linux下实现两人、三人无序对话功能

 对于两个程序之间的进行交互式

 

本程序主要通过父进程创建两个子进程,通过管道来实现,和两人无序对话的功能一样。只要逻辑清晰,并不难。共需要pipe(有名管道)六根,功能为用于读、写,为了使逻辑清晰,方便讨论,以下1、2、3分别代表程序1、2、3之间的管道,分别对程序之间的管道进项讨论分析:  

A B C
1-2 write 1-2 read 1-3 read
1-3 write 2-1 write 3-1 write
2-1 read 2-3 write 2-3 read
3-1 read 3-2 read 3-2 write
 以上表格表示的具体含义我在这里举例说明一下。eg:对于A(聊天猪头)而言共有四根管道与其相连,两根用于读,另外两根用于写,1-2管道代表A、B之间的管道A需要进行写操作,而B进行读操作。 
  • A:第一人
 1 /*============================================
 2   > Copyright (C) 2014 All rights reserved.
 3   > FileName:1.c
 4   > author:donald
 5   > date:2014/08/22/ 20:28:53
 6   > details:
 7 ==============================================*/
 8 
 9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <sys/types.h>
13 #include <sys/stat.h>
14 #include <fcntl.h>
15 #define N 1024
16 int main(int argc, const char *argv[])//12,13,21,31
17 {
18     if(mkfifo(argv[1],0666) == -1 || mkfifo(argv[2],0666) == -1){
19         perror("mkfifo");
20         exit(1);
21     }
22 
23     int fd_12,fd_13,fd_21,fd_31;
24     char buf[N];
25     fd_12 = open(argv[1],O_WRONLY);
26     fd_13 = open(argv[2],O_WRONLY);
27     fd_21 = open(argv[3],O_RDONLY);
28     fd_31 = open(argv[4],O_RDONLY);
29 
30     printf("open  sucess\n");
31 
32     if(fork() == 0){//21  r
33         close(fd_13);
34         close(fd_12);
35         close(fd_31);
36         while(memset(buf,0,N),read(fd_21,buf,N) != 0){
37             printf("from 2:");
38             write(1,buf,strlen(buf));
39         }
40         close(fd_21);
41         exit(1);
42     }
43     if(fork() == 0){//31  r
44         close(fd_13);
45         close(fd_12);
46         close(fd_21);
47         while(memset(buf,0,N),read(fd_31,buf,N) != 0){
48             printf("from 3:");
49             write(1,buf,strlen(buf));
50         }
51         close(fd_31);
52         exit(1);
53     }
54 
55     //12 13  w
56     close(fd_21);
57     close(fd_31);
58     while(memset(buf,0,N),fgets(buf,N,stdin) != NULL){
59         write(fd_13,buf,strlen(buf));
60         write(fd_12,buf,strlen(buf));
61     }
62     close(fd_13);
63     close(fd_12);
64     wait(NULL);
65     wait(NULL);
66 
67     unlink(argv[1]);
68     unlink(argv[2]);
69     printf("program 1 over\n");
70     return 0;
71 }
1.c
  • B:第二人
 1 /*============================================
 2   > Copyright (C) 2014 All rights reserved.
 3   > FileName:2.c
 4   > author:donald
 5   > date:2014/08/22/ 20:29:02
 6   > details:
 7 ==============================================*/
 8 
 9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <sys/types.h>
13 #include <sys/stat.h>
14 #include <fcntl.h>
15 #define N 1024
16 int main(int argc, const char *argv[])
17 {
18     
19     if(mkfifo(argv[2],0666) == -1 || mkfifo(argv[3],0666) == -1){
20         perror("mkfifo");
21         exit(1);
22     }
23 
24     int fd_12,fd_21,fd_23,fd_32;
25     char buf[N];
26     fd_12 = open(argv[1],O_RDONLY);
27     fd_21 = open(argv[2],O_WRONLY);
28     fd_23 = open(argv[3],O_WRONLY);
29     fd_32 = open(argv[4],O_RDONLY);
30 
31     printf("open success\n");
32 
33     if(fork() == 0){//12  r
34         close(fd_32);
35         close(fd_21);
36         close(fd_23);
37         while(memset(buf,0,N),read(fd_12,buf,N) != 0){
38             printf("from 1:");
39             write(1,buf,strlen(buf));
40         }
41         close(fd_12);
42         exit(1);
43     }
44    
45     if(fork() == 0){//32  r
46         close(fd_12);
47         close(fd_21);
48         close(fd_23);
49         while(memset(buf,0,N),read(fd_32,buf,N) != 0){
50             printf("from 3:");
51             write(1,buf,strlen(buf));
52         }
53         close(fd_32);
54         exit(1);
55     }
56 
57     //21 23  w
58     close(fd_12);
59     close(fd_32);
60     while(memset(buf,0,N),fgets(buf,N,stdin) != NULL){
61         write(fd_21,buf,strlen(buf));
62         write(fd_23,buf,strlen(buf));
63     }
64     close(fd_21);
65     close(fd_23);
66     wait(NULL);
67     wait(NULL);
68 
69     unlink(argv[2]);
70     unlink(argv[3]);
71     printf("program 2 over\n");
72     return 0;
73 }
2.c
  • C:第三人
 1 /*============================================
 2   > Copyright (C) 2014 All rights reserved.
 3   > FileName:3.c
 4   > author:donald
 5   > date:2014/08/22/ 20:29:13
 6   > details:
 7 ==============================================*/
 8 #include <stdio.h>
 9 #include <stdlib.h>
10 #include <string.h>
11 #include <sys/types.h>
12 #include <sys/stat.h>
13 #include <fcntl.h>
14 #define N 1024
15 int main(int argc, const char *argv[])
16 {
17     
18     if(mkfifo(argv[2],0666) == -1 || mkfifo(argv[4],0666) == -1){
19         perror("mkfifo");
20         exit(1);
21     }
22 
23     int fd_13,fd_31,fd_23,fd_32;
24     char buf[N];
25     fd_13 = open(argv[1],O_RDONLY);
26     fd_31 = open(argv[2],O_WRONLY);
27     fd_23 = open(argv[3],O_RDONLY);
28     fd_32 = open(argv[4],O_WRONLY);
29 
30     printf("open success\n");
31 
32     if(fork() == 0){//13  r
33         close(fd_31);
34         close(fd_23);
35         close(fd_32);
36         while(memset(buf,0,N),read(fd_13,buf,N) != 0){
37             printf("from 1:");
38             write(1,buf,strlen(buf));
39         }
40         close(fd_13);
41         exit(1);
42     }
43     if(fork() == 0){//23  r
44         close(fd_13);
45         close(fd_31);
46         close(fd_32);
47         while(memset(buf,0,N),read(fd_23,buf,N) != 0){
48             printf("from 2:");
49             write(1,buf,strlen(buf));
50         }
51         close(fd_23);
52         exit(1);
53     }
54 
55     //31 32  w
56     close(fd_13);
57     close(fd_23);
58     while(memset(buf,0,N),fgets(buf,N,stdin) != NULL){
59         write(fd_31,buf,strlen(buf));
60         write(fd_32,buf,strlen(buf));
61     }
62     close(fd_31);
63     close(fd_32);
64     wait(NULL);
65     wait(NULL);
66 
67     unlink(argv[2]);
68     unlink(argv[4]);
69     printf("program 3 over\n");
70     return 0;
71 }
3.c

 PS:在命令行参数中还需注意的,假设1.c、2.c、3.c的可执行文件为A.out、B.out、C.out。命令行参数分别为:(其实和表格里分析的一样)

            1. ./A.out   12.fifo  13.fifo  21.fifo   31.fifo
            2. ./B.out   12.fifo  21.fifo  23.fifo   32.fifo
            3. ./C.out   13.fifo  31.fifo  23.fifo   32.fifo

 

郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。