在 DEV-C++ 中要使用 Windows Socket Programming 必須要連結 Winsock 函式庫。連結函示庫的方法說明如下：
Step 1. 開啟工具列中的「專案」> 「專案選項」
Step 2. 在「專案選項」視窗中選擇「參數」頁面
Step 3. 按下「參數」頁面中的「新增函式庫或 Obj 檔」
Step 4. 選擇 [DEV-C++安裝目錄]\lib\libwsock32.a並按下「開啟」
Step 5. 如果在「連結器」文字框中會出現 ..\lib\libwsock32.a，則按下「確定」
完成以上步驟後就可以開始撰寫 Windows Socket 程式。
簡單的 server 程式
#include<winsock2.h>
#include<stdio.h>
int main() {
SOCKET server_sockfd, client_sockfd;
int server_len, client_len;
struct sockaddr_in server_address;
struct sockaddr_in client_address;
// 註冊 Winsock DLL
WSADATA wsadata;
if(WSAStartup(0x101,(LPWSADATA)&wsadata) != 0) {
printf("Winsock Error\n");
exit(1);
}
// 產生 server socket
server_sockfd = socket(AF_INET, SOCK_STREAM, 0); // AF_INET(使用IPv4); SOCK_STREAM; 0(使用預設通訊協定，即TCP)
if(server_sockfd == SOCKET_ERROR) {
printf("Socket Error\n");
exit(1);
}
// struct sockaddr_in {
// short int sin_family; /* AF_INT(使用IPv4) */
// unsigned short int sin_port; /* Port(埠號) */
// struct in_addr sin_addr; /* IP位址 */
// };
// sturct in_addr {
// unsigned long int s_addr;
// };
server_address.sin_family = AF_INET; // AF_INT(使用IPv4)
server_address.sin_addr.s_addr = inet_addr("127.0.0.1"); // 設定IP位址
server_address.sin_port = 9734; //設定埠號
server_len = sizeof(server_address);
if(bind(server_sockfd, (struct sockaddr *)&server_address, server_len) < 0) {
printf("Bind Error\n");
exit(1);
}
if(listen(server_sockfd, 5) < 0) {
printf("Listen Error\n");
exit(1);
}
while(1) {
char ch;
printf("Server waiting...\n");
client_len = sizeof(client_address);
client_sockfd = accept(server_sockfd, (struct sockaddr *)&client_address, &client_len);
if(client_sockfd == SOCKET_ERROR) {
printf("Accept Error\n");
exit(1);
}
recv(client_sockfd, &ch, 1, 0); // Linux socket programming 為 read
ch++;
send(client_sockfd, &ch, 1, 0); // Linux socket programming 為 write
closesocket(client_sockfd); // Linux socket programming 為 close
}
}
簡單的 client 程式
#include<winsock2.h>
#include<stdio.h>
int main() {
SOCKET sockfd;
int len;
struct sockaddr_in address;
int result;
char ch = 'A';
WSADATA wsadata;
if(WSAStartup(0x101,(LPWSADATA)&wsadata) != 0) {
printf("Winsock Error\n");
exit(1);
}
sockfd = socket(AF_INET, SOCK_STREAM, 0);
address.sin_family = AF_INET;
address.sin_addr.s_addr = inet_addr("127.0.0.1");
address.sin_port = 9734;
len = sizeof(address);
result = connect(sockfd, (struct sockaddr *)&address, len);
if(result == -1) {
printf("Connetc Error");
exit(1);
}
send(sockfd, &ch, 1, 0);
recv(sockfd, &ch, 1, 0);
printf("char from server = %c\n", ch);
closesocket(sockfd);
exit(0);
}