使用消息队列实现简单聊天程序

beyes

两个聊天端，分别称之为 server和 client .

server 端代码：

#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/stat.h>
#include <string.h>

#define    BUF_SIZE    256
#define PROJ_ID        32
#define PATH_NAME    "/tmp"
#define    SERVER_MSG    1
#define    CLIENT_MSG    2

int main()
{
    struct mymsgbuf {
        long msgtype;
        char ctrlstring [BUF_SIZE];
    } msgbuffer;

    int    qid;
    int    msglen;
    int    msgkey;
   
    if ((msgkey = ftok (PATH_NAME, PROJ_ID)) == -1) {
        perror ("ftok error!\n");
        exit (1);
    }

    if ((qid = msgget (msgkey, IPC_CREAT|0660)) == -1) {
        perror ("msgget error!\n");
        exit (1);
    }
   
    while (1) {
        printf ("server: ");
        fgets (msgbuffer.ctrlstring, BUF_SIZE, stdin);
        if (strncmp ("exit", msgbuffer.ctrlstring, 4) == 0) {
            msgctl (qid, IPC_RMID, NULL);
            break;
        }

        msgbuffer.ctrlstring [strlen (msgbuffer.ctrlstring) - 1] = '\0';
        msgbuffer.msgtype = SERVER_MSG;
        if (msgsnd (qid, &msgbuffer, strlen (msgbuffer.ctrlstring) + 1, 0) == -1){    /*+1为包括'\0'进去*/
            perror ("Server msgsnd error!\n");
            exit (1);
        }

        if (msgrcv (qid, &msgbuffer, BUF_SIZE, CLIENT_MSG, 0) == -1) {
            perror ("Server msgrcv error!\n");
            exit (1);
        }

        printf ("Client: %s\n", msgbuffer.ctrlstring);
    }

    exit (0);
}

client 端代码：

#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/stat.h>
#include <string.h>


#define    BUF_SIZE     256
#define PROJ_ID        32
#define PATH_NAME    "/tmp"
#define    SERVER_MSG    1
#define    CLIENT_MSG    2

int main()
{
    struct mymsgbuf {
        long msgtype;
        char ctrlstring [BUF_SIZE];
    } msgbuffer;
   
    int    qid;
    int    msglen;
    key_t    msgkey;

    if ((msgkey = ftok (PATH_NAME, PROJ_ID)) == -1) {
        perror ("ftok error!\n");
        exit (1);
    }

    if ((qid = msgget (msgkey, IPC_CREAT|0660)) == -1) {
        perror ("msgget error!\n");
        exit (1);
    }

    while (1) {
        if (msgrcv (qid, &msgbuffer, BUF_SIZE, SERVER_MSG, 0) == -1) {
            perror ("Server msgrcv error!\n");
            exit (1);
        }

        printf ("server: %s\n", msgbuffer.ctrlstring);
        printf ("client: ");
       
        fgets (msgbuffer.ctrlstring, BUF_SIZE, stdin);
        if (strncmp ("exit", msgbuffer.ctrlstring, 4) == 0) {
            break;
        }

        msgbuffer.ctrlstring [strlen (msgbuffer.ctrlstring) - 1] = '\0';
        msgbuffer.msgtype = CLIENT_MSG;
   
        if (msgsnd (qid, &msgbuffer, strlen (msgbuffer.ctrlstring) + 1, 0) == -1) {
            perror ("client msgsnd error!\n");
            exit (1);
        }
    }

    exit (0);
}

server 运行及输出：

beyes@linux-beyes:~/C/queue> ./server.exe
server: hello sam
Client: hello tom
server: what are you doing now ?
Client: yes ,i am working, very busy!!
server: so do i, i will exit now
Client: ok bye
server: exit

client 运行及输出：

beyes@linux-beyes:~/C/queue> ./client.exe
server: hello sam
client: hello tom
server: what are you doing now ?
client: yes ,i am working, very busy!!
server: so do i, i will exit now
client: ok bye
Server msgrcv error!
: Identifier removed