文章目录
- 一、项目介绍
- 二、软件架构
- 客户端
- 服务器端
- 三、代码
- 服务器端代码
- 四、安装说明
- 五、使用说明
- 六、本项目gitee仓库
一、项目介绍
该项目由客户端和服务器两端程序组成,以树莓派为客户端,远程服务器为服务器端,利用socket通信,将树莓派上采集的ds18b20的温度传感数据发送到服务器端。如果断开连接,客户端将采集的数据存于sqlite3数据库中,同样服务器端也会把每次接收到的数据存于sqlite3数据库中。
二、软件架构
客户端
1.树莓派上运行socket客户端程序, 每隔30秒以字符串“设备号/日期时间/温度”形式上报采样温度,设备号便于服务器端区分是哪个树莓派客户端,如“RPI200/2022.4.4-12:01/28.00”;
2.通过命令行参数指定服务器端IP地址和端口以及间隔采样时间;
3.程序放到后台运行,并通过syslog记录程序的运行出错、调试日志;
4.程序可以捕捉kill信号正常退出;
5.当服务器断开时,将采集的数据存放至本地数据库中,等再次连接上服务器时,将已保存在数据库中的数据重新发送给服务器。
客户端程序流程图如下:
服务器端
1.服务器程序运行啊在Linux服务器上;
2.通过命令行指定监听的端口;
3.程序能够捕捉kill信号正常退出;
4.服务器支持多个客户端并发访问,选择epoll实现多路复用;
5.服务器收到每个客户端的数据都解析后保存到数据库中,接收到的格式为:“设备号/日期时间/温度”,如“RPI200/2022.4.4-12:01/28.00”;
服务器端程序流程图如下:
三、代码
客户端代码:
/*********************************************************************************
* Copyright: (C) 2022 Zhang Changxing<ZhangChangxingVIP@163.com>
* All rights reserved.
*
* Filename: client.c
* Description: This file Collect the temperature data on the ds18b20 sensor and send it to the server. If the sending fails, it will be stored in the database temperature.db.
*
* Version: 1.0.0(04/04/2022)
* Author: Zhang Changxing <ZhangChangxingVIP@163.com>
* ChangeLog: 1, Release initial version on "04/04/2022 05:44:50 AM"
*
********************************************************************************/
#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <string.h>
#include <getopt.h>
#include <time.h>
#include <sqlite3.h>
#include <signal.h>
#include <syslog.h>
#include <libgen.h>
#include <linux/tcp.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#define TABLE_NAME "RPI1"
struct timeval tv;
struct tm* st;
char datime[100];
static double current_time = 0;
static double last_time = 0;
char *buftok[3];
struct sockaddr_in servaddr;
int sockfd = -1;
int port =0;
char *ip_addr = NULL;
int connfd = -1;
static int count = 0;
int rc = -1;
sqlite3 *db;
char *zErrMsg = 0;
int iTableExist = 0;
char write_buffer2[100];
int g_sigstop = 0;
struct tcp_info info;
int temperature (float *temp);
static inline void print_usage(char *programe);
void sqlite_init(void);
static int callback(void *NotUsed, int argc, char **argv, char **azColName);
void sqlite_create_table(char *table_name);
void sqlite_inset(char *buftok[], char *table_name);
int sqlite_delete(int id, char *table_name);
double getime(char *datime);
int client_socket_init(void);
int sendata(int sockfd, char *buftok[]);
int sqlite_table_exist(char *table_name);
static int table_exist_callback(void *data, int argc, char **argv, char **azColName);
int table_row_count(char *table_name);
static int callback_row_count(void *NotUsed, int argc, char **argv, char **azColName);
int sendata2(int sockfd, char *table_name, int count);
static int sendata2_callback(void *data, int argc, char **argv, char **azColName);
void signal_stop(int signum);
int SocketConnected(int sockfd);
int main (int argc, char **argv)
{
float temp = 0;
int rv = -1;
int ch;
int daemon_run =0;
int con_status = 1;
char count_buffer[20];
struct sigaction sigact;
struct sigaction sigign;
char *programe_name;
char temp_buffer[10];
struct option opts[] = {
{"ip_addr", required_argument, NULL, 'i'},
{"port", required_argument, NULL, 'p'},
{"daemon", no_argument, NULL, 'b'},
{"help", no_argument, NULL, 'h'},
{0, 0, 0, 0}
};
while((ch = getopt_long(argc, argv, "i:p:bh", opts, NULL)) != -1)
{
switch(ch)
{
case 'i':
{
ip_addr = optarg;
break;
}
case 'p':
{
port = atoi(optarg);
break;
}
case 'b':
{
daemon_run = 1;
break;
}
case 'h':
{
print_usage(argv[0]);
break;
}
default:
{
printf("Invalid argument\n");
return -1;
}
}
}
if(port == 0 || ip_addr == NULL)
{
printf("Invalid port or IP address is NULL!\n");
return -2;
}
if(daemon_run)
{
if(daemon(0, 0))
{
printf("Running daemon failure:%s\n", strerror(errno));
}
printf("Running daemon successfully!\n");
}
programe_name = basename(argv[0]);
openlog(programe_name, LOG_CONS|LOG_PID, 0);
sigemptyset(&sigign.sa_mask);
sigign.sa_flags = 0;
sigign.sa_handler = SIG_IGN;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0;
sigact.sa_handler = signal_stop;
//sigaction(SIGINT, &sigign, 0);
sigaction(SIGUSR1, &sigact, 0);
sigaction(SIGUSR2, &sigact, 0);
connfd = client_socket_init();
if(connfd < 0)
{
printf("Client connect server failure:%s\n", strerror(errno));
con_status =0;
}
sqlite_init();
if(sqlite_table_exist(TABLE_NAME) == 0)
{
sqlite_create_table(TABLE_NAME);
}
//sqlite_delete(0, TABLE_NAME);
count = table_row_count(TABLE_NAME);
gettimeofday(&tv, NULL);
current_time = tv.tv_sec;
while(!g_sigstop)
{
gettimeofday(&tv, NULL);
last_time = tv.tv_sec;
sleep(2);
printf("\n\n\n");
if(SocketConnected(sockfd) == 0)
{
con_status = 0;
}
if((last_time - current_time) >= 30)
{
if((rv = temperature(&temp))< 0)
{
printf("Execute temperature failure!\n");
return -3;
}
last_time = getime(datime);
current_time = last_time;
memset(count_buffer, 0, sizeof(count_buffer));
sprintf(count_buffer, "%d", (count+1));
memset(temp_buffer, 0, sizeof(temp_buffer));
sprintf(temp_buffer, "%f", temp);
buftok[0] = count_buffer;
buftok[1] = "RPI1";
buftok[2] = datime;
buftok[3] = temp_buffer;
if(con_status)
{
if(sendata(sockfd, buftok) < 0)
{
sqlite_inset(buftok, TABLE_NAME);
count++;
con_status = 0;
close(sockfd);
}
}
else
{
//connfd = connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
connfd = client_socket_init();
if(connfd < 0)
{
printf("Client connect server failure:%s\n", strerror(errno));
con_status =0;
sqlite_inset(buftok, TABLE_NAME);
count++;
close(sockfd);
}
else
{
con_status =1;
if(sendata(sockfd, buftok) < 0)
{
sqlite_inset(buftok, TABLE_NAME);
count++;
close(sockfd);
}
}
}
}
else if(count >0)
{
if(con_status)
{
if(sendata2(sockfd,TABLE_NAME, count) < 0)
{
con_status = 0;
close(sockfd);
}
else
{
if(sqlite_delete(count, TABLE_NAME) == 0)
{
count--;
}
}
}
else
{
//connfd = connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
connfd = client_socket_init();
if(connfd < 0)
{
printf("Client connect server failure:%s\n", strerror(errno));
con_status = 0;
close(sockfd);
}
else
{
con_status = 1;
if(sendata2(sockfd, TABLE_NAME, count) < 0)
{
con_status = 0;
close(sockfd);
}
else
{
if(sqlite_delete(count, TABLE_NAME) == 0)
{
count--;
}
}
}
}
}
}
return 0;
}
static int sendata2_callback(void *data, int argc, char **argv, char **azColName)
{
memset(write_buffer2, 0, sizeof(write_buffer2));
sprintf(write_buffer2, "%s/%s/%s", argv[1], argv[2], argv[3]);
printf("write_buffer2:%s\n", write_buffer2);
return 0;
}
int sendata2(int sockfd, char *table_name, int count)
{
int write_rv2 = -1;
char sendata_buffer2[100];
memset(sendata_buffer2, 0, sizeof(sendata_buffer2));
sprintf(sendata_buffer2, "select * from %s limit 1 offset %d", table_name, (count-1));
rc = sqlite3_exec(db, sendata_buffer2, sendata2_callback, 0, &zErrMsg);
write_rv2 = write(sockfd, write_buffer2, strlen(write_buffer2));
if(write_rv2 < 0)
{
printf("Send data to sever failure:%s\n", strerror(errno));
return -1;
}
syslog(LOG_NOTICE, "Send data to sever successfully!\n");
return 0;
}
int sendata(int sockfd, char *buftok[])
{
int write_rv1 = -1;
char sendata_buffer1[100];
memset(sendata_buffer1, 0, sizeof(sendata_buffer1));
sprintf(sendata_buffer1, "%s/%s/%s", buftok[1], buftok[2], buftok[3]);
printf("sendata sendata_buffer1:%s\n", sendata_buffer1);
write_rv1 = write(sockfd, sendata_buffer1, strlen(sendata_buffer1));
if(write_rv1 < 0)
{
printf("Send data to sever failure:%s\n", strerror(errno));
return -1;
}
printf("Send data to sever successfully!\n");
return 0;
}
int sqlite_table_exist(char *table_name)
{
char table_exist[512];
sprintf(table_exist, "SELECT COUNT(*) FROM sqlite_master where type ='table' and name ='%s';", table_name);
rc = sqlite3_exec(db, table_exist, table_exist_callback, 0, &zErrMsg);
if(rc != SQLITE_OK)
{
printf("sqlite_table_exist:%s\n", zErrMsg);
sqlite3_free(zErrMsg);
exit(0);
}
if(iTableExist)
{
syslog(LOG_NOTICE, "%s is exist!\n", table_name);
return iTableExist;
}
else
{
return iTableExist;
}
}
static int table_exist_callback(void *data, int argc, char **argv, char **azColName)
{
if ( 1 == argc)
{
iTableExist = atoi(*(argv));
}
return 0;
}
int client_socket_init(void)
{
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd < 0)
{
printf("Create socket failure:%s\n", strerror(errno));
}
memset(&servaddr, 0 ,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(port);
servaddr.sin_addr.s_addr = inet_addr(ip_addr);
//printf("port:%d, ip_addr:%s, sockfd:%d\n", port, ip_addr, sockfd);
connfd = connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
return connfd;
}
double getime(char *datime)
{
gettimeofday(&tv, NULL);
last_time = tv.tv_sec;
st = localtime(&tv.tv_sec);
memset(datime, 0, sizeof(datime));
sprintf(datime, "%05d:%02d:%02d--%02d:%02d:%02d", st->tm_year, st->tm_mon, st->tm_mday, st->tm_hour, st->tm_min, st->tm_sec);
return last_time;
}
static int callback_row_count(void *NotUsed, int argc, char **argv, char **azColName)
{
count = atoi(argv[0]);
return 0;
}
int table_row_count(char *table_name)
{
char row_count[100];
sprintf(row_count, "SELECT COUNT(*) from %s", table_name);
rc = sqlite3_exec(db, row_count, callback_row_count, 0, &zErrMsg);
if( rc != SQLITE_OK )
{
printf("table_row_count: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}
else
{
return count;
}
}
int sqlite_delete(int id, char *table_name)
{
char sql_delete[100];
sprintf(sql_delete, "DELETE from %s where ID=%d;SELECT * from %s;", table_name, count, table_name);
//sql = "DELETE from COMPANY where ID=2; " \
// "SELECT * from COMPANY";
rc = sqlite3_exec(db, sql_delete, 0, 0, &zErrMsg);
if( rc != SQLITE_OK )
{
fprintf(stderr, "Sqlite_delete error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
return -1;
}
else
{
return 0;
}
}
void sqlite_inset(char *buftok[], char *table_name)
{
char sql_buffer[512];
char *ID1 = buftok[0];
char *SN1 = buftok[1];
char *DATIME1 = buftok[2];
char *TEMPERATURE1 = buftok[3];
printf("Inset data to TABLE %s: ", TABLE_NAME);
printf("ID1:%s ", buftok[0]);
printf("SN1:%s ", buftok[1]);
printf("DATIME1:%s ", buftok[2]);
printf("TEMPERATURE1:%s \n ", buftok[3]);
#if 0
syslog(LOG_NOTICE, "Inset data to TABLE %s: ", TABLE_NAME);
syslog(LOG_NOTICE, "ID1:%s ", buftok[0]);
syslog(LOG_NOTICE, "SN1:%s ", buftok[1]);
syslog(LOG_NOTICE, "DATIME1:%s ", buftok[2]);
syslog(LOG_NOTICE, "TEMPERATURE1:%s \n ", buftok[3]);
#endif
sprintf(sql_buffer, "INSERT INTO %s VALUES ('%s', '%s', '%s', '%s');" ,table_name, ID1, SN1, DATIME1, TEMPERATURE1);
rc = sqlite3_exec(db, sql_buffer, callback, 0, &zErrMsg);
if( rc != SQLITE_OK )
{
printf("Sqlite_inset: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}
else
{
syslog(LOG_NOTICE, "Last data inset table successfully\n");
}
return;
}
void sqlite_create_table(char *table_name)
{
char create_table[100];
sprintf(create_table, "CREATE TABLE %s(ID INT PRIMARY KEY, SN CHAR(10),DATIME CHAR(50),TEMPERATURE CHAR(10));", table_name);
rc = sqlite3_exec(db, create_table, callback, 0, &zErrMsg);
if(rc != SQLITE_OK)
{
printf("Sqlite_create_table:%s\n", zErrMsg);
sqlite3_free(zErrMsg);
exit(0);
}
else
{
syslog(LOG_NOTICE, "Table created successfully!\n");
}
return;
}
static int callback(void *NotUsed, int argc, char **argv, char **azColName)
{
int i;
for(i=0; i<argc; i++)
{
printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("\n");
return 0;
}
void sqlite_init(void)
{
rc = sqlite3_open("temperature.db", &db);
if(rc)
{
printf("Can't open database:%s\n", sqlite3_errmsg(db));
exit(0);
}
else
{
syslog(LOG_NOTICE, "Opened database successfully\n");
}
}
static inline void print_usage(char *programe)
{
printf("Usage:%s[OPTION]....\n", programe);
printf("-p[port]:Socket sever port address\n");
printf("-b[daemon]:Start daemon!\n");
printf("-h[help]:Display this help information\n");
printf("\nExample:%s -b -p 6667\n", programe);
return;
}
void signal_stop(int signum)
{
if(SIGUSR1 == signum)
{
printf("signum SIGUSR1 detected!\n");
}
else if(SIGUSR2 == signum)
{
printf("signum SIGUSR2 detected!\n");
}
g_sigstop = 1;
}
int SocketConnected(int sockfd)
{
if (sockfd <= 0)
return 0;
//struct tcp_info info;
int len = sizeof(info);
getsockopt(sockfd, IPPROTO_TCP, TCP_INFO, &info, (socklen_t *) & len);
if ((info.tcpi_state == 1)) {
printf("socket connected\n");
return 1;
} else {
printf("socket disconnected\n");
return 0;
}
}
int temperature (float *temp)
{
DIR *dir = NULL;
struct dirent *drt = NULL;
char *string = NULL;
int fd = -1;
char buf[512];
char *str;
char directory[100] = "/sys/bus/w1/devices/";
if((dir = opendir(directory)) == NULL)
{
printf("open directory %s failure:%s\n", directory, strerror(errno));
return -1;
}
while((drt = readdir(dir)) != NULL)
{
if(strstr(drt->d_name, "28-") != NULL)
{
string = drt->d_name;
break;
}
}
if(string == NULL)
{
printf("read directory name failure:%s\n", strerror(errno));
return -2;
}
string = strcat(directory, string);
string = strcat(directory, "/w1_slave");
fd = open(string, O_RDONLY);
if(fd < 0)
{
printf("open %s\n failure:%s\n", string, strerror(errno));
return -3;
}
memset(buf, 0, sizeof(buf));
if(read(fd, buf, sizeof(buf)) < 0)
{
printf("read data from w1_slave failure:%s\n", strerror(errno));
close(fd);
return -4;
}
if((str = strstr(buf, "t=")) == NULL)
{
printf("temperature not found:%s\n", strerror(errno));
close(fd);
return -5;
}
str = str +2;
*temp = atof(str)/1000;
syslog(LOG_NOTICE, "the temperature is %f\n", *temp);
close(fd);
return 0;
}
服务器端代码
/*********************************************************************************
* Copyright: (C) 2022 Zhang Changxing<ZhangChangxingVIP@163.com>
* All rights reserved.
*
* Filename: server.c
* Description: This file used to receive data sent by the device,and stored in the database.
*
* Version: 1.0.0(4/2/2022)
* Author: Zhang Changxing <ZhangChangxingVIP@163.com>
* ChangeLog: 1, Release initial version on "04/2/2022 15:45:31 PM"
*
********************************************************************************/
#include <stdio.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sqlite3.h>
#include <syslog.h>
#include <libgen.h>
#define MAX_EVENTS 512
#define TABLE_NAME "COMPANY29"
sqlite3 *db;
char *zErrMsg = 0;
int rc;
char *sql;
static int k = 0;
int *ptr = NULL;
int iTableExist = 0;
int connfd = -1;
static inline void print_usage(char *programe);
int socket_server_init(char *listen_ip, int port);
void set_socket_rimit(void);
static int callback(void *NotUsed, int argc, char **argv, char **azColName);
void sqlite_init(void);
void sqlite_create_table(char *table_name);
void sqlite_inset(char *buftok[], char *table_name);
int sqlite_table_exist(char *table_name);
static int table_exist_callback(void *data, int argc, char **argv, char **azColName);
int main (int argc, char **argv)
{
struct epoll_event event;
struct epoll_event event_array[MAX_EVENTS];
int listenfd;
char buf[1024];
int ch;
int port = 0;
int epollfd = -1;
int events = -1;
int daemon_run = 0;
int i;
int rev;
char *buftok[3];
int j;
char *p = NULL;
char *programe_name;
programe_name = basename(argv[0]);
struct option opts[] = {
{"port", required_argument, NULL, 'p'},
{"help", no_argument, NULL, 'b'},
{0, 0, 0, 0}
};
while((ch = getopt_long(argc, argv, "p:h", opts, NULL)) != -1)
{
switch(ch)
{
case 'b':
{
daemon_run = 1;
break;
}
case 'p':
{
port = atoi(optarg);
break;
}
case 'h':
{
print_usage(argv[0]);
break;
}
default:
{
printf("Invalid argument!\n");
return -1;
}
}
}
if(!port)
{
printf("The port is NULL!\n");
return -2;
}
if(daemon_run)
{
if(daemon(0, 0) < 0)
{
printf("Runing daemon failure:%s\n", strerror(errno));
return -3;
}
printf("Runing daemon successfully!\n");
}
openlog(programe_name, LOG_CONS|LOG_PID, 0);
set_socket_rimit();
listenfd = socket_server_init(NULL, port);
epollfd = epoll_create(MAX_EVENTS);
if(epollfd < 0 )
{
syslog(LOG_EMERG, "Create epoll failure:%s\n", strerror(errno));
return -4;
}
event.events = EPOLLIN;
event.data.fd = listenfd;
if((epoll_ctl(epollfd, EPOLL_CTL_ADD,listenfd, &event)) < 0)
{
syslog(LOG_EMERG, "Execute epoll_ctl failure:%s\n", strerror(errno));
return -5;
}
sqlite_init();
// if(sqlite_table_exist(TABLE_NAME) == 0)
// {
// sqlite_create_table(TABLE_NAME);
// }
while(1)
{
sleep(2);
events = epoll_wait(epollfd, event_array, MAX_EVENTS, -1);
for(i = 0; i < events--; i++)
{
if(event_array[i].events == EPOLLERR || event_array[i].events == EPOLLHUP)
{
syslog(LOG_WARNING, "Epoll wait eorr or hup!\n");
epoll_ctl(epollfd, EPOLL_CTL_DEL, event_array[i].data.fd,NULL);
close(event_array[i].data.fd);
}
if(event_array[i].data.fd == listenfd)
{
connfd = accept(listenfd, NULL, NULL);
if(connfd < 0)
{
syslog(LOG_WARNING, "Server connect new client failure:%s\n", strerror(errno));
close(connfd);
continue;
}
printf("Server connect new client[%d] successfully!\n", connfd);
event.events = EPOLLIN;
event.data.fd = connfd;
if((epoll_ctl(epollfd, EPOLL_CTL_ADD, connfd, &event)) < 0)
{
syslog(LOG_WARNING, "Add connfd to epollfd list failure:%s\n", strerror(errno));
close(event_array[i].data.fd);
continue;
}
}
else
{
memset(buf, 0, sizeof(buf));
rev = read(connfd, buf, sizeof(buf));
if(rev < 0)
{
syslog(LOG_WARNING, "Read data from client[%d] failure:%s\n", connfd, strerror(errno));
if(epoll_ctl(epollfd, EPOLL_CTL_DEL, event_array[i].data.fd, NULL) < 0 )
{
syslog(LOG_WARNING, "Delete connfd to epollfd list failure:%s\n", strerror(errno));
}
close(event_array[i].data.fd);
continue;
}
else if(rev == 0)
{
syslog(LOG_WARNING, "Client[%d] disconnect!\n", connfd);
continue;
}
p = strtok(buf, "/");
while(p)
{
buftok[j] = p;
++j;
p = strtok(NULL, "/");
}
if(sqlite_table_exist(buftok[0]) > 0)
{
sqlite_inset(buftok, buftok[0]);
}
else
{
sqlite_create_table(buftok[0]);
sqlite_inset(buftok, buftok[0]);
}
}
}
}
return 0;
}
void sqlite_inset(char *buftok[], char *table_name)
{
char sql_buffer[512];
char *SN1 = buftok[0];
char *DATIME1 = buftok[1];
char *TEMPERATURE1 = buftok[2];
printf("Accept client[%d] data successfully!\n", connfd);
printf("SN1:%s\n", buftok[0]);
printf("DATIME1:%s\n", buftok[1]);
printf("TEMPERATURE1:%s\n", buftok[2]);
sprintf(sql_buffer, "INSERT INTO %s VALUES ('%s', '%s', '%s');" ,table_name, SN1, DATIME1, TEMPERATURE1);
rc = sqlite3_exec(db, sql_buffer, callback, 0, &zErrMsg);
if( rc != SQLITE_OK )
{
syslog(LOG_WARNING, "sqlite_inset: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}
else
{
fprintf(stdout, "Records created successfully\n");
}
return;
}
int sqlite_table_exist(char *table_name)
{
char table_exist[512];
sprintf(table_exist, "SELECT COUNT(*) FROM sqlite_master where type ='table' and name ='%s';", table_name);
rc = sqlite3_exec(db, table_exist, table_exist_callback, 0, &zErrMsg);
if(rc != SQLITE_OK)
{
syslog(LOG_WARNING, "sqlite_table_exist:%s\n", zErrMsg);
sqlite3_free(zErrMsg);
exit(0);
}
if(iTableExist)
{
syslog(LOG_NOTICE, "%s is exist!\n", table_name);
return iTableExist;
}
else
{
return iTableExist;
}
}
static int table_exist_callback(void *data, int argc, char **argv, char **azColName)
{
if ( 1 == argc)
{
iTableExist = atoi(*(argv));
}
return 0;
}
void sqlite_create_table(char *table_name)
{
char create_table[100];
sprintf(create_table, "CREATE TABLE %s(SN CHAR(10),DATIME CHAR(50),TEMPERATURE CHAR(10));", table_name);
rc = sqlite3_exec(db, create_table, callback, 0, &zErrMsg);
if(rc != SQLITE_OK)
{
syslog(LOG_WARNING, "sqlite_create_table:%s\n", zErrMsg);
sqlite3_free(zErrMsg);
exit(0);
}
else
{
printf("Table created successfully!\n");
}
return;
}
static int callback(void *NotUsed, int argc, char **argv, char **azColName)
{
int i;
for(i=0; i<argc; i++)
{
printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("\n");
return 0;
}
void sqlite_init(void)
{
rc = sqlite3_open("temperature.db", &db);
if(rc)
{
syslog(LOG_NOTICE, "Can't open database:%s\n", sqlite3_errmsg(db));
exit(0);
}
else
{
fprintf(stderr, "Opened database successfully\n");
}
}
static inline void print_usage(char *programe)
{
printf("Usage:%s[OPTION]....\n", programe);
printf("-p[port]:Socket sever port address\n");
printf("-b[daemon]:Runing programe in background!\n");
printf("-h[help]:Display this help information\n");
printf("\nExample:%s -b -p 6667\n", programe);
return;
}
int socket_server_init(char *listen_ip, int port)
{
struct sockaddr_in servaddr;
int rv = -1;
int on = 1;
int listenfd = -1;
listenfd = socket(AF_INET, SOCK_STREAM, 0);
if(listenfd < 0)
{
syslog(LOG_EMERG, "Create socket failure:%s\n", strerror(errno));
rv = -1;
goto CleanUp;
}
setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on , sizeof(on));
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(port);
if(listen_ip == NULL)
{
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
}
else
{
if(inet_pton(AF_INET, listen_ip, &servaddr.sin_addr) < 0)
{
syslog(LOG_EMERG, "Execute inet_pton failure:%s\n", strerror(errno));
rv = -2;
goto CleanUp;
}
}
if((bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr))) < 0)
{
syslog(LOG_EMERG, "Bind the IP and port failure:%s\n", strerror(errno));
rv = -3;
goto CleanUp;
}
listen(listenfd, 50);
rv = listenfd;
goto CleanUp;
CleanUp:
if(rv > 0)
return listenfd;
else
return rv;
}
void set_socket_rimit(void)
{
struct rlimit limit;
getrlimit(RLIMIT_NOFILE, &limit);
limit.rlim_cur = limit.rlim_max;
setrlimit(RLIMIT_NOFILE, &limit);
return;
}
四、安装说明
1.客户端和服务器端安装数据库
sqlite3下载网址:http://www.sqlite.org/download.html
$ tar xvzf sqlite-autoconf-3071502.tar.gz
$ cd sqlite-autoconf-3071502
$ ./configure --prefix=/usr/local
$ make
$ make install
2.在树莓派上安装客户端
$ wget https://gitee.com/moqain/socket_ds18b20/tree/master/socket_client
3.在服务器上安装服务器端
$ wget https://gitee.com/moqain/socket_ds18b20/tree/master/socket_server
五、使用说明
1.编译运行服务器端
$ gcc server.c -o server -lsqlite3
$ ./server -p 端口号
2.编译运行客户端
$ gcc client.c -o client -lsqlite3
$ ./client -p 端口号 -i IP地址
六、本项目gitee仓库
https://gitee.com/moqain/socket_ds18b20/tree/master
整个项目需要用到的知识点比较,包括:Linux环境编程(socket通信、文件IO操作、多路复用、信号安装、系统日志等)、数据库操作,关于树莓派和传感器的硬件知识等。
其中需要注意的地方也比较多:
1.服务器端异常断开后,客户端的数据怎么办?
2.如何实时监测服务器是否断开?
3.在延时间隔时间,是否可以进行其他操作?
4.数据库或者表是否已经存在?
5.有多个客户端连接怎么办?
6.如何判断本次发送的数据是新采集的数据,还是存在数据库里面的数据?
7.服务器端是否需要为每个客户端创建一个表?