拓扑结构：
各个客户端创建读写管道，通过“上下线信息管道”向服务器发送上下线信息和读写管道名称。服务器接受信息，修改链表（存储客户端信息）。客户端、服务器打开读写管道，服务器通过“W”管道接收从客户端发来的信息，在根据链表同个其他各个“R”管道向其他客户端发送信息。
具体流程：
1、建立上下线信息管道
服务器：
1 mkfifo(path_name, 0666);// 创建管道 —— 专用于接收客户端上下线信息
2
3 printf("mkfifo over!\n");
4
5 fd_listen = open(path_name, O_RDONLY);
6 if(fd_listen == -1)
7 {
8 printf("open server_fifo fail!\n");
9 exit(1);
10 }
客户端：
1 //打开上下线管道
2 int fd_server ;
3 char path_name[128]="";
4 char fifo_name[128] ;
5 char msg[1024] ="" ;
6 char fifo1[128], fifo2[128] ;
7 int fd_recv, fd_send ;
8 sprintf(path_name, "%s/%s", PIPE_PATH, PIPE_NAME);
9
10 fd_server = open(path_name, O_WRONLY);
11 if(fd_server == -1)
12 {
13 printf("open fail!\n");
14 exit(1) ;
15 }
2、客户端建立读写管道
// 建造读写管道 pid_r.fifo pid_w.fifo
//
memset(fifo_name, 0, 128);
sprintf(fifo_name, "%u_r.fifo", getpid());
memset(path_name, 0, sizeof(path_name));
sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
strcpy(fifo1, path_name);
if(-1 == mkfifo(path_name, 0666) )
{
printf("mkfif fail: %s\n", path_name);
exit(1) ;
}
printf("%s open\n", path_name);
memset(fifo_name, 0, 128);
sprintf(fifo_name, "%u_w.fifo", getpid());
memset(path_name, 0, sizeof(path_name));
sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
strcpy(fifo2, path_name);
if(mkfifo(path_name, 0666) == -1 )
{
printf("mkfif fail: %s\n", path_name);
exit(1) ;
}
printf("%s open\n", path_name);
printf("mkfifo over!\n");
3、上线处理
客户端发送上线信息：
1 //发送上线信息
2 sprintf(msg, "%u on\n", getpid());
3 printf("msg: %s\n", msg);
4 write(fd_server, msg, strlen(msg));
服务器监听到后处理：
1 // 读写是针对客户端而言的： pid_r.fifo(c_r - s_w) pid_w.fifo(c_w - s_r)
2 printf("client: %d on\n", client_pid);
3 //pid_r.fifo s_w
4 //构建管道名字符串
5 memset(fifo_name, 0, 128) ;
6 sprintf(fifo_name, "%d_r.fifo", client_pid);
7 memset(path_name, 0, 128) ;
8 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
9
10 //新增链表节点
11 pnew = (pCLIENT)calloc(1, sizeof(CLIENT));
12 pnew ->m_id = client_pid ;
13 printf("pid_r.fifo: %s\n", path_name);
14 pnew ->m_send = open(path_name, O_WRONLY);
15 printf("send_fd: %d\n", pnew ->m_send);
16
17 //打开“W”管道 pid_w.fifo s_r
18 memset(fifo_name, 0, 128) ;
19 sprintf(fifo_name, "%d_w.fifo", client_pid);
20 memset(path_name, 0, 128) ;
21 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
22
23
24 printf("pid_w.fifo: %s\n", path_name);
25 pnew ->m_recv = open(path_name, O_RDONLY);
26 printf("recv_fd: %d\n", pnew ->m_recv);
27 printf("open client fifo: %d, %d\n", pnew ->m_send, pnew ->m_recv);
28
29
30 FD_SET(pnew ->m_recv, &rd_sets);//把pid_w.fifo 句柄 加到读集合中去 主要：更新的是读集合，而不是副本集合
31
32 pnew ->m_next = plist ; //插入链表
33 plist = pnew ;
客户端也打开管道：
1 memset(fifo_name, 0, 128);
2 sprintf(fifo_name, "%u_r.fifo", getpid());
3 memset(path_name, 0, sizeof(path_name));
4 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
5
6 fd_recv = open(path_name, O_RDONLY);
7
8 memset(fifo_name, 0, 128);
9 sprintf(fifo_name, "%u_w.fifo", getpid());
10 memset(path_name, 0, sizeof(path_name));
11 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
12
13 fd_send = open(path_name, O_WRONLY);
14
15 printf("fifo open %d %d\n", fd_send, fd_recv);
4、客户端、服务器对通信信息处理
客户端监听到键盘的输入信息，则转发给服务器：
1 if(FD_ISSET(0, &rd_sets))
2 {
3 memset(msg, 0, sizeof(msg)) ;
4 sprintf(msg, "from %u: ", getpid());
5 write(fd_send, msg, strlen(msg));
6
7 }
客户端监听服务器发来的信息，并打印：
1 if(FD_ISSET(fd_recv, &rd_sets))
2 {
3 memset(msg, 0, sizeof(msg)) ;
4 read(fd_recv, msg, 1024);
5 write(1, msg, strlen(msg));
6 }
服务器监听到客户端发来的信息，根据链表内客户端的信息，进行转发：
1 //2、遍历链表，监听其他的管道文件（用于服务器和客户端通信）句柄
2 pcur = plist ;
3 while(pcur)
4 {
5 if(FD_ISSET(pcur ->m_recv, &bak_sets))// translate
6 {
7 memset(msg, 0, 1024);
8 read(pcur -> m_recv, msg, 1024);
9
10 dispatch_msg(plist,pcur, msg);
11 }
12 pcur = pcur ->m_next ;
13 }
1 void dispatch_msg(pCLIENT phead,pCLIENT pcur, char* msg)
2 {
3 while(phead)
4 {
5 if(phead!=pcur)
6 write(phead ->m_send, msg, strlen(msg));
7 phead = phead ->m_next ;
8 }
9 }
完整代码
server：
1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<string.h>
4 #include<unistd.h>
5 #include<sys/stat.h>
6 #include<sys/types.h>
7 #include<fcntl.h>
8 #include<sys/select.h>
9 #include<sys/time.h>
10 #define PIPE_PATH "/home/soso/Desktop/2-17/FIFO"
11 #define PIPE_NAME "server.fifo"
12 typedef struct tag
13 {
14 int m_id ;
15 int m_send;
16 int m_recv;
17 struct tag* m_next ;
18 }CLIENT, *pCLIENT;
19
20
21 void dispatch_msg(pCLIENT phead,pCLIENT pcur, char* msg)
22 {
23 while(phead)
24 {
25 if(phead!=pcur)
26 write(phead ->m_send, msg, strlen(msg));
27 phead = phead ->m_next ;
28 }
29 }
30
31 int main(int argc, char* argv[])
32 {
33 int fd_listen ; //文件句柄
34 char path_name[128] = "" ;
35 char fifo_name[128] ;
36 char msg[1024];
37
38 char client_stat[5] = "";//客户端状态
39 int client_pid ; // 客户端进程ID
40 sprintf(path_name, "%s/%s", PIPE_PATH, PIPE_NAME);//路径名 = 路径/管道名
41
42 mkfifo(path_name, 0666);// 创建管道 —— 专用于接收客户端上下线信息
43
44 printf("mkfifo over!\n");
45
46 fd_listen = open(path_name, O_RDONLY);
47 if(fd_listen == -1)
48 {
49 printf("open server_fifo fail!\n");
50 exit(1);
51 }
52
53
54 pCLIENT plist = NULL, pcur, pnew, ppre ;
55
56 fd_set rd_sets, bak_sets; //读集合 和 备份读集合
57 FD_ZERO(&rd_sets);//初始化清空
58 FD_ZERO(&bak_sets);
59 FD_SET(fd_listen, &rd_sets); //将fd_listen句柄 加入到 读集合
60 while(1)
61 {
62 bak_sets = rd_sets ;//每次循环更新副本集合
63 printf("selecting...\n");
64 select(1024, &bak_sets, NULL, NULL, NULL);//监听集合
65
66 //1、监听fd_listen 管道文件句柄（专用于服务器接收客户端上下线信息）
67 if(FD_ISSET(fd_listen, &bak_sets)) //若监听到 fd_listen
68 {
69 memset(msg,0, 1024);
70 if( read(fd_listen, msg, 1024) == 0 ) //读取管道信息；但没有客户端 write的时候，read的返回值是0
71 {
72 printf("no clients!\n");
73 continue ;
74 }
75
76 memset(client_stat, 0, sizeof(client_stat));
77 sscanf(msg, "%d%s", &client_pid, client_stat);//信息格式：“client_pid client_stat\n”
78 if(strncmp("on", client_stat, 2) == 0)//client on"pid on\n"
79 {// 读写是针对客户端而言的： pid_r.fifo(c_r - s_w) pid_w.fifo(c_w - s_r)
80 printf("client: %d on\n", client_pid);
81 //pid_r.fifo s_w
82 //构建管道名字符串
83 memset(fifo_name, 0, 128) ;
84 sprintf(fifo_name, "%d_r.fifo", client_pid);
85 memset(path_name, 0, 128) ;
86 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
87
88 //新增链表节点
89 pnew = (pCLIENT)calloc(1, sizeof(CLIENT));
90 pnew ->m_id = client_pid ;
91 printf("pid_r.fifo: %s\n", path_name);
92 pnew ->m_send = open(path_name, O_WRONLY);
93 printf("send_fd: %d\n", pnew ->m_send);
94
95 //pid_w.fifo s_r
96 memset(fifo_name, 0, 128) ;
97 sprintf(fifo_name, "%d_w.fifo", client_pid);
98 memset(path_name, 0, 128) ;
99 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
100
101
102 printf("pid_w.fifo: %s\n", path_name);
103 pnew ->m_recv = open(path_name, O_RDONLY);
104 printf("recv_fd: %d\n", pnew ->m_recv);
105 printf("open client fifo: %d, %d\n", pnew ->m_send, pnew ->m_recv);
106
107
108 FD_SET(pnew ->m_recv, &rd_sets);//把pid_w.fifo 句柄 加到读集合中去 主要：更新的是读集合，而不是副本集合
109
110 pnew ->m_next = plist ; //插入链表
111 plist = pnew ;
112
113 }else//client off "pid off\n"
114 {
115 printf("client: %d off\n", client_pid);
116 ppre = NULL ;//前驱指针
117 pcur = plist ;
118 while(pcur && pcur ->m_id != client_pid) //遍历到该客户端PID
119 {
120 ppre = pcur ;
121 pcur = pcur ->m_next ;
122 }
123
124
125 if(pcur == NULL)
126 {
127 printf("not exist!\n");
128 continue ;
129 }else
130 {
131 //删除节点
132 if(ppre == NULL)
133 {
134 plist = pcur ->m_next ;
135 }else
136 {
137 ppre ->m_next = pcur ->m_next ;
138 }
139
140 //关闭文件
141 close(pcur ->m_send) ;
142 close(pcur ->m_recv) ;
143
144 //把 pcur ->m_recv 从读集合中删除
145 FD_CLR(pcur ->m_recv, &rd_sets);
146
147 free(pcur); //释放内存
148 printf("clear ok !\n");
149
150 }
151 }
152 }
153
154 //2、遍历链表，监听其他的管道文件（用于服务器和客户端通信）句柄
155 pcur = plist ;
156 while(pcur)
157 {
158 if(FD_ISSET(pcur ->m_recv, &bak_sets))// translate
159 {
160 memset(msg, 0, 1024);
161 read(pcur -> m_recv, msg, 1024);
162
163 dispatch_msg(plist,pcur, msg);
164 }
165 pcur = pcur ->m_next ;
166 }
167 }
168 return 0 ;
169 }
client：
1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<string.h>
4 #include<unistd.h>
5 #include<sys/stat.h>
6 #include<sys/types.h>
7 #include<fcntl.h>
8 #include<sys/select.h>
9 #include<sys/time.h>
10 #define PIPE_PATH "/home/soso/Desktop/2-17/FIFO"
11 #define PIPE_NAME "server.fifo"
12 int main(int argc, char* argv[])
13 {
14 //1、向服务器通知上线下线信息
15
16 //打开上下线管道
17 int fd_server ;
18 char path_name[128]="";
19 char fifo_name[128] ;
20 char msg[1024] ="" ;
21 char fifo1[128], fifo2[128] ;
22 int fd_recv, fd_send ;
23 sprintf(path_name, "%s/%s", PIPE_PATH, PIPE_NAME);
24
25 fd_server = open(path_name, O_WRONLY);
26 if(fd_server == -1)
27 {
28 printf("open fail!\n");
29 exit(1) ;
30 }
31
32
33
34 // 建造读写管道 pid_r.fifo pid_w.fifo
35 //
36 memset(fifo_name, 0, 128);
37 sprintf(fifo_name, "%u_r.fifo", getpid());
38 memset(path_name, 0, sizeof(path_name));
39 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
40
41 strcpy(fifo1, path_name);
42 if(-1 == mkfifo(path_name, 0666) )
43 {
44 printf("mkfif fail: %s\n", path_name);
45 exit(1) ;
46 }
47
48 printf("%s open\n", path_name);
49
50 memset(fifo_name, 0, 128);
51 sprintf(fifo_name, "%u_w.fifo", getpid());
52 memset(path_name, 0, sizeof(path_name));
53 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
54
55 strcpy(fifo2, path_name);
56 if(mkfifo(path_name, 0666) == -1 )
57 {
58
59 printf("mkfif fail: %s\n", path_name);
60 exit(1) ;
61 }
62 printf("%s open\n", path_name);
63
64 printf("mkfifo over!\n");
65
66
67 //发送上线信息
68 sprintf(msg, "%u on\n", getpid());
69 printf("msg: %s\n", msg);
70
71 write(fd_server, msg, strlen(msg));
72
73 //
74 memset(fifo_name, 0, 128);
75 sprintf(fifo_name, "%u_r.fifo", getpid());
76 memset(path_name, 0, sizeof(path_name));
77 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
78
79 fd_recv = open(path_name, O_RDONLY);
80
81 memset(fifo_name, 0, 128);
82 sprintf(fifo_name, "%u_w.fifo", getpid());
83 memset(path_name, 0, sizeof(path_name));
84 sprintf(path_name, "%s/%s", PIPE_PATH, fifo_name);
85
86 fd_send = open(path_name, O_WRONLY);
87
88 printf("fifo open %d %d\n", fd_send, fd_recv);
89
90 fd_set rd_sets ;
91 FD_ZERO(&rd_sets);
92 while(1)
93 {
94 FD_SET(0, &rd_sets);
95 FD_SET(fd_recv, &rd_sets);
96
97 select(1024, &rd_sets, NULL, NULL, NULL);
98
99 if(FD_ISSET(0, &rd_sets))
100 {
101 memset(msg, 0, sizeof(msg)) ;
102 sprintf(msg, "from %u: ", getpid());
103 if(read(0, msg + strlen(msg), 1024 - strlen(msg) ) == 0)
104 {
105 printf("off!\n");
106 memset(msg, 0, sizeof(msg));
107 sprintf(msg, "%d off\n", getpid());
108 write(fd_server, msg, strlen(msg));
109
110 close(fd_send);
111 close(fd_recv);
112
113 unlink(fifo1);
114 unlink(fifo2);
115 break ;
116 }
117 write(fd_send, msg, strlen(msg));
118
119 }
120 if(FD_ISSET(fd_recv, &rd_sets))
121 {
122 memset(msg, 0, sizeof(msg)) ;
123 read(fd_recv, msg, 1024);
124 write(1, msg, strlen(msg));
125 }
126 }
127 }
时间： 2024-10-10 16:28:13