关于 c:Server 无法接受来自多个客户端的消息？

Server is not able to accept() messages from multiple clients?

两个客户端能够连接到服务器，但它只接受和显示第一个客户端的输入流消息，而不是第二个客户端，尽管另一个客户端也已连接。

以下是我接受流的代码，我尝试关闭每个领带的套接字，但没有成功。

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int main(int argc,char *argv[])
{
fd_set ready;
struct sockaddr_in msgfrom;
int msgsize;
union {
uint32_t addr;
char bytes[4];
} fromaddr;

if ((progname = rindex(argv[0], ‘/’)) == NULL)
progname = argv[0];
else
progname++;
while ((ch = getopt(argc, argv,“adsp:h:”)) != –1)
switch(ch) {
case ‘a’:
aflg++; /* print address in output */
break;
case ‘d’:
soctype = SOCK_DGRAM;
break;
case ‘s’:
server = 1;
break;
case ‘p’:
port = optarg;
break;
case ‘h’:
host = optarg;
break;
case ‘?’:
default:
usage();
}
argc -= optind;
if (argc != 0)
usage();
if (!server && (host == NULL || port == NULL))
usage();
if (server && host != NULL)
usage();
/*
* Create socket on local host.
*/
if ((s = socket(AF_INET, soctype, 0)) < 0) {
perror(“socket”);
exit(1);
}
sock = setup_server();
while (!done) {
FD_ZERO(&ready);
FD_SET(sock, &ready);
FD_SET(fileno(stdin), &ready);
if (select((sock + 1), &ready, 0, 0, 0) < 0) {
perror(“select”);
exit(1);
}
if (FD_ISSET(fileno(stdin), &ready)) {
if ((bytes = read(fileno(stdin), buf, BUF_LEN)) <= 0)
done++;
send(sock, buf, bytes, 0);
}
msgsize = sizeof(msgfrom);
if (FD_ISSET(sock, &ready)) {
if ((bytes = recvfrom(sock, buf, BUF_LEN, 0, (struct sockaddr *)&msgfrom, &msgsize)) <= 0) {
done++;
} else if (aflg) {
fromaddr.addr = ntohl(msgfrom.sin_addr.s_addr);
fprintf(stderr,“%d.%d.%d.%d:”, 0xff & (unsigned int)fromaddr.bytes[0],
0xff & (unsigned int)fromaddr.bytes[1],
0xff & (unsigned int)fromaddr.bytes[2],
0xff & (unsigned int)fromaddr.bytes[3]);
}
write(fileno(stdout), buf, bytes);
}
}

这是我设置服务器的代码，供参考：

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int setup_server() {
struct sockaddr_in serv, remote;
struct servent *se;
int newsock, len;

len = sizeof(remote);
memset((void *)&serv, 0, sizeof(serv));
serv.sin_family = AF_INET;
if (port == NULL)
serv.sin_port = htons(9990);
else if (isdigit(*port))
serv.sin_port = htons(atoi(port));
if (bind(s, (struct sockaddr *)&serv, sizeof(serv)) < 0) {
perror(“bind”);
exit(1);
}
if (getsockname(s, (struct sockaddr *) &remote, &len) < 0) {
perror(“getsockname”);
exit(1);
}
fprintf(stderr,“Port number is %d\
“, ntohs(remote.sin_port));
listen(s, 1);
newsock = s;
if (soctype == SOCK_STREAM) {
fprintf(stderr,“Entering accept() waiting for connection.\
“);
newsock = accept(s, (struct sockaddr *) &remote, &len);
}
return(newsock);
}

客户端代码：

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sock = setup_client();
/*
* Set up select(2) on both socket and terminal, anything that comes
* in on socket goes to terminal, anything that gets typed on terminal
* goes out socket…
*/
while (!done) {
FD_ZERO(&ready);
FD_SET(sock, &ready);
FD_SET(fileno(stdin), &ready);
if (select((sock + 1), &ready, 0, 0, 0) < 0) {
perror(“select”);
exit(1);
}
if (FD_ISSET(fileno(stdin), &ready)) {
if ((bytes = read(fileno(stdin), buf, BUF_LEN)) <= 0)
done++;
send(sock, buf, bytes, 0);
}
msgsize = sizeof(msgfrom);
if (FD_ISSET(sock, &ready)) {
if ((bytes = recvfrom(sock, buf, BUF_LEN, 0, (struct sockaddr *)&msgfrom, &msgsize)) <= 0) {
done++;
} else if (aflg) {
fromaddr.addr = ntohl(msgfrom.sin_addr.s_addr);
fprintf(stderr,“%d.%d.%d.%d:”, 0xff & (unsigned int)fromaddr.bytes[0], 0xff & (unsigned int)fromaddr.bytes[1],
0xff & (unsigned int)fromaddr.bytes[2],
0xff & (unsigned int)fromaddr.bytes[3]);
}
write(fileno(stdout), buf, bytes);
}
//close(sock);
}
return(0);
}

/*
* setup_client() – set up socket for the mode of soc running as a
* client connecting to a port on a remote machine.
*/

int setup_client() {

struct hostent *hp, *gethostbyname();
struct sockaddr_in serv;
struct servent *se;

/*
* Look up name of remote machine, getting its address.
*/
if ((hp = gethostbyname(host)) == NULL) {
fprintf(stderr,“%s: %s unknown host\
“, progname, host);
exit(1);
}
/*
* Set up the information needed for the socket to be bound to a socket on
* a remote host. Needs address family to use, the address of the remote
* host (obtained above), and the port on the remote host to connect to.
*/
serv.sin_family = AF_INET;
memcpy(&serv.sin_addr, hp->h_addr, hp->h_length);
if (isdigit(*port))
serv.sin_port = htons(atoi(port));
else {
if ((se = getservbyname(port, (char *)NULL)) < (struct servent *) 0) {
perror(port);
exit(1);
}
serv.sin_port = se->s_port;
}
/*
* Try to connect the sockets…
*/
if (connect(s, (struct sockaddr *) &serv, sizeof(serv)) < 0) {
perror(“connect”);
exit(1);
} else
fprintf(stderr,“Connected…\
“);
return(s);
}

Server is not able to accept() messages from multiple clients?

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