select 函数 实现三个客户端异步通信

1 //建立管道
2 mkfifo 12 13 21 23 31 32

 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/time.h>
 9 #include<sys/select.h>
10  #include <sys/select.h>
11 
12        /* According to earlier standards */
13        #include <sys/time.h>
14        #include <sys/types.h>
15        #include <unistd.h>
16 
17 int main(int argc, char* argv[])//21
18 {
19 
20     int fd21, fd31,fd12,fd13 ;
21     fd21 = open("21", O_RDONLY);
22     fd31 = open("31", O_RDONLY);
23 
24     fd12 = open("12",O_WRONLY);
25 
26     fd13 = open("13",O_WRONLY);
27     printf("OK!\n");
28 
29 
30     printf("OK!\n");
31     fd_set read_sets ;
32     fd_set write_sets ;
33     int iret,iwrt ;
34     char buf[1024] ;
35     struct timeval tm ;
36     while(1)
37     {
38 
39         tm.tv_sec = 1 ;
40         tm.tv_usec = 0 ;
41         FD_ZERO(&read_sets);
42         FD_ZERO(&write_sets);
43 
44         FD_SET(fd21, &read_sets);
45         FD_SET(fd31, &read_sets);
46         FD_SET( 0, &write_sets);
47         //FD_SET(fd12, &write_sets);
48         //FD_SET(fd13, &write_sets);
49 
50         iret = select(10, &read_sets, NULL, NULL, &tm);
51         iwrt = select(10,&write_sets,NULL,NULL,&tm);
52 
53         //读
54         if(iret != 0)
55         {
56             printf("active: %d\n", iret);
57 
58             if(FD_ISSET(fd21, &read_sets))
59             {
60                 memset(buf, 0, 1024);
61                 read(fd21, buf, 1023);
62                 printf("from 2: %s\n", buf);
63             }
64             if(FD_ISSET(fd31, &read_sets))
65             {
66                 memset(buf, 0, 1024);
67                 read(fd31, buf, 1023);
68                 printf("from 3: %s\n", buf);
69             }
70         }
71 
72 
73         // write
74         if(iwrt != 0)
75         {
76             printf("active: %d\n", iwrt);
77             if(FD_ISSET( 0 /*fd12*/, &write_sets))
78             {
79                 memset(buf, 0, 128);
80                 read(0, buf, 127) ;
81                 write(fd12, buf, strlen(buf));
82                 write(fd13, buf, strlen(buf));
83             }
84             /*if(FD_ISSET(fd13, &write_sets))
85             {
86                 memset(buf, 0, 128);
87                 read(0, buf, 127) ;
88                 write(fd13, buf, strlen(buf));
89             }*/
90         }
91 
92     }
93     return 0 ;
94 }

 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 int main(int argc, char* argv[])//21
10 {
11     int fd12, fd32,fd21,fd23 ;
12     fd21 = open("21",O_WRONLY);
13 
14     fd12 = open("12", O_RDONLY);
15     fd32 = open("32", O_RDONLY);
16 
17     fd23 = open("23",O_WRONLY);
18 
19 
20     fd_set read_sets ,write_sets ;
21     int iret ,iwrt;
22     char buf[1024] ;
23     struct timeval tm ;
24     while(1)
25     {
26 
27         tm.tv_sec = 1 ;
28         tm.tv_usec = 0 ;
29         FD_ZERO(&read_sets);
30         FD_ZERO(&write_sets);
31         FD_SET(fd12, &read_sets);
32         FD_SET(fd32, &read_sets);
33         FD_SET( 0, &write_sets);
34         //FD_SET(fd21,&write_sets);
35         //FD_SET(fd23,&write_sets);
36 
37         iret = select(10, &read_sets, NULL, NULL, &tm);
38             iwrt = select(10,&write_sets,NULL,NULL,&tm);
39 
40         if(iret != 0)
41         {
42             printf("active: %d\n", iret);
43 
44             if(FD_ISSET(fd12, &read_sets))
45             {
46                 memset(buf, 0, 1024);
47                 read(fd12, buf, 1023);
48                 printf("from 1: %s\n", buf);
49             }
50             if(FD_ISSET(fd32, &read_sets))
51             {
52                 memset(buf, 0, 1024);
53                 read(fd32, buf, 1023);
54                 printf("from 3: %s\n", buf);
55             }
56         }
57 
58 
59         // write
60         if(iwrt != 0)
61         {
62             printf("active: %d\n", iwrt);
63             if(FD_ISSET( 0 , &write_sets))
64             {
65                 memset(buf, 0, 128);
66                 read(0, buf, 127) ;
67                 write(fd21, buf, strlen(buf));
68                 write(fd23, buf, strlen(buf));
69             }
70         /*    if(FD_ISSET(fd23, &write_sets))
71             {
72                 memset(buf, 0, 128);
73                 read(0, buf, 127) ;
74                 write(fd23, buf, strlen(buf));
75             }*/
76         }
77 
78     }
79     return 0 ;
80 }

 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 int main(int argc, char* argv[])//31
10 {
11     int fd13, fd23,fd31,fd32 ;
12     fd31 = open("31",O_WRONLY);
13 
14     fd32 = open("32",O_WRONLY);
15 
16     fd13 = open("13", O_RDONLY);
17     fd23 = open("23", O_RDONLY);
18 
19     printf("OK!\n");
20     fd_set read_sets ,write_sets ;
21     int iret,iwrt ;
22     char buf[1024] ;
23     struct timeval tm ;
24     while(1)
25     {
26 
27         tm.tv_sec = 1 ;
28         tm.tv_usec = 0 ;
29         FD_ZERO(&read_sets);
30         FD_ZERO(&write_sets);
31         FD_SET(fd13, &read_sets);
32         FD_SET(fd23, &read_sets);
33         //FD_SET(fd31,&write_sets);
34         //FD_SET(fd32,&write_sets);
35         FD_SET( 0, &write_sets);
36 
37         iret = select(10, &read_sets, NULL, NULL, &tm);
38         iwrt = select(10,&write_sets,NULL,NULL,&tm);
39 
40         //读
41     if(iret != 0)
42         {
43             printf("active: %d\n", iret);
44 
45             if(FD_ISSET(fd13, &read_sets))
46             {
47                 memset(buf, 0, 1024);
48                 read(fd13, buf, 1023);
49                 printf("from 1: %s\n", buf);
50             }
51             if(FD_ISSET(fd23, &read_sets))
52             {
53                 memset(buf, 0, 1024);
54                 read(fd23, buf, 1023);
55                 printf("from 2: %s\n", buf);
56             }
57         }
58 
59 
60         // write
61         if(iwrt != 0)
62         {
63             printf("active: %d\n", iwrt);
64             if(FD_ISSET( 0 , &write_sets))
65             {
66                 memset(buf, 0, 128);
67                 read(0, buf, 127) ;
68                 write(fd31, buf, strlen(buf));
69                  write(fd32, buf, strlen(buf));
70             }
71             /*if(FD_ISSET(fd32, &write_sets))
72             {
73                 memset(buf, 0, 128);
74                 read(0, buf, 127) ;
75                 write(fd32, buf, strlen(buf));
76             }*/
77         }
78     }
79 
80     return 0 ;
81 }