到这里就可以将前一博客中构建的框架放入项目代码中了，只需要修改之前项目中相关socket代码部分即可。
1.发布端：#include2.订阅端：#include #include #include #include #include #include #include #include #include #include #include #include #include "mosquitto.h" #include #include "ds18b20.h" #include #include #define BUF_SZIE 1024 #define ARRY_SIZE(x) (sizeof(x)/sizeof(x[0])) #define KEEP_ALIVE 60 int g_stop = 0; static inline void print_usage(char *progname); void sig_handler(int sig_num) { if(sig_num == SIGUSR1) g_stop = 1; } int main (int argc, char **argv) { char *progname = basename(argv[0]); int port; char *ip = NULL; char *hostname = NULL; char *topic = NULL; struct hostent *hostentp; struct mosquitto *mosq = NULL; int daemon_run = 0; int opt; int rv; float temperature = 0; char buffer[BUF_SZIE]; time_t t; struct tm *timep; int log_fd; int connect_flag = 1; struct option options[] = { {"daemon",no_argument,NULL,'d'}, {"topic", required_argument,NULL,'t'}, {"hostname", required_argument,NULL,'n'}, {"ip", required_argument, NULL, 'i'}, {"port",required_argument,NULL,'p'}, {"help",no_argument,NULL,'h'}, {NULL,0,NULL,0} }; while((opt = getopt_long(argc,argv,"dhp:t:i:n:",options,NULL)) != -1) { switch(opt) { case 't': topic = optarg; break; case 'i': ip = optarg; break; case 'n': hostname = optarg; break; case 'd': daemon_run = 1; break; case 'p': port = atoi(optarg); break; case 'h': print_usage(argv[0]); return 0; default: break; } } if(!port) { print_usage(progname); return -1; } if(!hostname && !ip) { print_usage(progname); return -1; } if(hostname) { hostentp = gethostbyname(hostname); if(!hostentp) { printf("Failed to get host by name: %sn",strerror(errno)); return -2; } printf("hostname: %sn",hostentp->h_name); ip = inet_ntoa(*(struct in_addr *)hostentp->h_addr); printf("address: %sn",ip); } if(!topic) { topic = "temperature"; } if(daemon_run) { printf("program %s running in backgrundn", progname); if( (log_fd = open("client.log", O_CREAT|O_RDWR, 0666)) < 0) { printf("open() failed:%sn", strerror(errno)) ; return -2; } dup2(log_fd, STDOUT_FILENO) ; dup2(log_fd, STDERR_FILENO) ; daemon(1,1); } signal(SIGUSR1,sig_handler); mosquitto_lib_init(); mosq = mosquitto_new(NULL,true,NULL); if(!mosq) { printf("mosquitto_new() failed: %sn",strerror(errno)); mosquitto_lib_cleanup(); return -1; } printf("Create mosquitto successfully!n"); if(mosquitto_connect(mosq,ip,port,KEEP_ALIVE) != MOSQ_ERR_SUCCESS) { printf("mosquitto_connect() failed: %sn",strerror(errno)); mosquitto_destroy(mosq); mosquitto_lib_cleanup(); return -1; } printf("connect %s:%d successfully!n",ip,port); if(mosquitto_loop_start(mosq) != MOSQ_ERR_SUCCESS) { printf("mosquitto_loop_start() failed: %sn",strerror(errno)); mosquitto_destroy(mosq); mosquitto_lib_cleanup(); } while(!g_stop) { if(ds18b20_get_temperature(&temperature) < 0) { printf("ds18b20_get_temperature failed.n"); return -3; } time(&t); char * str = ctime(&t);//此字符串后有回车换行及‘/n’,所以要去掉 char tempbuff[25]; memset(tempbuff,0,25); memcpy(tempbuff,str,24); snprintf(buffer,ARRY_SIZE(buffer),"%s%f",tempbuff,temperature); printf("%sn",buffer); if(mosquitto_publish(mosq,NULL,topic,strlen(buffer),buffer,0,0) != MOSQ_ERR_SUCCESS) { printf("mosquitto_publish() failed: %sn",strerror(errno)); mosquitto_destroy(mosq); mosquitto_lib_cleanup(); }else { printf("Publish information of temperature Ok!n") ; } sleep(30); } close(log_fd); return 0; } void print_usage(char *progname) { printf("%s usage:n",progname); printf("-p(--port): sepcify server listen port.n"); printf("-h(--Help): print this help information.n"); printf("-d(--daemon): set program running on background.n"); printf("nExample: %s -d -p 8889n",progname); }
#include#include #include #include #include #include #include #include #include #include #include #include #include #include "mosquitto.h" #include #include #include #define MSG_MAX_SZIE 1024 #define ARRY_SIZE(x) (sizeof(x)/sizeof(x[0])) #define KEEP_ALIVE 60 static inline void print_usage(char *progname); int dboperate(char *buffer); int g_stop = 0; void my_message_calllback(struct mosquitto *mosq,void *obj,const struct mosquitto_message *msg); void sig_handler(int sig_num) { if(sig_num == SIGUSR1) g_stop = 1; } int main (int argc, char **argv) { char *progname = basename(argv[0]); char *ip = NULL; char *hostname = NULL; char *topic = NULL; struct hostent *hostentp; struct mosquitto *mosq = NULL; int connect_flag = 1; int log_fd; int port; int daemon_run = 0; int opt; char buffer[MSG_MAX_SZIE]; //char *obj = buffer; struct option options[] = { {"daemon",no_argument,NULL,'d'}, {"port",required_argument,NULL,'p'}, {"topic", required_argument,NULL,'t'}, {"hostname", required_argument,NULL,'n'}, {"ip", required_argument, NULL, 'i'}, {"help",no_argument,NULL,'h'}, {NULL,0,NULL,0} }; while((opt = getopt_long(argc,argv,"dhp:t:i:n:",options,NULL)) != -1) { switch(opt) { case 't': topic = optarg; break; case 'i': ip = optarg; break; case 'n': hostname = optarg; break; case 'd': daemon_run = 1; break; case 'p': port = atoi(optarg); break; case 'h': print_usage(argv[0]); return 0; default: break; } } if(!port) { print_usage(progname); return -1; } if(!hostname && !ip) { print_usage(progname); return -1; } if(hostname) { hostentp = gethostbyname(hostname); if(!hostname) { printf("Failed to get host by name: %sn",strerror(errno)); return -2; } printf("hostname: %sn",hostentp->h_name); ip = inet_ntoa(*(struct in_addr *)hostentp->h_addr); printf("address: %sn",ip); } if(!topic) { topic = "temperature"; } if(daemon_run) { printf("program %s running in backgroundn",progname); if((log_fd = open("server.log",O_CREAT|O_RDWR,0666)) < 0) { printf("open() server.log failed: %sn",strerror(errno)); return -2; } dup2(log_fd,STDOUT_FILENO); dup2(log_fd,STDERR_FILENO); daemon(1,1); } signal(SIGUSR1,sig_handler); mosquitto_lib_init(); mosq = mosquitto_new(NULL,true,(void *)buffer);//obj 用户指针的使用在这里 if(!mosq) { printf("failed to new mosquitto: %sn",strerror(errno)); mosquitto_lib_cleanup(); return -1; } printf("new mosq successfully!n"); mosquitto_message_callback_set(mosq,my_message_calllback); if(mosquitto_connect(mosq,ip,port,KEEP_ALIVE) != MOSQ_ERR_SUCCESS) { printf("mosquitto_connect() failed: %sn",strerror(errno)); mosquitto_destroy(mosq); mosquitto_lib_cleanup(); return -2; } printf("mosq connect successfully!n"); if((mosquitto_subscribe(mosq,NULL,topic,2)) != MOSQ_ERR_SUCCESS) { printf("failed to subscribe from broker: %sn",strerror(errno)); mosquitto_destroy(mosq); mosquitto_lib_cleanup(); return -3; } printf("mosq subscribe successfully!n"); while(!g_stop) { mosquitto_loop(mosq,-1,1); } mosquitto_destroy(mosq); mosquitto_lib_cleanup(); return 0; } void print_usage(char *progname) { printf("%s usage:n",progname); printf("-p(--port): sepcify server listen port.n"); printf("-h(--Help): print this help information.n"); printf("-d(--daemon): set program running on background.n"); printf("nExample: %s -d -p 8889n",progname); } int dboperate(char *buffer) { MYSQL mysql,*sock; MYSQL_RES *res; MYSQL_FIELD *fd; MYSQL_ROW row; char qbuf[1024]; char str1[25];//字符数组存字符串时 要多一个字节 来存放‘/0’ memset(str1,0,25); memcpy(str1,buffer,24); char str2[1024]; memset(str2,0,1024); memcpy(str2,buffer+24,1024-24); //printf("%dn",222); printf("%sn",str1); //printf("%dn",224); printf("%sn",str2); float t = atof(str2); mysql_init(&mysql); sock = mysql_real_connect(&mysql,"localhost","root","12345678","mydb",0,NULL,0); if(!sock) { fprintf(stderr,"Couldn't connect to database!: %sn",mysql_error(&mysql)); exit(1); } memset(qbuf,0,ARRY_SIZE(qbuf)); sprintf(qbuf,"insert temperature(subtime,temperature) values('%s',%f)",str1,t); if(mysql_query(sock,qbuf))// when mysql_query() excute seccessfully it return 0; { fprintf(stderr,"Excute failed!: %sn",mysql_error(sock)); exit(1); } printf("write into database successfully!n"); return 0; } void my_message_calllback(struct mosquitto *mosq,void *obj,const struct mosquitto_message *msg) { memset((char *)obj,0,MSG_MAX_SZIE); memcpy((char *)obj,(char *)msg->payload,MSG_MAX_SZIE); printf("%sn",(char *)obj); dboperate((char *)obj); }
再添加之前编写的从树莓派ds18b20传感器获取温度的代码即可，在这里我们采用一个单独的ds18b20.h进行调用。在写外部函数的时候，应该在源文件中写具体定义，而在对应的头文件中写声明，最后在执行文件中包含这个头文件就行了。这样的方法不仅达到了代码功能模块化的效果，也利于排查bug。
#ifndef _DS18_H_ #define _DS18_H_ #include#include #include #include #include #include #include #include #include #define PATH "/sys/bus/w1/devices/" #define BUF_SIZE 1024 extern int ds18b20_get_temperature(float *t); #endif
#include "ds18b20.h"
int ds18b20_get_temperature(float *t)
{
DIR *dirp;
struct dirent *direntp;
char path[1024];
int fd;
int rv;
char buffer[BUF_SIZE];
char *result;
if((dirp = opendir(PATH)) == NULL)
{
printf("Failed to open the destination directory: %sn",strerror(errno));
return -1;
}
while((direntp = readdir(dirp)) != NULL)
{
if(strstr(direntp->d_name,"28-") != NULL)
{
break;
}
}
if(direntp == NULL)
{
printf("Failed to find the destination directory: 28-*** .n");
closedir(dirp);
return -2;
}
memset(path,0,sizeof(path));
strcat(path,PATH);
strcat(path,direntp->d_name);
strcat(path,"/w1_slave");
closedir(dirp);
if((fd = open(path,O_RDONLY)) < 0)
{
printf("Failed to open the destination file.n");
return -3;
}
memset(buffer,0,sizeof(buffer));
while((rv = read(fd,buffer,sizeof(buffer))) > 0)
{
if((result = strstr(buffer,"t=")) != NULL)
{
result = result + 2;
break;
}
}
if(rv <= 0)
{
printf("Failed to read the temperature.n");
close(fd);
return -4;
}
*t = atof(result)/1000;
close(fd);
return 0;
}
#if 0
int main()
{
float t;
ds18b20_get_temperature(&t);
printf("%fn",t);
}
#endif
makefile：
all: @echo "" @echo "Start compiling..." @echo "" gcc -o mqttpub mqttpub.c ds18b20.c -lmosquitto gcc -o mqttsub mqttsub.c -I/usr/include/mysql -L/usr/lib/mysql -lmosquitto -lmysqlclient @echo "end" clean: rm mqttpub mqttsub runsub: ./mqttsub -p 1883 -n lastbreath.club runpub: ./mqttpub -p 1883 -n lastbreath.club
运行截图：
查看数据库：
