multi-threaded chat room
Service-Terminal:
Realize multi-user group chat function (the upper limit of the number of people can be set);
Messages sent by each user can be received by other users connected to the server;
The user enters "bye" to exit, and the server enters " quit " to exit.
There are three functions on the server
Main function main : server-side initialization, accepting connections;
Message processing function rcv_snd : Receive a message from a user, and send it to all other users after simple processing;
Exit function quit : When quit is entered , the server program terminates.
These three functions belong to three threads (to be precise, more than or equal to three). The Main function acts as the main thread and creates a thread where the exit function is located, and a thread that processes messages for this connection every time a new user is connected.
Client:
Establish a connection to the server, send and receive messages
The client has a total of two functions
Main function main : Initialize the client socket, establish a connection with the server, receive messages and display them locally
Send function snd : read the message from the console and send it to the server
These two functions run on two threads, one is the thread where the main function is located, and the other is the thread where the sending function created by the main function is located.
Attached:
Macro definition debug print switch
#define DEBUG_PRINT 1
#ifdef DEBUG_PRINT
#define DEBUG(format, ...) printf(“FILE: “__FILE__”, LINE: %d: “format”\n”, __LINE__, ##__VA_ARGS__)
#else
#define DEBUG(format, ...)
#endif
-lpthread is required when creating a thread when gcc compiles
Phtread_t thread; Pthread_creat(&thread, NULL, (void *)quit, NULL);
Pthread_creat(malloc(sizeof(pthread_t)), NULL, (void *)rcv_snd, (void *)i);
System time #include <time.h>
Time_t ticks = time(NULL); printf(“%s\n”, ctime(&ticks));
Server
Struct sockaddr_in serv_addr;
Bzero(&serv_addr, sizeof(serv_addr));
Serv_addr.sin_family = AF_INET;
Serv_addr.sin_port = htons(PORT);
Serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
Listenfd = socket (AF_INET, SOCK_STREAM, 0);
Bind(listenfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
Listen(listenfd, 10);
Int len = sizeof(cli_addr);
Connfd[i] = accept(listenfd, (struct sockaddr *)&cli_addr, &len);
client
Struct sockaddr_in serv_addr;
Bzero(&serv_addr, sizeof(serv_addr));
Serv_addr.sin_family = AF_INET;
Serv_addr.sin_port = htons(PORT);
Inet_pton(IP, &serv_addr.sin_addr);
Sockfd = socket (AF_INET, SOCK_STREAM, 0);
Connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
source code server.c
1 #include <stdio.h>
2 #include <stdlib.h> // exit
3 #include <string.h>
4 #include <unistd.h> // bind listen
5 #include <time.h> // time(NULL) ctime(&ticks)
6 #include <netinet/in.h>
7 #include <arpa/inet.h> // must be included for inet_ntop
8
9 #define PORT 8000
10 #define MAXMEM 10
11 #define BUFFSIZE 128
12
13 //#define DEBUG_PRINT 1 // Macro definition debug switch
14 #ifdef DEBUG_PRINT
15 #define DEBUG(format, ...) printf("FILE: "__FILE__", LINE: %d: "format"\n", __LINE__, ##__VA_ARGS__)
16 #else
17 #define DEBUG(format, ...)
18 #endif
19
20 int listenfd, connfd[MAXMEM];
21
22 void quit();
23 void rcv_snd(int p);
24
25 int main()
26 {
27 struct sockaddr_in serv_addr, cli_addr;
28 // int len = sizeof(cli_addr), i;
29 int i;
30 time_t ticks;
31 pthread_t thread;
32 char buff[BUFFSIZE];
33
34 printf("running...\n(Prompt: enter command ""quit"" to exit server)\n");
35 DEBUG("=== initialize..."); // Initialize and fill the server address structure
36 bzero(&serv_addr, sizeof(struct sockaddr_in));
37 serv_addr.sin_family = AF_INET;
38 serv_addr.sin_port = htons(PORT);
39 serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
40
41 DEBUG("=== socket..."); // socket creates a listening socket on the server side
42 listenfd = socket (AF_INET, SOCK_STREAM, 0);
43 if(listenfd < 0)
44 {
45 perror("fail to socket");
46 exit(-1);
47 }
48
49 DEBUG("=== bind..."); // bind binds the socket to the populated address structure
50 if(bind(listenfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
51 {
52 perror("fail to bind");
53 exit(-2);
54 }
55
56 DEBUG("=== listening..."); // listen turns an actively connected socket into a passive listening socket
57 listen(listenfd, MAXMEM);
58
59 /* === Create a thread, manage the server program, and call the quit function === */
60 pthread_create(&thread, NULL, (void *)(quit), NULL);
61
62 // Initialize the socket descriptor array to -1, indicating idle
63 for(i=0; i<MAXMEM; i++)
64 connfd[i] = -1;
65
66 while(1)
67 {
68 int len;// = sizeof(cli_addr);
69 for(i=0; i<MAXMEM; i++)
70 {
71 if(connfd[i] == -1)
72 break;
73 }
74 // accept gets a connection from the connection queue accepted by listen
75 connfd[i] = accept(listenfd, (struct sockaddr *)&cli_addr, &len);
76 if(connfd[i] < 0)
77 {
78 perror("fail to accept");
79 // continue; // This sentence can be omitted, accept will block and wait
80 }
81 ticks = time(NULL);
82 //sprintf(buff, "%.24s\r\n", ctime(&ticks));
83 printf("%.24s\n\tconnect from: %s, port %d\n",
84 ctime(&ticks), inet_ntop(AF_INET, &(cli_addr.sin_addr), buff, BUFFSIZE),
85 ntohs(cli_addr.sin_port)); // Note the use of inet_ntop, #include <arpa/inet.h>
86
87 /* === Create a thread for the current socket and process messages from the current socket === */
88 pthread_create(malloc(sizeof(pthread_t)), NULL, (void *)(&rcv_snd), (void *)i);
89 }
90 return 0;
91 }
92
93 void quit()
94 {
95 char msg[10];
96 while(1)
97 {
98 scanf("%s", msg); // scanf, unlike fgets, does not read the last newline entered
99 if(strcmp(msg, "quit") == 0)
100 {
101 printf("Byebye... \n");
102 close(listenfd);
103 exit(0);
104 }
105 }
106 }
107
108 void rcv_snd(int n)
109 {
110 int len, i;
111 char name[32], mytime[32], buf[BUFFSIZE];
112 time_t ticks;
113 int ret;
114
115 // Get the name of the socket user corresponding to this thread
116 write(connfd[n], "your name: ", strlen("your name: "));
117 len = read(connfd[n], name, 32);
118 if(len > 0)
119 name[len-1] = '\0'; // strip newline
120 strcpy(buf, name);
121 strcat(buf, "\tjoin in\n\0");
122 // Tell all users that the current user has joined
123 for(i=0; i<MAXMEM; i++)
124 {
125 if(connfd[i] != -1)
126 write(connfd[i], buf, strlen(buf));
127 }
128
129 while(1)
130 {
131 char temp[BUFFSIZE];
132 if((len=read(connfd[n], temp, BUFFSIZE)) > 0)
133 {
134 temp[len-1] = '\0';
135 // When the user enters bye, the current user exits
136 if(strcmp(temp, "bye") == 0)
137 {
138 close(connfd[n]);
139 connfd[n] = -1;
140 pthread_exit(&ret);
141 }
142 ticks = time(NULL);
143 sprintf(mytime, "%.24s\r\n", ctime(&ticks));
144 //write(connfd[n], mytime, strlen(mytime));
145 strcpy(buf, name);
146 strcat(buf, "\t");
147 strcat(buf, mytime);
148 strcat(buf, "\r\t");
149 strcat(buf, temp);
150 strcat(buf, "\n");
151
152 for(i=0; i<MAXMEM; i++)
153 {
154 if(connfd[i] != -1)
155 write(connfd[i], buf, strlen(buf));
156 }
157 }
158 }
159
160 }
source code client.c
1 /*
2 * FILE: client.c
3 * DATE: 20180206
4 * ==============
5 */
6
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10
11 #include <netinet/in.h>
12
13 #define BUFFSIZE 128
14 #define HOST_IP "192.168.159.3"
15 #define PORT 8000
16
17 int sockfd;
18
19 void snd();
20
21 int main()
22 {
23 pthread_t thread; // pthread_t thread, add -lpthread when gcc compiles
24 struct sockaddr_in serv_addr; // struct sockaddr_in
25 char buf[BUFFSIZE];
26 // Initialize the server address structure
27 bzero(&serv_addr, sizeof(struct sockaddr_in)); // bzero 清零
28 serv_addr.sin_family = AF_INET; // sin_family AF_INET
29 serv_addr.sin_port = htons(PORT); // sin_port htons(PORT)
30 inet_pton(HOST_IP, &serv_addr.sin_addr); // inet_pton
31 // Create client socket
32 sockfd = socket(AF_INET, SOCK_STREAM, 0); // socket creates a socket
33 if(sockfd < 0)
34 {
35 perror("fail to socket");
36 exit(-1);
37 }
38 // Establish a connection with the server
39 printf("connecting... \n");
40 if(connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) // connect
41 {
42 perror("fail to connect");
43 exit(-2);
44 }
45 /* === The program is divided into two threads from here === */
46 // Create a thread that sends a message and call the function snd that sends a message
47 pthread_create(&thread, NULL, (void *)(&snd), NULL); // pthread_create
48 // Thread receiving message
49 while(1)
50 {
51 int len;
52 if((len=read(sockfd, buf, BUFFSIZE)) > 0) // read reads the communication socket
53 {
54 buf[len] = '\0'; // Add a terminator to avoid displaying the content left in the buffer
55 printf("\n%s", buf);
56 fflush(stdout); // fflush flushes standard output to ensure timely display of content
57 }
58 }
59 return 0;
60 }
61
62 // function to send message
63 void snd()
64 {
65 char name[32], buf[BUFFSIZE];
66
67 fgets(name, 32, stdin); // fgets will read the newline after the input string
68 write(sockfd, name, strlen(name)); // write writes to the communication socket
69 while(1)
70 {
71 fgets(buf, BUFFSIZE, stdin);
72 write(sockfd, buf, strlen(buf));
73 if(strcmp(buf, "bye\n") == 0) // Note the \n here
74 exit(0);
75 }
76 }