->ip);
char *data = handle_url(url);
if (data) {
cJSON *jsondata = cJSON_Parse(data);
cJSON *variables = cJSON_GetObjectItemCaseSensitive(jsondata, "variables");
//These two are in the catergory variables
cJSON *temperature = cJSON_GetObjectItemCaseSensitive(variables, "temperature");
cJSON *humidity = cJSON_GetObjectItemCaseSensitive(variables, "humidity");
//The ID is stored in the JSON root
cJSON *id = cJSON_GetObjectItemCaseSensitive(jsondata, "id");
if (temperature != NULL && humidity != NULL && id != NULL) {
sensor->temperature = (float)temperature->valuedouble;
sensor->humidity = (float)humidity->valuedouble;
sensor->node_id = atoi(id->valuestring);
} else {
//free
cJSON_Delete(jsondata);
free(data);
return 0;
}
//free
cJSON_Delete(jsondata);
free(data);
return 1;
}
return 0;
}