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：

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. 1. 1. 1. 1. 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