我目前有一個問題在服務器和客戶端之間傳遞消息。 據我所知,我正確遵循了Beej's Socket Programming Tutorial概述的套接字編程的最佳實踐。C++套接字recv()系統調用返回-1
當我運行這兩個進程時,recv()系統調用返回-1(錯誤),而不是接收的字節數。當試圖輸出buf時,還有一堆gobbledygook角色。這是有道理的,因爲錯誤。
我想知道是否有人可以引導我在正確的方向,爲什麼我有問題與recv()?以下是相關的代碼片段。
服務器:
struct sockaddr_storage their_addr;
socklen_t addr_size;
int sockfd, newfd, byte_count, status;
char buf[512];
struct addrinfo hints, *res;
// first, load up address structs with getaddrinfo():
memset(&hints, 0, sizeof hints);
hints.ai_family = PF_INET;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
// get address info, print stuff if error
if((status = getaddrinfo("nunki.usc.edu", "21957", &hints, &res)) !=0){
fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(status));
exit(1);
}
// make a socket:
if((sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1){
cout << "socket fail" << endl;
}
// bind the socket to the port
bind(sockfd, res->ai_addr, res->ai_addrlen);
// required output
cout << "Phase1: Login server has TCP port number " << "21957 "
<< "and IP address " << getIPfromHost("nunki.usc.edu") << endl;
// listen for incoming connections
listen(sockfd, 10);
cout << "after listen" << endl;
// halt until receipt
addr_size = sizeof(their_addr);
newfd = accept(sockfd, (struct sockaddr *)&their_addr, &addr_size);
cout << "after accept" << endl;
// Now that we're connected, we can receive some data
byte_count = recv(sockfd, buf, sizeof buf, 0);
printf("recv()'d %d bytes of data in buf\n", byte_count);
printf("Msg is %s\n", buf);
客戶:
struct addrinfo hints, *res;
int sockfd;
// first, load up address structs with getaddrinfo():
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
getaddrinfo("nunki.usc.edu", "21957", &hints, &res);
// make a socket:
if((sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1){
cout << "socket fail" << endl;
}
// attempt connection to port
if(connect(sockfd, res->ai_addr, res->ai_addrlen) == -1){
cout << "connect fail" << endl;
}
// send message to server
cout << "sockfd " << sockfd << endl;
int byte_count = send(sockfd, "Hello", 5, 0);
cout << byte_count << endl;
以下是服務器輸出:
Phase1: Login server has TCP port number 21957 and IP address 68.181.201.3
after listen
after accept
recv()'d -1 bytes of data in buf
Msg is ÿhÿ?sÈ
Glæ
以下是客戶機的輸出:
sockfd 4
5
非常感謝。我對這個疏忽感到驚訝。另外,我將添加返回狀態和錯誤輸出。我承認有點懶。 – aaronmar
+1對_you不檢查退貨狀態_ – ninjalj