用消息队列实现进程间通讯

程序也就是这么个程序，能够实现进程间通讯，自己也是费了不少功夫想出来的，感觉设计确实是比实现复杂不少。
发到这里当个备份吧。

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <unistd.h>
 4 #include <string.h>
 5 #include <sys/ipc.h>
 6 #include <sys/msg.h>
 7 #define size 512
 8 struct msg{
 9     int sign;    int a1;        int a2;
10     char message[size];
11 }mymsg;
12 int main(){
13     int pid;
14     char name[size];
15     int id;
16     printf("please input the name:
");
17     fgets(name,size,stdin);
18     id=getpid();
19     int sid=msgget(9967,0777|IPC_CREAT);
20     mymsg.a1=id;
21     mymsg.sign=1;
22     strcpy(mymsg.message,name);
23     if(msgsnd(sid,&mymsg,size,0)==-1){
24         perror("msgsnd");
25         exit(1);
26     }
27 
28     pid=fork();
29     if(pid==0){
30         int lid=msgget(id,0777|IPC_CREAT);
31         while(1){
32             if(msgrcv(lid,&mymsg,size,0,0)==-1){
33                 perror("msgrcv");
34                 exit(1);
35             }
36             if(mymsg.sign==1){
37                 printf("%d : %s",mymsg.a1,mymsg.message);
38             }else if(mymsg.sign==2){
39                 printf("id=%d , name=%s",mymsg.a1,mymsg.message);
40             }else if(mymsg.sign==5){
41                 printf("warning : no such user online!!!!!!
");
42             }
43         }
44     }else{
45         int sid=msgget(9967,0777|IPC_CREAT);
46         int sign1;
47         while(1){
48             printf("input 2 for get the info of login.
");
49             printf("input 3 for send the message to somebody
");
50             printf("input 4 for quit
");
51             scanf("%d",&sign1);
52             if(sign1==2){
53                 mymsg.sign=2;
54                 mymsg.a1=id;
55                 if(msgsnd(sid,&mymsg,size,0)==-1){
56                     perror("msgsnd");
57                     exit(1);
58                 }
59             }else if(sign1==3){
60                 mymsg.sign=3;
61                 mymsg.a1=id;
62                 printf("please input the id you want to send to:
");
63                 scanf("%d",&mymsg.a2);
64                 getchar();
65                 printf("please input the message:
");
66                 fgets(mymsg.message,size,stdin);
67                 if(msgsnd(sid,&mymsg,size,0)==-1){
68                     perror("msgsnd");
69                     exit(1);
70                 }
71             }else if(sign1==4){
72                 mymsg.sign=4;
73                 mymsg.a1=id;
74                 printf("goodbye~
");
75                 if(msgsnd(sid,&mymsg,size,0)==-1){
76                     perror("msgsnd");
77                     exit(1);
78                 }
79                 exit(1);
80             }
81             
82         }
83     }
84     return 0;
85 }
86 
87 
88 
89 
90 
91             
92

客户端程序

  1 #include <stdio.h>
  2 #include <fcntl.h>
  3 #include <stdlib.h>
  4 #include <unistd.h>
  5 #include <string.h>
  6 #include <sys/ipc.h>
  7 #include <sys/msg.h>
  8 #include <time.h>
  9 #define size 512
 10 struct msg{
 11     int sign;    int a1;        int a2;
 12     char message[size];
 13 }mymsg;
 14 struct list{
 15     int id;
 16     char name[size];
 17     struct list *next;
 18 }mylist;
 19 void del(int del){
 20     struct list *e;
 21     struct list *opp;
 22     for(opp=&mylist;;opp=opp->next){
 23         if(opp->id==del){
 24             for(e=&mylist;e->next!=opp;e=e->next){
 25             }
 26             e->next=opp->next;
 27             free(opp);
 28             return;
 29         }
 30         if(opp->next==NULL) break;
 31     }
 32     return;
 33 
 34 }
 35 int check(int nnn){
 36     struct list *oop;
 37     for(oop=&mylist;;oop=oop->next){
 38         if(oop->id==nnn){
 39             return 1;
 40         }
 41         if(oop->next==NULL) return 0;
 42         
 43     }
 44     return 0;
 45 }
 46 int main(){
 47     int sid=msgget(9967,0777|IPC_CREAT);
 48     int lid;
 49     struct list *op;
 50     mylist.next=NULL;
 51     while(1){
 52         if(msgrcv(sid,&mymsg,size,0,0)==-1){
 53             perror("msgrcv");
 54             exit(1);
 55         }
 56         if(mymsg.sign==1){
 57             time_t tp;
 58             tp=time(&tp);
 59             FILE *fp;
 60             if((fp=fopen("./log.txt","a+w"))==NULL){
 61                 perror("open");
 62             }
 63             printf("%s",ctime(&tp));
 64 
 65             printf("log in:id=%d,name=%s",mymsg.a1,mymsg.message);
 66             fprintf(fp,"%s",ctime(&tp));
 67             fprintf(fp,"log in:id=%d,name=%s",mymsg.a1,mymsg.message);
 68             fclose(fp);
 69             struct list *p=(struct list *)malloc(sizeof(struct list));
 70             for(op=&mylist;op->next!=NULL;op=op->next);
 71             p->id=mymsg.a1;
 72             strcpy(p->name,mymsg.message);
 73             p->next=NULL;
 74             op->next=p;
 75             
 76         }else if(mymsg.sign==2){
 77             mymsg.sign=2;
 78             lid=msgget(mymsg.a1,0777|IPC_CREAT);
 79             for(op=mylist.next;;op=op->next){
 80                 strcpy(mymsg.message,op->name);
 81                 mymsg.a1=op->id;
 82                 if(msgsnd(lid,&mymsg,size,0)==-1){
 83                     perror("msgsnd");
 84                     exit(1);
 85                 }
 86                 if(op->next==NULL) break;
 87             }
 88         }else if(mymsg.sign==3){
 89             mymsg.sign=1;
 90             if(check(mymsg.a2)==0){
 91                 lid=msgget(mymsg.a1,0777|IPC_CREAT);
 92                 mymsg.sign=5;
 93                 if(msgsnd(lid,&mymsg,size,0)==-1){
 94                     perror("msgsnd");
 95                     exit(1);
 96                 }
 97                 continue;
 98             }
 99             lid=msgget(mymsg.a2,0777|IPC_CREAT);
100             if(msgsnd(lid,&mymsg,size,0)==-1){
101                 perror("msgsnd");
102                 exit(1);
103             }
104         }else if(mymsg.sign==4){
105             struct list *e;
106             del(mymsg.a1);
107         }    
108     }
109     return 0;
110 }

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