linux平台用c/c++如何连接亚马逊平台的aws iot core，与设备进行交互，具体代码实现

连接 AWS IoT Core 平台需要使用 AWS IoT Device SDK for C，以下是一个简单的示例代码，用于连接 AWS IoT Core 平台，并发布一条消息：

#include <aws/iot/mqtt_client_interface.h>
#include <aws/iot/secure_tunneling.h>
#include <aws/iot/credential_provider.h>
#include <aws/iot/shadow/shadow_client.h>
#include <aws/iot/shadow/manager.h>
#include <aws/iot/shadow/thing_name_for_topic.h>
#include <mqtt_client_sample.h>
#include <iostream>
#include <cstring>
#include <csignal>

static void s_print_client_id(const char *prefix, const char *p_client_id) {
    AWS_LOGSTREAM_INFO(MQTT_SAMPLE_LOG_TAG, prefix << " client id: " << p_client_id);
}

static void s_on_connection_complete(struct aws_mqtt_client_connection *p_connection, int error_code) {
    if (AWS_OP_SUCCESS == error_code) {
        AWS_LOGSTREAM_INFO(MQTT_SAMPLE_LOG_TAG, "connection succeeded!");
    } else {
        AWS_LOGSTREAM_WARN(MQTT_SAMPLE_LOG_TAG, "connection failed with error code " << error_code);
    }
}

static void s_on_publish_complete(struct aws_mqtt_client_connection *p_connection, uint16_t packet_id, int error_code) {
    if (AWS_OP_SUCCESS == error_code) {
        AWS_LOGSTREAM_INFO(MQTT_SAMPLE_LOG_TAG, "publish succeeded! packet id=" << packet_id);
    } else {
        AWS_LOGSTREAM_WARN(MQTT_SAMPLE_LOG_TAG, "publish failed with error code " << error_code);
    }
}

int main(int argc, char **argv) {
    struct aws_allocator *p_allocator = aws_default_allocator();
    struct aws_mqtt_client *p_client = NULL;
    struct aws_mqtt_connection_options conn_options = AWS_MQTT_CONNECTION_OPTIONS_INIT;
    struct aws_byte_cursor client_id_cursor = aws_byte_cursor_from_c_str("my_client_id");
    struct aws_byte_cursor will_topic_cursor = aws_byte_cursor_from_c_str("my_will_topic");
    struct aws_byte_cursor will_payload_cursor = aws_byte_cursor_from_c_str("my_will_payload");
    struct aws_byte_cursor username_cursor = aws_byte_cursor_from_c_str("my_username");
    struct aws_byte_cursor password_cursor = aws_byte_cursor_from_c_str("my_password");
    struct aws_mqtt_message publish_message;
    struct aws_byte_cursor topic_cursor = aws_byte_cursor_from_c_str("my_topic");
    struct aws_byte_cursor payload_cursor = aws_byte_cursor_from_c_str("my_message");

    // Initialize the SDK
    aws_load_error_strings();
    aws_io_load_error_strings();
    aws_http_load_error_strings();
    aws_auth_load_error_strings();
    aws_mqtt_load_error_strings();

    // Create a client
    p_client = aws_mqtt_client_new(p_allocator, &aws_default_client_bootstrap);
    if (NULL == p_client) {
        std::cerr << "Failed to create MQTT client" << std::endl;
        return AWS_OP_ERR;
    }

    // Set up the connection options
    conn_options = aws_mqtt_connection_options_clean_session_init(&client_id_cursor);
    conn_options.will = aws_byte_cursor_from_buf(&will_payload_cursor);
    conn_options.will_topic = aws_byte_cursor_from_buf(&will_topic_cursor);
    conn_options.username = aws_byte_cursor_from_buf(&username_cursor);
    conn_options.password = aws_byte_cursor_from_buf(&password_cursor);
    conn_options.keep_alive_time_secs = 60;

    // Set up the publish message
    publish_message = aws_mqtt_message_publish_init(&topic_cursor, AWS_MQTT_QOS_AT_LEAST_ONCE, &payload_cursor);
    publish_message.on_complete = s_on_publish_complete;

    // Connect to the broker
    aws_mqtt_client_connection_connect(p_client, &conn_options, NULL /* p_tls_options */, s_on_connection_complete, NULL /* p_user_data */);

    // Wait for the connection to complete before publishing a message
    // Real-world code should use a condition variable or other synchronization mechanism instead of a sleep loop
    while (AWS_MQTT_CLIENT_STATE_CONNECTED != aws_mqtt_client_connection_get_state(p_client)) {
        aws_thread_current_sleep(1000);
    }

    // Publish a message
    aws_mqtt_client_connection_publish(p_client, &publish_message);

    // Clean up
    aws_mqtt_client_connection_disconnect(p_client);
    aws_mqtt_client_release(p_client);
    aws_mqtt_library_clean_up();
    aws_http_library_clean_up();
    aws_io_library_clean_up();
    aws_auth_library_clean_up();
    aws_secure_tunneling_library_clean_up();
    aws_crt_cleanup();
    return AWS_OP_SUCCESS;
}

需要注意的是，此示例代码仅用于演示连接 AWS IoT Core 平台和发布一条消息，实际应用中还需要考虑更多的细节和安全性问题。