我想从Linux上的客户端应用程序读取Server上的文件。我在下面提到了服务器和客户端应用程序。
在客户端，我打开一个文件（这是我的要求所必需的）。 客户端接收我在文件上写入的数据。现在，我想将收到的数据从客户端发送到服务器端，并将回送给客户端。
我遇到服务器接受客户端连接的问题。我很高兴有一个解决方案，我完全犯了错误。我也很感激如果我得到代码的解决方案。提前谢谢。
Server.C
#include<stdio.h>
#define BufferLength 100
/* Server port number */
#define SERVPORT 3389
int main(int argc, char *argv[])
{
/* Variable and structure definitions. */
int sd, sd2, rc, length = sizeof(int);
int totalcnt = 0, on = 1;
char temp;
char buffer[BufferLength];
//char data[BufferLength];
struct sockaddr_in serveraddr;
struct sockaddr_in their_addr;
fd_set read_fd;
struct timeval timeout;
timeout.tv_sec = 15;
timeout.tv_usec = 0;
/*To read xillybus*/
// FILE *fp;
// fp = fopen("/dev/xillybus_read_8", "r");
// if(fp==NULL)
// {
// printf("Error file open\n");
// exit(-1);
// }
// else{
// printf("File found %s\n", fp);
// }
/* Get a socket descriptor */
if((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
perror("Server-socket() error");
exit (-1);
}
else
{
printf("Server-socket() is OK\n");
}
/* Allow socket descriptor to be reusable */
if((rc = setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on))) < 0)
{
perror("Server-setsockopt() error");
close(sd);
exit (-1);
}
else
{
printf("Server-setsockopt() is OK\n");
}
/* bind to an address */
memset(&serveraddr, 0x00, sizeof(struct sockaddr_in));
serveraddr.sin_family = AF_INET;
serveraddr.sin_port = htons(SERVPORT);
serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
printf("Using %s, listening at %d\n", inet_ntoa(serveraddr.sin_addr), SERVPORT);
if((rc = bind(sd, (struct sockaddr *)&serveraddr, sizeof(serveraddr))) < 0)
{
perror("Server-bind() error");
close(sd);
exit(-1);
}
else
{
printf("Server-bind() is OK\n");
}
/* Up to 10 clients can be queued */
if((rc = listen(sd, 10)) < 0)
{
perror("Server-listen() error");
close(sd);
exit (-1);
}
else
{
printf("Server-Ready for client connection...\n");
}
/* accept() the incoming connection request. */
int sin_size = sizeof(struct sockaddr_in);
if((sd2 = accept(sd, (struct sockaddr *)&their_addr, &sin_size)) < 0)
{
perror("Server-accept() error");
close(sd);
exit (-1);
}
else
{
printf("Server-accept() is OK\n");
}
/*client IP*/
printf("Server-new socket, sd2 is OK...\n");
printf("Got connection from the client: %s\n", inet_ntoa(their_addr.sin_addr));
/* Wait for up to 15 seconds on */
/* select() for data to be read. */
FD_ZERO(&read_fd);
FD_SET(sd2, &read_fd);
rc = select(sd2+1, &read_fd, NULL, NULL, &timeout);
if((rc == 1) && (FD_ISSET(sd2, &read_fd)))
{
/* Read data from the client. */
totalcnt = 0;
while(totalcnt < BufferLength)
{
/* read() from client */
rc = read(sd2, &buffer[totalcnt], (BufferLength - totalcnt));
if(rc < 0)
{
perror("Server-read() error");
close(sd);
close(sd2);
exit (-1);
}
else if (rc == 0)
{
printf("Client program has issued a close()\n");
close(sd);
close(sd2);
exit(-1);
}
else
{
totalcnt += rc;
printf("Server-read() is OK\n");
}
}
}
else if (rc < 0)
{
perror("Server-select() error");
close(sd);
close(sd2);
exit(-1);
}
/* rc == 0 */
else
{
printf("Server-select() timed out.\n");
close(sd);
close(sd2);
exit(-1);
}
/* Shows the data */
printf("Received data from the client: %s\n", buffer);
printf("Server-Echoing back to client...\n");
/*Write function*/
rc = write(sd2, buffer, totalcnt);
if(rc != totalcnt)
{
perror("Server-write() error");
rc = getsockopt(sd2, SOL_SOCKET, SO_ERROR, &temp, &length);
if(rc == 0)
{
/* Print out the asynchronously */
/* received error. */
errno = temp;
perror("SO_ERROR was: ");
}
else
{
printf("Server-write() is OK\n");
}
close(sd);
close(sd2);
exit(-1);
}
/******************************************/
close(sd2);
close(sd);
exit(0);
return 0;
}
Client.c
#include<stdio.h>
#define BufferLength 100
#define SERVER "00.00.00.00"
/* Server's port number */
#define SERVPORT 3389
/* set the server name in the #define SERVER ... */
int main(int argc, char *argv[])
{
/* Variable and structure definitions. */
int sd, rc, length = sizeof(int);
struct sockaddr_in serveraddr;
char buffer[BufferLength];
char server[255];
char temp;
int totalcnt = 0;
struct hostent *hostp;
//char data[500] = "Hello ravi !!! "; // writes data to the server
/*To open directory and read the xillybus*/
FILE *fp;
char s[100];
fp = fopen("/dev/xillybus_read_8", "r");
if(!fp)
return 1;
while(fgets(s,100,fp)!=NULL){
printf("%s ", s);
}
//fclose(fp);
/******************************************/
/* get a socket descriptor */
if((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
perror("Client-socket() error");
exit(-1);
}
else
{
printf("Client-socket() OK\n");
}
/*If the server hostname is supplied*/
if(argc > 1)
{
/*Use the supplied argument*/
strcpy(server, argv[1]);
printf("Connecting to the server %s, port %d ...\n", server, SERVPORT);
}
else
{
/*Use the default server name or IP*/
strcpy(server, SERVER);
memset(&serveraddr, 0x00, sizeof(struct sockaddr_in));
serveraddr.sin_family = AF_INET;
serveraddr.sin_port = htons(SERVPORT);
}
if((serveraddr.sin_addr.s_addr = inet_addr(server)) == (unsigned long)INADDR_NONE)
{
/* get host address */
hostp = gethostbyname(server);
if(hostp == (struct hostent *)NULL)
{
printf("HOST NOT FOUND --> ");
/* h_errno is usually defined */
/* in netdb.h */
printf("h_errno = %d\n",h_errno);
printf("---This is a client program---\n");
printf("Command usage: %s <server name or IP>\n", argv[0]);
close(sd);
exit(-1);
}
memcpy(&serveraddr.sin_addr, hostp->h_addr, sizeof(serveraddr.sin_addr));
}
/* connect() to server. */
if((rc = connect(sd, (struct sockaddr *)&serveraddr, sizeof(serveraddr))) < 0)
{
perror("Client-connect() error");
close(sd);
exit(-1);
}
else
{
printf("Connection established...\n");
printf("Sending some string to the server %s...\n", server);
}
/* Write() some string to the server. */
//rc = write(sd, data, sizeof(data));
rc = write(sd,fp, sizeof(fp)); // here is my write function
if(rc < 0)
{
perror("Client-write() error");
rc = getsockopt(sd, SOL_SOCKET, SO_ERROR, &temp, &length);
if(rc == 0)
{
/* Print out the asynchronously received error. */
errno = temp;
perror("SO_ERROR was");
}
close(sd);
exit(-1);
}
else
{
printf("Client-write() is OK\n");
printf("String successfully sent \n");
printf("Waiting the %s to echo back...\n", server);
}
totalcnt = 0;
/* Read data from the server. */
while(totalcnt < BufferLength)
{
rc = read(sd, &buffer[totalcnt], BufferLength-totalcnt); //&buffer[totalcnt],BufferLength-totalcnt
if(rc < 0)
{
perror("Client-read() error");
close(sd);
exit(-1);
}
else if (rc == 0)
{
printf("Server program has issued a close()\n");
close(sd);
exit(-1);
}
else
{
totalcnt += rc;
}
}
printf("Client-read() is OK\n");
printf("Echoed data from the server: %s\n", buffer); //data ->buffer
/* Close socket descriptor from client side. */
close(sd);
exit(0);
return 0;
}
答案 0 :(得分：0)
在您的client.c程序中，您尝试向服务器发送FILE*。您发送的是客户端程序中文件描述符的地址，不文件中包含的文本。
您只发送4或8个字节（取决于架构32或64位），而服务器在回显任何内容之前等待至少100个字节。所以这两个程序都完全按照您编程的方式完成 - 但不是您所期望的。
要发送文件的内容，请在char数组中读取文件并发送char数组。您可以迭代读取一个缓冲区的文件并发送缓冲区。但是没有魔法允许发送整个文件。