明明定义了结构体，为什么还是报错

Question

typedef struct CLIENT{ int fd; char *name; struct sockaddr_in addr; char *data; }; void process_cli(CLIENT *client,char *recvbuf,int len); void savedata(char *recvbuf,int len,char *data); main(){ int i,maxi,maxfd,sockfd; int nready; ssize_t n; fd_setrset,allset; int listenfd,connectfd; struct sockaddr_in server; CLIENT client[FD_SETSIZE]; char recvbuf[MAXDATASIZE];编译的时候提示：c:22:1: warning: useless storage class specifier in empty declaration }; ^iotcpserver.c:23:18: error: unknown type name ‘CLIENT’ void process_cli(CLIENT *client,char *recvbuf,int len);                  ^iotcpserver.c:26:1: warning: return type defaults to ‘int’ [-Wimplicit-int] main(){ ^iotcpserver.c: In function ‘main’:iotcpserver.c:30:2: error: ‘fd_setrset’ undeclared (first use in this function)  fd_setrset,allset;  ^iotcpserver.c:30:2: note: each undeclared identifier is reported only once for each function it appears iniotcpserver.c:30:13: error: ‘allset’ undeclared (first use in this function)  fd_setrset,allset;             ^iotcpserver.c:33:2: error: unknown type name ‘CLIENT’  CLIENT client[FD_SETSIZE];  ^iotcpserver.c:60:12: error: request for member ‘fd’ in something not a structure or union   client[i].fd=-1;            ^iotcpserver.c:67:3: error: ‘rset’ undeclared (first use in this function)   rset=allset;   ^iotcpserver.c:76:17: error: request for member ‘fd’ in something not a structure or union     if(client[i].fd<0){                 ^iotcpserver.c:77:15: error: request for member ‘fd’ in something not a structure or union      client[i].fd=connectfd;               ^iotcpserver.c:78:15: error: request for member ‘name’ in something not a structure or union      client[i].name=new char[MAXDATASIZE];               ^iotcpserver.c:78:21: error: ‘new’ undeclared (first use in this function)      client[i].name=new char[MAXDATASIZE];                     ^iotcpserver.c:78:25: error: expected ‘;’ before ‘char’      client[i].name=new char[MAXDATASIZE];                         ^iotcpserver.c:79:15: error: request for member ‘addr’ in something not a structure or union      client[i].addr=addr;               ^iotcpserver.c:80:15: error: request for member ‘data’ in something not a structure or union      client[i].data=new char[MAXDATASIZE];               ^iotcpserver.c:80:25: error: expected ‘;’ before ‘char’      client[i].data=new char[MAXDATASIZE];                         ^怎么解决啊？

Answer 1

#include <stdio.h>
#include <strings.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <stdlib.h>
 
#include <string.h>
 
#define PORT 1234
#define BACKLOG 5
#define MAXDATASIZE 1000
 
typedef struct CLIENT{
    int fd;
    char *name;
    struct sockaddr_in addr;
    char *data;
};
void process_cli(CLIENT *client,char *recvbuf,int len);
void savedata(char *recvbuf,int len,char *data);
 
int main(){
    int i,maxi,maxfd,sockfd;
        CLIENT client[FD_SETSIZE];
    int nready;
    ssize_t n;
    fd_setrset,allset;
    int listenfd,connectfd;
    struct sockaddr_in server;
    char recvbuf[MAXDATASIZE];
    int sin_size;
       
    if((listenfd=socket(AF_INET,SOCK_STREAM,0))==-1){
        perror("Creating socket falied.");
        exit(1);
    }
    int opt=SO_REUSEADDR;
    setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt));
     
    bzero(&server,sizeof(server));
    server.sin_family=AF_INET;
    server.sin_port=htons(PORT);
    server.sin_addr.s_addr=htonl(INADDR_ANY);
    if(bind(listenfd,(struct sockaddr *)&server,sizeof(struct sockaddr))==1){
        perror("Bind error.");
        exit(1);
    }
    if(listen(listenfd,BACKLOG)==-1){
        perror("listen() error.\n");
        exit(1);
    }
    sin_size=sizeof(struct sockaddr_in);
    maxfd=listenfd;
    maxi=-1;
    for(i=0;i<FD_SETSIZE;i++){
        client[i].fd=-1;
    }
    FD_ZERO(&allset);
    FD_SET(listenfd,&allset);
 
    while(1){
        struct sockaddr_in addr;
        rset=allset;
        nready=select(maxfd+1,&rset,NULL,NULL,NULL);
 
        if(FD_ISSET(listenfd,&rset)){
            if((connectfd=accept(listenfd,(struct sockaddr *)&addr,&sin_size))==-1){
                perror("accept() error\n");
                continue;
            }
            for(i=0;i<FD_SETSIZE;i++)
                if(client[i].fd<0){
                    client[i].fd=connectfd;
                    client[i].name=new char[MAXDATASIZE];
                                        //client[i].name=(char *)malloc(MAXDATASIZE);
                                        //stu[i].name=(char *)malloc(MAXDATASIZE);
                    client[i].addr=addr;
                    client[i].data=new char[MAXDATASIZE];
                                        //stu[i].snum=(char *)malloc(MAXDATASIZE);
                    client[i].name[0]='\0';
                    client[i].data[0]='\0';
                                        //stu[i].name[0]='\0';
                                        //stu[i].snum[0]='\0';
                    printf("You got a connection from %s.",inet_ntoa(client[i].addr.sin_addr));
                    break;
                }
                if(i==FD_SETSIZE)
                    printf("too many clients\n");
                FD_SET(connectfd,&allset);
                if(connectfd>maxfd)
                    maxfd=connectfd;
                if(i>maxi)
                    maxi=i;
                if(--nready<=0)
                    continue;
        }
        for(i=0;i<=maxi;i++){
            if((sockfd=client[i].fd)<0))
                continue;
            if(FD_ISSET(sockfd,&rset)){
                if((n=recv(sockfd,recvbuf,MAXDATASIZE,0))==0){
                    close(sockfd);
                    printf("Client(%s) closed connection.User's data:%s\n",client[i].name,client[i].data);
                    FD_CLR(sockfd,&allset);
                    client[i].fd=-1;
                                       // free(stu[i].name);
                                        //free(stu[i].data);
                    free(client[i].name);
                    free(client[i].data);
                }else
                    process_cli(&client[i],recvbuf,n);
                if(--nready<=0)
                    break;
                }
            }
        }
        close(listenfd);
}
 
void process_cli(CLIENT *client,char *recvbuf,int len){
    char sendbuf[MAXDATASIZE];
    recvbuf[len-1]='\0';
    if(strlen(client->name)==0){
        memcpy(client->name,recvbuf,len);
        printf("Client's name is:%s.\n",client->name);
        return;
    }
    printf("Received client(%s) message:%s\n",client->name,recvbuf);
    savedata(recvbuf,len,client->data);
    for(int i1=0;i1<len-1;i1++){
        sendbuf[i1]=recvbuf[len-i1-2];
    }
    sendbuf[len-1]='\0';
    send(client->fd,sendbuf,strlen(sendbuf),0);
}
 
void savedata(char *recvbuf,int len,char *data){
    int start=strlen(data);
    for(int i=0;i<len;i++){
        data[start+i]=recvbuf[i];
    }
}

Answer 2

typedef struct CLIENT{
    int fd;
    char *name;
    struct sockaddr_in addr;
    char *data;
};

你这里要将struct CLIENT结构体类型自定义成什么类型也没有指定， CLIENT client[FD_SETSIZE];这里也没有指定为struct  CLIENT client[FD_SETSIZE];

Answer 3

我用VS2008 编译的，没有出现你说的问题，是其他报错；修改后：

#include <winsock2.h>

#pragma comment (lib,"ws2_32.lib")

#define MAXDATASIZE 1024

typedef struct CLIENT{

int fd;

char *name;

struct sockaddr_in addr;

char *data;

};

void process_cli(CLIENT *client,char *recvbuf,int len);

void savedata(char *recvbuf,int len,char *data);

int main(){

int i,maxi,maxfd,sockfd;

int nready;

//ssize_t n;

//fd_setrset,allset;

int listenfd,connectfd;

struct sockaddr_in server;

CLIENT client[FD_SETSIZE];

char recvbuf[MAXDATASIZE];

}

Answer 4

如果这是 C 代码，那么你并没有把 struct CLIENT 定义为类型，typedef 的用法没写对。

14 行那里 fd_setrset,allset 缺少类型。

还有，看后面的报错，你写了 new char[MAXDATASIZE]; 这样的代码！？  你确定你写的是 C？？