paho mqtt client调试记录

本文介绍了Eclipse Paho C客户端的编译流程,针对编译中找不到clock_gettime函数的错误,给出在Makefile添加-lrt的解决办法。还展示了单独编译测试代码的命令,测试了订阅部分,修改原版demo建立4个连接并订阅多个主题,最后给出修改后的代码。

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官网:http://www.eclipse.org/paho/clients/c/

编译流程:

git clone https://github.com/eclipse/paho.mqtt.c.git
cd org.eclipse.paho.mqtt.c.git
make
sudo make install

 

编译过程中报找不到clock_gettime函数的错误,在Makefile中相关位置添加-lrt就可以了。

make后sample里的测试代码也会跟着成功编译。

也可以在sample目录下单独用命令编译:gcc -I../ -L../../../paho.mqtt.c/build/output/ MQTTClient_subscribe.c -lpaho-mqtt3c -o MQTTTest -lrt

 

我测试了订阅部分,修改了原版demo,同时和服务器建立4个连接,每个连接又订阅了4个主题。通过对主题进行数据发送和抓包分析,都显示没问题。

修改后的代码如下:

/*******************************************************************************
 * Copyright (c) 2012, 2017 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution. 
 *
 * The Eclipse Public License is available at 
 *   http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at 
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Ian Craggs - initial contribution
 *******************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MQTTClient.h"

//#define ADDRESS     "tcp://localhost:1883"
//#define ADDRESS     "192.168.0.167"
#define ADDRESS     "192.168.0.117"
#define CLIENTID    "ExampleClientSub"
#define TOPIC       "1234/qinrenzhi"
#define TOPIC_11    "1234/qinrenzhi_11"
#define TOPIC_12    "1234/qinrenzhi_12"
#define TOPIC_13    "1234/qinrenzhi_13"
#define TOPIC_14    "1234/qinrenzhi_14"

#define PAYLOAD     "Hello World!"
#define QOS         1
#define TIMEOUT     10000L

#define CLIENTID_2    "ExampleClientSub_2"
#define TOPIC_2       "1234/qinrenzhi_2"
#define TOPIC_21      "1234/qinrenzhi_21"
#define TOPIC_22      "1234/qinrenzhi_22"
#define TOPIC_23      "1234/qinrenzhi_23"

#define CLIENTID_3    "ExampleClientSub_3"
#define TOPIC_3       "1234/qinrenzhi_3"
#define TOPIC_31       "1234/qinrenzhi_31"
#define TOPIC_32       "1234/qinrenzhi_32"
#define TOPIC_33       "1234/qinrenzhi_33"

#define CLIENTID_4    "ExampleClientSub_4"
#define TOPIC_4       "1234/qinrenzhi_4"
#define TOPIC_41      "1234/qinrenzhi_41"
#define TOPIC_42      "1234/qinrenzhi_42"
#define TOPIC_43      "1234/qinrenzhi_43"


volatile MQTTClient_deliveryToken deliveredtoken_2;

void delivered_2(void *context, MQTTClient_deliveryToken dt)
{
    printf("2:Message with token value %d delivery confirmed\n", dt);
    deliveredtoken_2 = dt;
}

int msgarrvd_2(void *context, char *topicName, int topicLen, MQTTClient_message *message)
{
    int i;
    char* payloadptr;

    printf("2:Message arrived\n");
    printf("2:     topic: %s\n", topicName);
    printf("2:   message: ");

    payloadptr = message->payload;
    for(i=0; i<message->payloadlen; i++)
    {
        putchar(*payloadptr++);
    }
    putchar('\n');
    MQTTClient_freeMessage(&message);
    MQTTClient_free(topicName);
    return 1;
}

void connlost_2(void *context, char *cause)
{
    printf("\n2:Connection lost\n");
    printf("     cause: %s\n", cause);
}

volatile MQTTClient_deliveryToken deliveredtoken_3;

void delivered_3(void *context, MQTTClient_deliveryToken dt)
{
    printf("3:Message with token value %d delivery confirmed\n", dt);
    deliveredtoken_3 = dt;
}

int msgarrvd_3(void *context, char *topicName, int topicLen, MQTTClient_message *message)
{
    int i;
    char* payloadptr;

    printf("3:Message arrived\n");
    printf("3:     topic: %s\n", topicName);
    printf("3:   message: ");

    payloadptr = message->payload;
    for(i=0; i<message->payloadlen; i++)
    {
        putchar(*payloadptr++);
    }
    putchar('\n');
    MQTTClient_freeMessage(&message);
    MQTTClient_free(topicName);
    return 1;
}

void connlost_3(void *context, char *cause)
{
    printf("\n3:Connection lost\n");
    printf("     cause: %s\n", cause);
}


volatile MQTTClient_deliveryToken deliveredtoken_4;

void delivered_4(void *context, MQTTClient_deliveryToken dt)
{
    printf("4:Message with token value %d delivery confirmed\n", dt);
    deliveredtoken_4 = dt;
}

int msgarrvd_4(void *context, char *topicName, int topicLen, MQTTClient_message *message)
{
    int i;
    char* payloadptr;

    printf("4:Message arrived\n");
    printf("4:     topic: %s\n", topicName);
    printf("4:   message: ");

    payloadptr = message->payload;
    for(i=0; i<message->payloadlen; i++)
    {
        putchar(*payloadptr++);
    }
    putchar('\n');
    MQTTClient_freeMessage(&message);
    MQTTClient_free(topicName);
    return 1;
}

void connlost_4(void *context, char *cause)
{
    printf("\n4:Connection lost\n");
    printf("     cause: %s\n", cause);
}


volatile MQTTClient_deliveryToken deliveredtoken;

void delivered(void *context, MQTTClient_deliveryToken dt)
{
    printf("Message with token value %d delivery confirmed\n", dt);
    deliveredtoken = dt;
}

int msgarrvd(void *context, char *topicName, int topicLen, MQTTClient_message *message)
{
    int i;
    char* payloadptr;

    printf("Message arrived\n");
    printf("     topic: %s\n", topicName);
    printf("   message: ");

    payloadptr = message->payload;
    for(i=0; i<message->payloadlen; i++)
    {
        putchar(*payloadptr++);
    }
    putchar('\n');
    MQTTClient_freeMessage(&message);
    MQTTClient_free(topicName);
    return 1;
}

void connlost(void *context, char *cause)
{
    printf("\nConnection lost\n");
    printf("     cause: %s\n", cause);
}

int main(int argc, char* argv[])
{
    MQTTClient client;
    MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
    int rc;
    int ch;

    MQTTClient_create(&client, ADDRESS, CLIENTID,
        MQTTCLIENT_PERSISTENCE_NONE, NULL);
    conn_opts.keepAliveInterval = 200;
    conn_opts.cleansession = 1;

    MQTTClient_setCallbacks(client, NULL, connlost, msgarrvd, delivered);

    if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
    {
        printf("Failed to connect, return code %d\n", rc);
        exit(EXIT_FAILURE);
    }
    printf("Subscribing to topic %s\nfor client %s using QoS%d\n\n"
           "Press Q<Enter> to quit\n\n", TOPIC, CLIENTID, QOS);
    MQTTClient_subscribe(client, TOPIC, QOS);
    MQTTClient_subscribe(client, TOPIC_11, QOS);
    MQTTClient_subscribe(client, TOPIC_12, QOS);
    MQTTClient_subscribe(client, TOPIC_13, QOS);

    MQTTClient client_2;
    MQTTClient_connectOptions conn_opts_2 = MQTTClient_connectOptions_initializer;
    int rc_2;
    int ch_2;

    MQTTClient_create(&client_2, ADDRESS, CLIENTID_2,
        MQTTCLIENT_PERSISTENCE_NONE, NULL);
    conn_opts_2.keepAliveInterval = 200;
    conn_opts_2.cleansession = 1;

    MQTTClient_setCallbacks(client_2, NULL, connlost_2, msgarrvd_2, delivered_2);

    if ((rc_2 = MQTTClient_connect(client_2, &conn_opts_2)) != MQTTCLIENT_SUCCESS)
    {
        printf("2:Failed to connect, return code %d\n", rc);
        exit(EXIT_FAILURE);
    }
    printf("2:Subscribing to topic %s\nfor client %s using QoS%d\n\n"
           "Press Q<Enter> to quit\n\n", TOPIC_2, CLIENTID_2, QOS);
    MQTTClient_subscribe(client_2, TOPIC_2, QOS);
    MQTTClient_subscribe(client_2, TOPIC_21, QOS);
    MQTTClient_subscribe(client_2, TOPIC_22, QOS);
    MQTTClient_subscribe(client_2, TOPIC_23, QOS);


    MQTTClient client_3;
    MQTTClient_connectOptions conn_opts_3 = MQTTClient_connectOptions_initializer;
    int rc_3;
    int ch_3;

    MQTTClient_create(&client_3, ADDRESS, CLIENTID_3,
        MQTTCLIENT_PERSISTENCE_NONE, NULL);
    conn_opts_3.keepAliveInterval = 200;
    conn_opts_3.cleansession = 1;

    MQTTClient_setCallbacks(client_3, NULL, connlost_3, msgarrvd_3, delivered_3);

    if ((rc_3 = MQTTClient_connect(client_3, &conn_opts_3)) != MQTTCLIENT_SUCCESS)
    {
        printf("3:Failed to connect, return code %d\n", rc);
        exit(EXIT_FAILURE);
    }
    printf("3:Subscribing to topic %s\nfor client %s using QoS%d\n\n"
           "Press Q<Enter> to quit\n\n", TOPIC_3, CLIENTID_3, QOS);
    MQTTClient_subscribe(client_3, TOPIC_3, QOS);
    MQTTClient_subscribe(client_3, TOPIC_31, QOS);
    MQTTClient_subscribe(client_3, TOPIC_32, QOS);
    MQTTClient_subscribe(client_3, TOPIC_33, QOS);


    MQTTClient client_4;
    MQTTClient_connectOptions conn_opts_4 = MQTTClient_connectOptions_initializer;
    int rc_4;
    int ch_4;

    MQTTClient_create(&client_4, ADDRESS, CLIENTID_4,
        MQTTCLIENT_PERSISTENCE_NONE, NULL);
    conn_opts_4.keepAliveInterval = 200;
    conn_opts_4.cleansession = 1;

    MQTTClient_setCallbacks(client_4, NULL, connlost_4, msgarrvd_4, delivered_4);

    if ((rc_4 = MQTTClient_connect(client_4, &conn_opts_4)) != MQTTCLIENT_SUCCESS)
    {
        printf("4:Failed to connect, return code %d\n", rc);
        exit(EXIT_FAILURE);
    }
    printf("4:Subscribing to topic %s\nfor client %s using QoS%d\n\n"
           "Press Q<Enter> to quit\n\n", TOPIC_4, CLIENTID_4, QOS);
    MQTTClient_subscribe(client_4, TOPIC_4, QOS);
    MQTTClient_subscribe(client_4, TOPIC_41, QOS);
    MQTTClient_subscribe(client_4, TOPIC_42, QOS);
    MQTTClient_subscribe(client_4, TOPIC_43, QOS);

    do 
    {
        ch = getchar();
    } while(ch!='Q' && ch != 'q');

    MQTTClient_unsubscribe(client, TOPIC);
    MQTTClient_unsubscribe(client, TOPIC_11);
    MQTTClient_unsubscribe(client, TOPIC_12);
    MQTTClient_unsubscribe(client, TOPIC_13);
    MQTTClient_disconnect(client, 10000);
    MQTTClient_destroy(&client);


    MQTTClient_unsubscribe(client_2, TOPIC);
    MQTTClient_unsubscribe(client_2, TOPIC_21);
    MQTTClient_unsubscribe(client_2, TOPIC_22);
    MQTTClient_unsubscribe(client_2, TOPIC_23);
    MQTTClient_disconnect(client_2, 10000);
    MQTTClient_destroy(&client_2);

    MQTTClient_unsubscribe(client_3, TOPIC);
    MQTTClient_unsubscribe(client_3, TOPIC_31);
    MQTTClient_unsubscribe(client_3, TOPIC_32);
    MQTTClient_unsubscribe(client_3, TOPIC_33);  
    MQTTClient_disconnect(client_3, 10000);
    MQTTClient_destroy(&client_3);

    MQTTClient_unsubscribe(client_4, TOPIC);
    MQTTClient_unsubscribe(client_4, TOPIC_41);
    MQTTClient_unsubscribe(client_4, TOPIC_42);
    MQTTClient_unsubscribe(client_4, TOPIC_43);
    MQTTClient_disconnect(client_4, 10000);
    MQTTClient_destroy(&client_4);


    return rc;
}
 

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