利用C实现聊天室搭建 附带客户端与服务器的代码

利用C语言实现聊天室，首先要搭建一个C/S模型

1：服务端需要拥有一个文件来存放用户名和密码；

每个用户在注册时即创建一个自己的文件，其他用户向该用户发送消息时存放在这个文件里；

2：客户端需要拥有一个系统文件和不同好友之间的聊天文件；

A通过读取服务器中的A文件，将里面的消息分别存放到A的系统消息文件和聊天文件里；

3：C/S之间传递消息利用SOCKET；

参考：http://blog.csdn.net/wjb123sw99/article/details/76898877

搭建聊天室难点有3：

1：实现客户端与服务器的通信

2：实现服务器对多个客户端的服务

3：客户端实现动态聊天；输入的文字不受屏幕上不断输出的文字的影响

首先我们先建立一个简单的1对1 C\S模型

// vi ser.c

#include<stdio.h> #include<string.h>#include<sys/types.h>#include<error.h>#include<sys/socket.h>#include<netinet/in.h>int main()                //服务器端{    int socket_fd,connect_fd;    char buff[1000]={0};    struct sockaddr_in servaddr;    socket_fd=socket(AF_INET,SOCK_STREAM,0);   //创建一个套接字    servaddr.sin_family=AF_INET;         servaddr.sin_addr.s_addr=htonl(INADDR_ANY);    servaddr.sin_port=htons(8000);    if ( bind(socket_fd,(struct sockaddr*)&servaddr,sizeof(servaddr) )==-1)   //给套接字绑定端口和协议    {       printf("bind error!\n");   //如果出错，试试等会再运行       return 0;    }    listen(socket_fd,10);       //监听套接字    connect_fd=accept(socket_fd,NULL,NULL);   //同意链接    while(1)    {        if(recv(connect_fd,buff,999,0)==0)   //接受数据               break;             //如果连接断开则停止循环        printf("get:%s",buff);  //输出接受数据的内容    }    close(connect_fd);    close(socket_fd);    return 0;}

//vi lic.c

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<errno.h>#include<sys/types.h>#include<sys/socket.h>#include<netinet/in.h>int main(int argc, char** argv)   //客户端{    if(argc!=2)           return 0;    int sockfd;    char buff[1000]={0};    struct sockaddr_in servaddr;    sockfd=socket(AF_INET,SOCK_STREAM,0);    servaddr.sin_family = AF_INET;   //iv4协议    servaddr.sin_port = htons(8000);  //8000端口    inet_pton(AF_INET, argv[1], &servaddr.sin_addr);  //指定IP地址      if( connect(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)  //链接服务器      {        printf("connect error: %s(errno: %d)\n",strerror(errno),errno);        return 0;    }    while(1)    {        printf("Enter:");              fgets(buff,998,stdin);        send(sockfd,buff,strlen(buff),0);    }

首先编译源代码
gcc ser.c -o ser

gcc lic.c -o lic

如何查看服务器IP

ifconfig

最后搭建c/s

./ser

./lic.c xxx.xxx.xxx.xxx

结果展示

在1对1基础上搭建1对多 C/S模型

注意避免僵尸进程的产生

这里我们只需修改服务器程序

多进程服务器搭建

#include<stdio.h>#include<string.h>#include<sys/types.h>#include<error.h>#include<sys/socket.h>#include<netinet/in.h>#include<signal.h>#include<sys/wait.h>void handle(){    while(waitpid(-1,NULL,WNOHANG));  //处理完当前所有的僵尸进程}int main()       //服务端{    int socket_fd,connect_fd;    char buff[1000]={0};    struct sockaddr_in servaddr;    socket_fd=socket(AF_INET,SOCK_STREAM,0);    servaddr.sin_family=AF_INET;    servaddr.sin_addr.s_addr=htonl(INADDR_ANY);    servaddr.sin_port=htons(8000);    if ( bind(socket_fd,(struct sockaddr*)&servaddr,sizeof(servaddr) )==-1)    {        printf("bind error!\n");       return 0;    }    listen(socket_fd,10);    while(1)    {        connect_fd=accept(socket_fd,NULL,NULL);        if(!fork())   //每接受一个客户端开一个子进程        {            while(1)            {                if(recv(connect_fd,buff,999,0)==0)                    return 0;                printf("get:%s",buff);            }        }        signal(SIGCHLD,handle);  //当子进程结束时，运行handle函数    }    return 0;}

多线程服务器搭建

#include<stdio.h>  #include<string.h>  #include<sys/types.h>  #include<error.h>  #include<sys/socket.h>  #include<netinet/in.h>  #include<signal.h>  #include<sys/wait.h>#include <pthread.h>void *thread(void *arg){    int connect_fd=*(int *)arg;    char buff[1000]={0};      while(1)      {          if(recv(connect_fd,buff,999,0)==0)             return ((void *)0);          printf("get:%s",buff);     } }  int main()       //服务端  {      int socket_fd,connect_fd;      struct sockaddr_in servaddr;      socket_fd=socket(AF_INET,SOCK_STREAM,0);      servaddr.sin_family=AF_INET;      servaddr.sin_addr.s_addr=htonl(INADDR_ANY);      servaddr.sin_port=htons(8000);      if ( bind(socket_fd,(struct sockaddr*)&servaddr,sizeof(servaddr) )==-1)      {          printf("bind error!\n");         return 0;      }      listen(socket_fd,10);      while(1)      {        connect_fd=accept(socket_fd,NULL,NULL);        pthread_t id;        int ret;        ret=pthread_create(&id,NULL,thread,&connect_fd); // 成功返回0，错误返回错误编号    }      return 0;  }  

在1对多的C/S模型上搭建聊天室

基础功能如下：

1：实现注册新用户和登录的功能

2：可以添加好友

3：可以和好友聊天

完善的功能：

1：查看当前好友是否在线

2：修改昵称

3：实现多人聊天（第三个功能，博主懒，没去码，感兴趣的可以去实现）

分享代码：

客户端和服务端必须在不同目录下运行！！！！！

服务端代码如下

ser.c

#include<stdio.h>  #include<stdlib.h>  #include<string.h>  #include<errno.h>  #include<sys/types.h>  #include<sys/socket.h>  #include<netinet/in.h>  #include <sys/wait.h>#include <sys/stat.h>#include <fcntl.h>typedef struct userinfo{    char id[20];    char codes[20];    char name[20];    struct userinfo *next;    int friendnum;    int state;    char friend[100][2][20];}user;user *head,*tail,nowuser,usenull;#include"ser2.h"int main(int argc, char** argv)  {      int    socket_fd, connect_fd;      struct sockaddr_in     servaddr;      char    buff[4096];      if( (socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1 )    {        printf("create socket error: %s(errno: %d)\n",strerror(errno),errno);        exit(0);      }      memset(&servaddr, 0, sizeof(servaddr));      servaddr.sin_family = AF_INET;      servaddr.sin_addr.s_addr = htonl(INADDR_ANY);      servaddr.sin_port = htons(8000);      if( bind(socket_fd, (struct sockaddr*)&servaddr, sizeof(servaddr)) == -1)    {          printf("bind socket error: %s(errno: %d)\n",strerror(errno),errno);          exit(0);      }      if( listen(socket_fd, 10) == -1)    {          printf("listen socket error: %s(errno: %d)\n",strerror(errno),errno);          exit(0);      }      printf("======waiting for client's request======\n");    //main     while(1)    {         printf("wait......\n");        if( (connect_fd = accept(socket_fd, (struct sockaddr*)NULL, NULL)) == -1)        {              printf("accept socket error: %s(errno: %d)",strerror(errno),errno);              continue;          }         printf("get a new cli\n");         while(!fork())    //a new ser to a cli        {            int n=0;            n = recv(connect_fd, buff, 4095, 0);              if(0==n)                return 0;            buff[n] = '\0';            printf("recv msg from client: %s\n", buff);            char login[]="login\n";   //login id            char sign[]="sign\n";            char quit[]="quit\n";            char change[]="change name\n";            char addfr[]="add a friend\n";            char check[]="check file\n";            char chat[]="i went to chat\n";            char renew[]="renew data\n";            char agree[]="agree friend\n";            char seefriend[]="see friend\n";            printf("%s",buff);            if(strcmp(buff,seefriend)==0)            {                char seefi[20]={0};                recv(connect_fd,seefi,20,0);                seefr(connect_fd,seefi);            }            if(strcmp(buff,agree)==0)            {                char agreeid[4096]={0};                recv(connect_fd,agreeid,20,0);                agreefriend(agreeid);                send(connect_fd,&nowuser,sizeof(user),0);            }             if(strcmp(buff,renew)==0)            {                printf("i am renew my data!!!!!!!!!!!!!!!!!!\n");    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    int idture=0;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(nowuser.id,tail->id)==0 )        {            idture++;            break;        }    }    printf("my friend number is %d\n",tail->friendnum);    nowuser=*tail;    freeuser();                printf("my firend number have %d\n",nowuser.friendnum);   //                send(connect_fd,&nowuser,sizeof(user),0);                printf("i am renew data\n");                printf("this id is %s",nowuser.id);                int ren=strlen(nowuser.id);                printf("id len is %di\n",ren);                char renewuser[20]={0};                strcpy(renewuser,nowuser.id);                printf("cmp id id %s",renewuser);                renewuser[ren-1]='\0';                FILE *fl=fopen(renewuser,"a+");                printf("i open the file %s!\n",renewuser);                int renewstate;                while(1)                {                    renewstate=0;                    printf("i will read state\n");                    fread(&renewstate,4,1,fl);                    printf("i am read state is %d\n",renewstate);                    if(renewstate==0)                    {                        send(connect_fd,"read over\n",20,0);                        printf("read over\n");                        break;                    }                    if(renewstate==1)                    {                        char success[20]={0};                        send(connect_fd,"request news\n",20,0);                        recv(connect_fd,success,20,0);                        printf("%s",success);                        printf("request news\n");                        int renewsize;                        fread(&renewstate,4,1,fl);                        printf("len %d\n",renewstate);                        char renewid[20]={0};                        fread(&renewid,20,1,fl);                        printf("read id is %s!\n",renewid);                        send(connect_fd,renewid,20,0);                    }                    if(renewstate==3)                    {                        char renewid[20]={0};                        fread(renewid,20,1,fl);                        printf("i get new form %s !",renewid);                        int renewsize;                        fread(&renewsize,4,1,fl);                        printf("renewsize=%d\n",renewsize);                        char renewbuf[4096]={0};                        fread(renewbuf,renewsize,1,fl);                        printf("new is %s",renewbuf);                        send(connect_fd,"chat news\n",20,0);                        sleep(1);                        send(connect_fd,renewid,20,0);                        sleep(1);                        send(connect_fd,&renewsize,4,0);                        sleep(1);                        send(connect_fd,renewbuf,renewsize,0);                    }                }                fclose(fl);                fl=fopen(renewuser,"w+");                fclose(fl);            }                if(strcmp(buff,chat)==0)            {                printf("user went to chat!\n");                char chatname[20]={0};                recv(connect_fd,chatname,20,0);                printf("chatid is %s",chatname);                int chatlen=strlen(chatname);                chatname[chatlen-1]='\0';                printf("file is %s!\n",chatname);                FILE *fk=fopen(chatname,"a+");                int chatstate=3;                fwrite(&chatstate,4,1,fk);                fwrite(nowuser.id,20,1,fk);                char chatbuff[4096]={0};                printf("s1\n");                recv(connect_fd,chatbuff,4095,0);                printf("s2\n");                printf("new is %s\n",chatbuff);                  int chatsize=0;                chatsize=strlen(chatbuff)+1;                                fwrite(&chatsize,4,1,fk);                fwrite(chatbuff,chatsize,1,fk);                fclose(fk);                printf("write over!\n");            }            if(strcmp(buff,check)==0)            {                int  newtype=0;                char usfile[20];                strcpy(usfile,nowuser.id);                int usfilesize=strlen(usfile);                usfile[usfilesize-1]='\0';                printf("my file name is %s heihei\n",usfile);                FILE *fj=fopen(usfile,"a+");                while(1)                {                    sleep(1);                                        newtype=0;                    fread(&newtype,4,1,fj);                    printf("i am read file state data %d\n",newtype);                    if(newtype==0)                    {                        send(connect_fd,"system news read over\n",50,0);                        fclose(fj);                        break;                    }                    if(newtype==1)                    {                        char systemnew[4096]={0};                        int  systemsize=0;                         fread(&systemsize,4,1,fj);   //requestor id size                        fread(systemnew,systemsize,1,fj); //requertor id                        int i4;   //check requertor have been now?                        int i5=0;                        for(i4=0;i4<nowuser.friendnum;i4++)                        {                            if(strcmp(nowuser.friend[i4][0],systemnew)==0)                            {                                i5++;                                break;                            }                        }                        if(i5>0)                            continue;                        send(connect_fd,"someone went to be your friend\n",50,0);                        send(connect_fd,systemnew,4096,0);                          char n4[20]={0};                        recv(connect_fd,n4,19,0);                        if(strcmp(n4,"agree\n")==0)                        {                            agreefriend(systemnew);                            printf("im new friend %s",nowuser.friend[nowuser.friendnum-1][0]);                            printf("i have %d friend\n",nowuser.friendnum);                            send(connect_fd,&nowuser,sizeof(user),0);                            printf("send success\n");                        }                                                continue;                    }                }                fj=fopen(usfile,"w+");                close(fj);            }                if(strcmp(buff,addfr)==0)            {                int n1=0;                char addid[20]={0};                recv(connect_fd,addid,19,0);                printf("what is id?id is %s   su\n",addid);                n1=addfriend(addid);                if(n1==0)                    send(connect_fd,"id not exist\n",50,0);                if(n1==1)                    send(connect_fd,"add friend request already sent\n",50,0);            }            if(strcmp(buff,change)==0)            {               int n1=0;               char newname[20]={0};               recv(connect_fd,newname,19,0);               n1=changeuser(newname);               if(n1==2)                   send(connect_fd,"name change success\n",50,0);               else                   send(connect_fd,"name change error\n",50,0);               sleep(1);                   send(connect_fd,&nowuser,sizeof(user),0);            }            if(strcmp(buff,login)==0)            {                int n1;                char newid[2][20]={0};                recv(connect_fd, newid,40,0);                n1=adduser(newid);                if(n1==0)                    send(connect_fd,"id has been registered\n",50,0);                if(n1==1)                    send(connect_fd,"id registration successful\n",50,0);                continue;            }            if(strcmp(buff,sign)==0)            {                int n2;                char newid[2][20]={0};                recv(connect_fd,newid,40,0);                n2=signset(newid);                if(n2==0)                    send(connect_fd,"id does not exist\n",50,0);                if(n2==1)                {                    send(connect_fd,"lognin successful\n",50,0);                    sleep(1);                    send(connect_fd,&nowuser,sizeof(user),0);                }                if(n2==2)                    send(connect_fd,"node is error\n",50,0);                continue;             }            if(strcmp(buff,quit)==0)            {                if(send(connect_fd, "quit success\n", 26,0) == -1)                    printf("error\n");                quituser();                close(connect_fd);                return 0;            }         }        signal(SIGCHLD,killchild);         close(connect_fd);      }      close(socket_fd);  }  

ser2.h

void killchild(){    while(waitpid(-1,NULL,WNOHANG));}void seach(){    tail=&usenull;    while(tail->next!=NULL)    {        tail=tail->next;        printf("id=%s\n",tail->id);    }}void freeuser(){    head=&usenull;    tail=head->next;    while(head->next!=NULL)    {        while(tail->next=NULL)        {            tail=tail->next;            head=head->next;        }        free(tail);        head->next=NULL;        head=&usenull;        tail=head->next;    }}int seefr(int connect_fd,char seefi[20]){    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    int idture=0;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(seefi,tail->id)==0 )        {            idture++;            break;        }    }    send(connect_fd,&(tail->state),4,0);    freeuser();    return 0;}int quituser(){    printf("i will quit\n");    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    int idture=0;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(nowuser.id,tail->id)==0 )        {            idture++;            break;        }    }    tail->state=0;    FILE *fd=fopen("./userset","w+");   //write new data    int newnumber=0;    tail=&usenull;    while(tail->next!=NULL)    {        newnumber++;        tail=tail->next;    }    printf("new user have %d\n",newnumber);    fwrite(&newnumber,4,1,fd);    tail=&usenull;    tail=tail->next;    while(tail!=NULL)    {        int newsize=sizeof(user);        fwrite(&newsize,4,1,fd);        printf("id %s have write file\n",tail->id);        printf("state is %d\n",tail->state);        fwrite(tail,newsize,1,fd);        tail=tail->next;    }    fclose(fd);    freeuser();}int renewuser(){    printf("i am renew my data!!!!!!!!!!!!!!!!!!\n");    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    int idture=0;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(nowuser.id,tail->id)==0 )        {            idture++;            break;        }    }    printf("my friend number is %d\n",tail->friendnum);    nowuser=*tail;    freeuser();    return 0;}int adduser(char a[2][20]){    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(a[0],tail->id)==0 )        {            printf("this id has been\n");            return 0;        }    }    printf("this id is  not find\n");    user *newuser=(user *)malloc(sizeof(user));   //init user    strcpy(newuser->id,a[0]);    strcpy(newuser->codes,a[1]);    strcpy(newuser->name,a[0]);    newuser->next=NULL;    newuser->friendnum=0;    newuser->state=0;    tail->next=newuser;    printf("filename is %s",a[0]);    int cao=strlen(a[0]);    a[0][cao-1]='\0';    int asd=creat(a[0],666);         //creat myself file    close(asd);    FILE *fg=fopen(a[0],"w+");    fclose(fg);    printf("creat file successs\n");     FILE *fd=fopen("./userset","w+");   //write new data    int newnumber=0;    tail=&usenull;    while(tail->next!=NULL)    {        newnumber++;        tail=tail->next;    }    printf("new user have %d\n",newnumber);    fwrite(&newnumber,4,1,fd);    tail=&usenull;    tail=tail->next;    while(tail!=NULL)    {        int newsize=sizeof(user);        fwrite(&newsize,4,1,fd);        printf("id %s have write file\n",tail->id);        fwrite(tail,newsize,1,fd);        tail=tail->next;    }    fclose(fd);    freeuser();    return 1;}int signset(char a[2][20]){    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);     tail=&usenull;    int idture=0;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(a[0],tail->id)==0 )        {            idture++;            break;        }    }    if(idture==0)    {        freeuser();        return 0;    }    if(strcmp(a[1],tail->codes)==0)    //sign success    {        tail->state=1;        nowuser=*tail;        FILE *fd=fopen("./userset","w+");   //write new data        int newnumber=0;        tail=&usenull;        while(tail->next!=NULL)        {            newnumber++;            tail=tail->next;        }        printf("new user have %d\n",newnumber);        fwrite(&newnumber,4,1,fd);        tail=&usenull;        tail=tail->next;        while(tail!=NULL)        {            int newsize=sizeof(user);            fwrite(&newsize,4,1,fd);            printf("id %s have write file\n",tail->id);            fwrite(tail,newsize,1,fd);            tail=tail->next;        }        fclose(fd);        freeuser();        return 1;    }    freeuser();    return 2;}int changeuser( char newname[20]){    FILE *fp=fopen("./userset","a+");    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(nowuser.id,tail->id)==0 )        {            printf("this id has been\n");            break;        }    }    strcpy(tail->name,newname);    nowuser=*tail;    FILE *fd=fopen("./userset","w+");    int newnumber=0;    tail=&usenull;    while(tail->next!=NULL)    {        newnumber++;        tail=tail->next;    }    printf("new user have %d\n",newnumber);    fwrite(&newnumber,4,1,fd);    tail=&usenull;    tail=tail->next;    while(tail!=NULL)    {        int newsize=sizeof(user);        fwrite(&newsize,4,1,fd);        printf("id %s have write file\n",tail->id);        fwrite(tail,newsize,1,fd);        tail=tail->next;    }    fclose(fd);    freeuser();     return 2;}int addfriend(char a[20]){    FILE *fp=fopen("./userset","a+");   //is there a judgment?    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    int addtree=0;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(a,tail->id)==0 )        {            printf("this id has been\n");            addtree++;       //judgment            break;        }    }    if(addtree==0)       return 0;     //id id not judgment    char adf[20];    strcpy(adf,tail->id);    int adfsize=strlen(adf);    adf[adfsize-1]='\0';    freeuser();    printf("open file name is %s\n",adf);    FILE *fh=fopen(adf,"a+");    int newsstate=1;    fwrite(&newsstate,4,1,fh);    int newssize=20;    fwrite(&newssize,4,1,fh);    fwrite(nowuser.id,newssize,1,fh);    fclose(fh);    return 1;}int agreefriend(char systemnew[4096]){    FILE *fp=fopen("./userset","a+");   //see you are there?    int number=0;    fread(&number,4,1,fp);    printf("user have %d\n",number);    tail=&usenull;    for(;number>0;number--)    {        int oldsize=0;        fread(&oldsize,4,1,fp);        user *olduser=(user *)malloc(oldsize);        fread(olduser,oldsize,1,fp);        printf("i am read a user,name is %s\n",olduser->id);        olduser->next=NULL;        tail->next=olduser;        tail=tail->next;    }    fclose(fp);    tail=&usenull;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(systemnew,tail->id)==0 )        {            printf("on i find he,i agree withe you be friend\n");            break;        }    }    nowuser.friendnum+=1;  //friend+1;    strcpy(nowuser.friend[nowuser.friendnum-1][0],tail->id);    strcpy(nowuser.friend[nowuser.friendnum-1][1],tail->name);    tail->friendnum+=1;    strcpy(tail->friend[tail->friendnum-1][0],nowuser.id);    strcpy(tail->friend[tail->friendnum-1][1],nowuser.name);    tail=&usenull;    while(tail->next!=NULL)    {        tail=tail->next;        if( strcmp(nowuser.id,tail->id)==0 )        {            printf("i find myself in file\n");            break;        }    }    nowuser.next=tail->next;    *tail=nowuser;    /*  i will updata to file*/    FILE *fd=fopen("./userset","w+");   //write new data    int newnumber=0;    tail=&usenull;    while(tail->next!=NULL)    {        newnumber++;        tail=tail->next;    }    printf("new user have %d\n",newnumber);    fwrite(&newnumber,4,1,fd);    tail=&usenull;    tail=tail->next;    while(tail!=NULL)    {        int newsize=sizeof(user);        fwrite(&newsize,4,1,fd);        printf("id %s have write file\n",tail->id);        fwrite(tail,newsize,1,fd);        tail=tail->next;    }    fclose(fd);    freeuser();    return 0;}

客户端代码如下

lic.c

#include<stdio.h>  #include<stdlib.h>  #include<string.h>  #include<errno.h>  #include<sys/types.h>  #include<sys/socket.h>  #include<netinet/in.h>#include <time.h>  #include<signal.h>#include<unistd.h>typedef struct userinfo{    char id[20];    char codes[20];    char name[20];    struct userinfo *next;    int friendnum;    int state;    char friend[100][2][20];}user;user myuser;int sockfd_wjb;int chat_wjb;char chatid_wjb[20]={0};int alarmstate;#include"lic.h" int main(int argc, char** argv)  {      int    sockfd, n,rec_len;      char    recvline[4096], sendline[4096];      char    buf[4095];      struct sockaddr_in servaddr;       if( argc != 2)    {          printf("usage: ./client <ipaddress>\n");          exit(0);      }      if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)    {          printf("create socket error: %s(errno: %d)\n", strerror(errno),errno);          exit(0);      }      memset(&servaddr, 0, sizeof(servaddr));      servaddr.sin_family = AF_INET;      servaddr.sin_port = htons(8000);      if( inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)    {          printf("inet_pton error for %s\n",argv[1]);          exit(0);      }      if( connect(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)    {          printf("connect error: %s(errno: %d)\n",strerror(errno),errno);          exit(0);      }     char a[2][20];    while(1)    {        int b=face1(a);        if(b==1)        {            char login[]="login\n";            char num[4096]={0};            send(sockfd,login,strlen(login),0);            send(sockfd,a,sizeof(a),0);            recv(sockfd,num,4095,0);            printf("get:%s",num);            getchar();            if(strcmp(num,"id has been registered\n")==0)                continue;            if(strcmp(num,"id registration successful\n")==0)                continue;         }         if(b==0)         {             char sign[]="sign\n";             char num[4096]={0};             send(sockfd,sign,strlen(sign),0);             send(sockfd,a,sizeof(a),0);             recv(sockfd,num,4095,0);             printf("get:%s",num);             getchar();             if( strcmp(num,"id does not exist\n")==0 )                 continue;             if( strcmp(num,"node is error\n") ==0 )                 continue;             if( strcmp(num,"lognin successful\n")==0 )                 break;                }    }    printf("1\n");    recv(sockfd,&myuser,4095,0);    printf("2\n");    creatfile();    printf("3\n");    renew(sockfd);    printf("4\n");    while(1)    {           int sele=face2();        if(sele==6)        {            while(1)            {                 printf("please enter you went chat friend id\n");                 printf("Enter:");                 char chatid[20]={0};                 fgets(chatid,20,stdin);                 int i5=0;                 int i5a=0;                 for(i5=0;i5<myuser.friendnum;i5++)                 {                      if(strcmp(chatid,myuser.friend[i5][0])==0)                      {                           i5a++;                           break;                      }                 }                 if(i5a==0)                 {                      char n6[5]={0};                      while(1)                      {                          printf("this id not your friend!\n");                          printf("1:return main inteface\n");                          printf("2:continue\n");                          printf("enter:");                          fgets(n6,3,stdin);                          if(strcmp(n6,"1\n")==0)                              break;                          if(strcmp(n6,"2\n")==0)                              break;                      }                      if(strcmp(n6,"1\n")==0)                          break;                      if(strcmp(n6,"2\n")==0)                          continue;                 }                 if(i5a!=0)                 {                     printf("shi is you friend\n");                      sockfd_wjb=sockfd;                     strcpy(chatid_wjb,chatid);                     chatroom(sockfd,chatid);                     printf("chat over!");                     getchar();                     break;                 }            }        }        if(sele==2)        {            strcpy(sendline,"quit\n");            if( send(sockfd, sendline, strlen(sendline), 0) < 0)              {                  printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);                  exit(0);              }              sleep(1);            if((rec_len = recv(sockfd, buf, 4095,0)) == -1)             {                  perror("recv error");                  exit(1);              }              buf[rec_len]  = '\0';              printf("get: %s ",buf);            char quit[]="quit success\n";            if(strcmp(buf,quit)==0)            break;        }        if(sele==1)        {            strcpy(sendline,"change name\n");            if( send(sockfd, sendline, strlen(sendline), 0) < 0)              {                  printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);                  exit(0);              }              printf("enter you went name:");            char newname[20];            fgets(newname,20,stdin);            if( send(sockfd, newname, strlen(newname), 0) < 0)              {                  printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);                  exit(0);              }              if((rec_len = recv(sockfd, buf, 4095,0)) == -1)             {                  perror("recv error");                  exit(1);              }              buf[rec_len]  = '\0';              printf("get:%s",buf);             recv(sockfd,&myuser,4095,0);            getchar();        }        if(sele==3)            seefriend(sockfd);        if(sele==4)        {            strcpy(sendline,"add a friend\n");            char addid[20]={0};            printf("please enter you went add id:");            fgets(addid,19,stdin);            int adda;            int addab=0;            for(adda;adda<myuser.friendnum;adda++)            {                if( strcmp(myuser.friend[adda][0],addid)==0 )                {                    printf("he has been you friend,not add\n");                    addab=1;                    break;                }            }            if(addab==1)                continue;            if( send(sockfd, sendline, strlen(sendline), 0) < 0)              {                  printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);                  exit(0);              }              if( send(sockfd, addid, strlen(addid), 0) < 0)              {                  printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);                  exit(0);              }              if((rec_len = recv(sockfd, buf, 4095,0)) == -1)             {                  perror("recv error");                  exit(1);              }              buf[rec_len]  = '\0';              printf("get:%s",buf);            getchar();        }         if(sele==5)        {            renew(sockfd);            char systemid[20]={0};            int systemlen=strlen(myuser.id);            strcpy(systemid,myuser.id);            systemid[systemlen-1]='\0';            FILE *fe=fopen(systemid,"a+");            while(1)            {                int systemstate;                systemstate=0;                fread(&systemstate,4,1,fe);                if(systemstate==0)                    break;                if(systemstate==1)                {                    int systemsize=0;                    char systemid[20]={0};                    fread(&systemsize,4,1,fe);                    fread(systemid,20,1,fe);                    while(1)                    {                        char agre[5]={0};                        printf("shi went quester be your frienid:%s",systemid);                        printf("agree to press 1\n");                        printf("refuse to press 2\n");                        fgets(agre,3,stdin);                        if(strcmp(agre,"1\n")==0)                        {                             send(sockfd,"agree friend\n",20,0);                            sleep(1);                            send(sockfd,systemid,20,0);                            recv(sockfd,&myuser,4096,0);                            break;                        }                        if(strcmp(agre,"2\n")==0)                            break;                    }                }            }            fclose(fe);                           fe=fopen(systemid,"w+");            fclose(fe);                       }          }} 

lic.h

int face1(char a[2][20] ){    while(1)    {        system("clear");        printf("----welcome to use SU chat room----\n");        printf("If you already have an account,press 1\n");        printf("If you do not  have an accout,press 2 to register\n");        printf("Enter(1 or 2):");        char num[5];        fgets((char *)&num,5,stdin);        if( strcmp(num,"1\n")==0)        {            printf("Please enter id:");            fgets(a[0],20,stdin);            printf("Please enter codes:");            fgets(a[1],20,stdin);            return 0;        }        if( strcmp(num,"2\n")==0 )        {            printf("Please enter id:");            fgets(a[0],20,stdin);            printf("Please enter codes:");            fgets(a[1],20,stdin);            return 1;        }     }}int face2(){    while(1)    {        char n[5]={0};        system("clear");        printf("------Hello %s\n",myuser.name);        printf("1:Change name\n");        printf("2:qiut\n");        printf("3:see friend\n");        printf("4:add frined\n");        printf("5:seach system news\n");        printf("6:chat friend\n");        printf("pleace enter number:");        fgets(n,3,stdin);        if(strcmp(n,"1\n")==0)            return 1;        if(strcmp(n,"2\n")==0)            return 2;        if(strcmp(n,"3\n")==0)            return 3;            if(strcmp(n,"4\n")==0)            return 4;            if(strcmp(n,"5\n")==0)            return 5;        if(strcmp(n,"6\n")==0)            return 6;    }}    void creatfile(){     char myname[20]={0};     strcpy(myname,myuser.id);     int n=strlen(myname);     myname[n-1]='\0';     FILE *fd=fopen(myname,"a+");     fclose(fd);     int n1;     for(n1=0;n1<myuser.friendnum;n1++)     {         char friendname[40]={0};         strcpy(friendname,myuser.friend[n1][0]);         n=strlen(friendname);         friendname[n-1]='\0';         printf("%s,,,,,%s\n",friendname,myname);         strcat(friendname,myname);         fd=fopen(friendname,"a+");         fclose(fd);     }     printf("over\n");}int renew(int sockfd){    send(sockfd,"renew data\n",20,0);    recv(sockfd,&myuser,sizeof(user),0);    while(1)    {        char renewstate[40]={0};        recv(sockfd,renewstate,20,0);        send(sockfd,"send success\n",20,0);        if(strcmp(renewstate,"read over\n")==0)            return 0;        if(strcmp(renewstate,"request news\n")==0)        {            int n7=1;            char renewid[20]={0};            recv(sockfd,renewid,20,0);            int renewsize=0;            renewsize=strlen(myuser.id);            char renewsys[20]={0};            strcpy(renewsys,myuser.id);            renewsys[renewsize-1]='\0';            FILE *fq=fopen(renewsys,"a+");            fwrite(&n7,4,1,fq);            n7=20;            fwrite(&n7,4,1,fq);            fwrite(renewid,20,1,fq);            fclose(fq);        }        if(strcmp(renewstate,"chat news\n")==0)        {            int renewsize;            char renewid[20]={0};            int renewbuff[4096]={0};            recv(sockfd,renewid,20,0);            recv(sockfd,&renewsize,4,0);            recv(sockfd,renewbuff,renewsize,0);            char renewfile[40]={0};            strcpy(renewfile,renewid);            int n9=strlen(renewfile);            renewfile[n9-1]='\0';            strcat(renewfile,myuser.id);            n9=strlen(renewfile);            renewfile[n9-1]='\0';            FILE *fw=fopen(renewfile,"a+");            fwrite(renewid,20,1,fw);            fwrite(&renewsize,4,1,fw);            fwrite(renewbuff,renewsize,1,fw);            fclose(fw);        }    }       getchar(); }void clearroom(){    int i=0;    printf("\033[0m\033[1;1H");    for(i=0;i<25;i++)    {      printf("\033[0m\033[K");      printf("\n");    }    printf("kkk12adsasdfq3r12adkfaefawrawreakwr\n");}void chatnew(){    if(alarmstate!=1)    {        printf("\n");    }    else if(chat_wjb==1)    {        alarm(3);    }    else    {    printf("\033[0m\033[s");    printf("\033[0m\033[1;1H");    char chatid[20]={0};    int sockfd=sockfd_wjb;    strcpy(chatid,chatid_wjb);    renew(sockfd);    int i=0;    printf("\033[0m\033[1;1H");    for(i=0;i<25;i++)    {      printf("\033[0m\033[K");      printf("\n");    }    printf("\033[0m\033[1;1H");    printf("------chat room--------\n");    char chatnewid[20]={0};    strcpy(chatnewid,chatid);    chatnewid[strlen(chatnewid)-1]='\0';    strcat(chatnewid,myuser.id);    chatnewid[strlen(chatnewid)-1]='\0';    int newnum=0;    FILE *fr=fopen(chatnewid,"a+");    while(1)    {        int n8;        char systemid[20]={0};        n8=0;        n8=fread(systemid,20,1,fr);        if(n8==0)            break;        char chatbuff[4096]={0};        fread(&n8,4,1,fr);        fread(chatbuff,n8,1,fr);        newnum++;    }    fclose(fr);    fr=fopen(chatnewid,"a+");    while(1)    {        int n8;        char systemid[20]={0};        n8=0;        n8=fread(systemid,20,1,fr);        if(n8==0)            break;        char chatbuff[4096]={0};        fread(&n8,4,1,fr);        fread(chatbuff,n8,1,fr);        if(newnum>7)        {             newnum--;             continue;        }        if(strcmp(systemid,chatid)==0)            printf("friend:%s\n",chatbuff);        else            printf("me:%s\n",chatbuff);     }     fclose(fr);     printf("\033[0m\033[u");     fflush(stdout);     if(alarmstate==1)         alarm(2);     }}int chatroom(int sockfd,char chatid[20]){    alarmstate=1;    chat_wjb=0;    char buff[4096]={0};    system("clear");    alarm(2);    signal(SIGALRM,chatnew);    while(1)    {        printf("\033[0m\033[30;1H");        printf("\n-------chat %s",chatid);        char chat[20]="i went to chat\n";        sleep(1);        printf("Enter news:");        fgets(buff,4095,stdin);  //buff        chat_wjb=1;        send(sockfd,chat,20,0);          sleep(1);        send(sockfd,chatid,20,0);        time_t timep;          time(&timep);        char sendname[4095]={0};        strcpy(sendname,myuser.id);        send(sockfd,chat,strlen(chat),0);        sendname[strlen(sendname)-1]=':';        buff[strlen(buff)-1]='\0';        strcat(sendname,buff);        strcpy(buff,sendname);           char timesend[]={"     send time:"};        strcat(buff,timesend);        strcat(buff,ctime(&timep));        send(sockfd,buff,strlen(buff),0);         chat_wjb=0;        char chatnewid[20]={0};         strcpy(chatnewid,chatid);        chatnewid[strlen(chatnewid)-1]='\0';        strcat(chatnewid,myuser.id);        chatnewid[strlen(chatnewid)-1]='\0';        FILE *fr=fopen(chatnewid,"a+");        fwrite(myuser.id,20,1,fr);        int sizebuff=strlen(buff);;        fwrite(&sizebuff,4,1,fr);        fwrite(buff,sizebuff,1,fr);        fclose(fr);        while(1)        {            printf("1:quit\n");            printf("2:continue chat\n");            printf("Enter:");            char chatstate[5]={0};            fgets(chatstate,3,stdin);            if(strcmp(chatstate,"1\n")==0)            {                alarmstate=0;                return 0;            }            if(strcmp(chatstate,"2\n")==0)                break;        }        system("clear");    }    return 0;} void seefriend(int sockfd){    int i;    renew(sockfd);    printf("-------your friend link--------\n");    for(i=0;i<myuser.friendnum;i++)    {        printf("id %s\n",myuser.friend[i][0]);        printf("name %s\n",myuser.friend[i][1]);        int state;        send(sockfd,"see friend\n",20,0);        sleep(1);        send(sockfd,myuser.friend[i][0],20,0);        recv(sockfd,&state,4,0);        if(state==0)            printf("off line\n");        if(state==1)            printf("on line\n");        printf("------------------------\n");    }    getchar();}

结果展示：

登录窗口

菜单窗口

聊天窗口