تفاوت‌ها

تفاوت دو نسخهٔ متفاوت از صفحه را مشاهده می‌کنید.

--- socket-programming:sendto [2024/06/18 00:30] – ایجاد شد pejman
+++ socket-programming:sendto [2024/06/18 01:02] (فعلی) – حذف شد pejman
@@ خط 1: / خط 1: @@
-====== تابع ()sendto ======
-این تابع برای نوشتن در سوکت های SOCK_DGRAM استفاده می شود.
-<code C>
-#include <sys/types.h>
-#include <sys/socket.h>
-ssize_t sendto(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen);
-</code>
-مثال echo کلاینت
-<code C>
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netdb.h>
-#define PORT "3435"
-#define SERVER "127.0.0.1"
-int main()
-{
-	char buf[BUFSIZ] = "Hello world";
-	int status, sockfd;
-	struct addrinfo hints, *res, *rp;
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_INET;
-	hints.ai_socktype = SOCK_DGRAM;
-	hints.ai_protocol = 0;
-	status = getaddrinfo(SERVER, PORT, &hints, &res);
-	if (status != 0) {
-		fprintf(stderr, "getaddrinfo() error: %s",
-			gai_strerror(status));
-		exit(EXIT_FAILURE);
-	}
-	for (rp = res; rp != NULL; rp = rp->ai_next) {
-		sockfd = socket(rp->ai_family, rp->ai_socktype,
-				rp->ai_protocol);
-		if (sockfd == -1) {
-			perror("socket() error ");
-			continue;
-		}
-		break;
-	}
-        freeaddrinfo(res);
-	if (rp == NULL) {
-		fprintf(stderr, "Could not connect()\n");
-		exit(EXIT_FAILURE);
-	}
-	status = sendto(sockfd, buf, strlen(buf), 0, rp->ai_addr,
-			rp->ai_addrlen);
-	if (status == -1) {
-		perror("sendto() error ");
-		exit(EXIT_FAILURE);
-	}
-	printf("Sent %d bytes to server\n", status);
-	ssize_t readlen;
-	readlen = recvfrom(sockfd, buf, BUFSIZ, 0, NULL, NULL);
-	if (readlen == -1) {
-		perror("recvfrom() error");
-		exit(EXIT_FAILURE);
-	}
-	printf("---\n%s\n---\n", buf);
-	printf("Receive %d bytes from server\n", status);
-	close(sockfd);
-	return 0;
-}
-</code>
-مثال echo سرور
-<code C>
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netdb.h>
-#include <arpa/inet.h>
-#define PORT "3435"
-int main()
-{
-	int status, sockfd;
-	struct addrinfo hints, *res, *rp;
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_flags = AI_PASSIVE;
-	hints.ai_family = AF_INET;
-	hints.ai_socktype = SOCK_DGRAM;
-	hints.ai_protocol = 0;
-	status = getaddrinfo(NULL, PORT, &hints, &res);
-	if (status != 0) {
-		fprintf(stderr, "getaddrinfo() error: %s\n",
-			gai_strerror(status));
-		exit(EXIT_FAILURE);
-	}
-	for (rp = res; rp != NULL; rp = rp->ai_next) {
-		sockfd = socket(rp->ai_family, rp->ai_socktype,
-				rp->ai_protocol);
-		if (sockfd == -1) {
-			perror("socket() error ");
-			continue;
-		}
-		status = bind(sockfd, rp->ai_addr, rp->ai_addrlen);
-		if (status == -1) {
-			perror("bind() error ");
-			continue;
-		}
-		break;
-	}
-        freeaddrinfo(res);
-	if (rp == NULL) {
-		fprintf(stderr, "Could not bind()\n");
-		exit(EXIT_FAILURE);
-	}
-	struct sockaddr_storage src_addr;
-	socklen_t addrlen = sizeof(src_addr);
-	char buf[BUFSIZ];
-	ssize_t readlen;
-	readlen = recvfrom(sockfd, buf, BUFSIZ, 0,
-				(struct sockaddr *)&src_addr, &addrlen);
-	if (readlen == -1) {
-		perror("recvfrom() error ");
-		exit(EXIT_FAILURE);
-	}
-	char *ipver, ipstr[INET6_ADDRSTRLEN];
-	void *addr;
-	if (src_addr.ss_family == AF_INET6) {
-		ipver = "IPv6";
-		addr = &(((struct sockaddr_in6 *)&src_addr)->sin6_addr);
-	} else {
-		ipver = "IPv4";
-		addr = &(((struct sockaddr_in *)&src_addr)->sin_addr);
-	}
-	inet_ntop(src_addr.ss_family, addr, ipstr, INET6_ADDRSTRLEN);
-	printf("Got an %s connection from %s\n", ipver, ipstr);
-	printf("Receive %d bytes from client\n", readlen);
-	status = sendto(sockfd, buf, readlen, 0 ,
-			(struct sockaddr *)&src_addr , addrlen);
-	if (status == -1) {
-		perror("sendto() error ");
-		exit(EXIT_FAILURE);
-	}
-	printf("Sent %d bytes to client\n", readlen);
-	close(sockfd);
-	return 0;
-}
-</code>
-خروجی client
-  Sent 11 bytes to server
-  ---
-  Hello world
-  ---
-  Receive 11 bytes from server
-خروجی server
-  Got an IPv4 connection from 127.0.0.1
-  Receive 11 bytes from client
-  Sent 11 bytes to client