Question

我目前正在尝试组建一个程序，允许两个程序在文件之间进行通信，充当数据链接层。

我遇到的问题是，即使我的消息似乎是通过网络发送的，收到的消息后面有一些奇怪的垃圾文本，然后传递给它主文件，垃圾文本全部通过，消息完全消失。非常感谢任何正确方向的指针。

发送程序

main(){

    dlinits("hostname", 43520);
    dlsend("hello");

}

接收程序

#include <string.h>
char* dlrecv();

main(){
    char* test;
    dlinitr(43520);
    strcpy(test,dlrecv());

    printf("%s\n", test);



}

数据链接程序

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#define BUFMAX 100

static int sk;
static struct sockaddr_in remote;
static struct sockaddr_in local;

dlinits(char* host, int port){//initialize sender

    struct hostent *hp;
    sk = socket(AF_INET, SOCK_DGRAM, 0);

    remote.sin_family = AF_INET;

    hp = gethostbyname(host);
    if (hp == NULL){
        printf("Can't find host name\n");
        exit(1);
    }

    bcopy(hp->h_addr,&remote.sin_addr.s_addr,hp->h_length);

    remote.sin_port = ntohs(port);
}

dlinitr(int port){//initialize receiver
    int rlen = sizeof(remote);
    int len = sizeof(local);
    char buf[BUFMAX];

    sk = socket(AF_INET,SOCK_DGRAM,0);

    local.sin_family = AF_INET;
    local.sin_addr.s_addr = INADDR_ANY;
    local.sin_port = htons(port);
    bind (sk, &local,sizeof(local));

    getsockname(sk,&local,&len);

}

dlsend(char* msg){//send data

    printf("%s\n", msg);
    sendto(sk,msg,sizeof(msg)+1,0,&remote,sizeof(remote));
} 

char* dlrecv(){//receive data
    char* msg[BUFMAX];

    recvfrom(sk,msg,BUFMAX,0,&remote,sizeof(remote));
    printf("%s\n", msg);
    return msg;
}

Answer 1

该行

sendto(sk,msg,sizeof(msg)+1,0,&remote,sizeof(remote));

应该是

sendto(sk,msg,strlen(msg)+1,0,&remote,sizeof(remote));

通过UDP套接字发送消息的麻烦

1 个答案: