两个应用程序可以通过UDP数据包进行通信吗？

Question

我正在寻找一种方法来缓解将数据从一个应用程序/进程转移到另一个应用程序的困难，但应该会有某种错误恢复能力。由于UDP是一个现有的协议，可以在网络上运行良好，我不知道它是否也可以被同一操作系统中的进程使用（这里是Windows XP）。

如果是，你可以提供一些核心代码来说明这一点吗？

Answer 1

阅读本http://beej.us/guide/bgnet/output/html/multipage/clientserver.html

listener.c

/* 
** listener.c -- a datagram sockets "server" demo 
*/ 

#include <stdio.h> 
#include <stdlib.h> 
#include <unistd.h> 
#include <errno.h> 
#include <string.h> 
#include <sys/types.h> 
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <arpa/inet.h> 
#include <netdb.h> 

#define MYPORT "4950" // the port users will be connecting to 

#define MAXBUFLEN 100 

// get sockaddr, IPv4 or IPv6: 
void *get_in_addr(struct sockaddr *sa) 
{ 
    if (sa->sa_family == AF_INET) { 
     return &(((struct sockaddr_in*)sa)->sin_addr); 
    } 

    return &(((struct sockaddr_in6*)sa)->sin6_addr); 
} 

int main(void) 
{ 
    int sockfd; 
    struct addrinfo hints, *servinfo, *p; 
    int rv; 
    int numbytes; 
    struct sockaddr_storage their_addr; 
    char buf[MAXBUFLEN]; 
    socklen_t addr_len; 
    char s[INET6_ADDRSTRLEN]; 

    memset(&hints, 0, sizeof hints); 
    hints.ai_family = AF_UNSPEC; // set to AF_INET to force IPv4 
    hints.ai_socktype = SOCK_DGRAM; 
    hints.ai_flags = AI_PASSIVE; // use my IP 

    if ((rv = getaddrinfo(NULL, MYPORT, &hints, &servinfo)) != 0) { 
     fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); 
     return 1; 
    } 

    // loop through all the results and bind to the first we can 
    for(p = servinfo; p != NULL; p = p->ai_next) { 
     if ((sockfd = socket(p->ai_family, p->ai_socktype, 
       p->ai_protocol)) == -1) { 
      perror("listener: socket"); 
      continue; 
     } 

     if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) { 
      close(sockfd); 
      perror("listener: bind"); 
      continue; 
     } 

     break; 
    } 

    if (p == NULL) { 
     fprintf(stderr, "listener: failed to bind socket\n"); 
     return 2; 
    } 

    freeaddrinfo(servinfo); 

    printf("listener: waiting to recvfrom...\n"); 

    addr_len = sizeof their_addr; 
    if ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN-1 , 0, 
     (struct sockaddr *)&their_addr, &addr_len)) == -1) { 
     perror("recvfrom"); 
     exit(1); 
    } 

    printf("listener: got packet from %s\n", 
     inet_ntop(their_addr.ss_family, 
      get_in_addr((struct sockaddr *)&their_addr), 
      s, sizeof s)); 
    printf("listener: packet is %d bytes long\n", numbytes); 
    buf[numbytes] = '\0'; 
    printf("listener: packet contains \"%s\"\n", buf); 

    close(sockfd); 

    return 0; 
} 

talker.c

/* 
** talker.c -- a datagram "client" demo 
*/ 

#include <stdio.h> 
#include <stdlib.h> 
#include <unistd.h> 
#include <errno.h> 
#include <string.h> 
#include <sys/types.h> 
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <arpa/inet.h> 
#include <netdb.h> 

#define SERVERPORT "4950" // the port users will be connecting to 

int main(int argc, char *argv[]) 
{ 
    int sockfd; 
    struct addrinfo hints, *servinfo, *p; 
    int rv; 
    int numbytes; 

    if (argc != 3) { 
     fprintf(stderr,"usage: talker hostname message\n"); 
     exit(1); 
    } 

    memset(&hints, 0, sizeof hints); 
    hints.ai_family = AF_UNSPEC; 
    hints.ai_socktype = SOCK_DGRAM; 

    if ((rv = getaddrinfo(argv[1], SERVERPORT, &hints, &servinfo)) != 0) { 
     fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); 
     return 1; 
    } 

    // loop through all the results and make a socket 
    for(p = servinfo; p != NULL; p = p->ai_next) { 
     if ((sockfd = socket(p->ai_family, p->ai_socktype, 
       p->ai_protocol)) == -1) { 
      perror("talker: socket"); 
      continue; 
     } 

     break; 
    } 

    if (p == NULL) { 
     fprintf(stderr, "talker: failed to bind socket\n"); 
     return 2; 
    } 

    if ((numbytes = sendto(sockfd, argv[2], strlen(argv[2]), 0, 
      p->ai_addr, p->ai_addrlen)) == -1) { 
     perror("talker: sendto"); 
     exit(1); 
    } 

    freeaddrinfo(servinfo); 

    printf("talker: sent %d bytes to %s\n", numbytes, argv[1]); 
    close(sockfd); 

    return 0; 
} 

Answer 2

可以，但在同一台主机上的两个进程之间的通信我敢肯定有更好的方法。不幸的是，我不是Windows的大师，但我确定有一些很棒的本地RPC框架可以使用。 UDP的性能不如本地套接字解决方案，并且您必须处理（理论上可能的）丢包等，这是不必要的。