C++ 通过套接字发送文件和文本
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时间：2020-08-27 19:33:51 来源:igfitidea点击:
C++ send file and text via socket
提问by
Im trying to send a image using socket but I have to send the file name as well. Im using a code that i send the file but when I send the file name i receive some strange characters in client.
我试图使用套接字发送图像，但我也必须发送文件名。我使用的是发送文件的代码，但是当我发送文件名时，我在客户端收到了一些奇怪的字符。
Client:
客户：
#define PORT 20000
#define LENGTH 512
int main(int argc, char *argv[]){
int sockfd;
int nsockfd;
char revbuf[LENGTH];
struct sockaddr_in remote_addr;
/* Get the Socket file descriptor */
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
fprintf(stderr, "ERROR: Failed to obtain Socket Descriptor! (errno = %d)\n",errno);
exit(1);
}
/* Fill the socket address struct */
remote_addr.sin_family = AF_INET;
remote_addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &remote_addr.sin_addr);
bzero(&(remote_addr.sin_zero), 8);
/* Try to connect the remote */
if (connect(sockfd, (struct sockaddr *)&remote_addr, sizeof(struct sockaddr)) == -1)
{
fprintf(stderr, "ERROR: Failed to connect to the host! (errno = %d)\n",errno);
exit(1);
}
else
printf("[Client] Connected to server at port %d...ok!\n", PORT);
/* Send File to Server */
//if(!fork())
//{
char* fs_name = "house.jpg";
char sdbuf[LENGTH];
char buffer[256];
int n;
fgets(buffer,255,stdin);
bzero(buffer,256);
n = write(sockfd,buffer, strlen(buffer));
if(n<0) printf("Error: sending filename");
printf("[Client] Sending %s to the Server... ", fs_name);
FILE *fs = fopen(fs_name, "r");
if(fs == NULL)
{
printf("ERROR: File %s not found.\n", fs_name);
exit(1);
}
bzero(sdbuf, LENGTH);
int fs_block_sz;
while((fs_block_sz = fread(sdbuf, sizeof(char), LENGTH, fs)) > 0)
{
if(send(sockfd, sdbuf, fs_block_sz, 0) < 0)
{
fprintf(stderr, "ERROR: Failed to send file %s. (errno = %d)\n", fs_name, errno);
break;
}
bzero(sdbuf, LENGTH);
}
printf("Ok File %s from Client was Sent!\n", fs_name);
//}
close (sockfd);
printf("[Client] Connection lost.\n");
return (0);
}
Part of client that sends the text:
发送文本的客户端部分：
char buffer[256];
int n;
fgets(buffer,255,stdin);
bzero(buffer,256);
n = write(sockfd,buffer, strlen(buffer));
if(n<0) printf("Error: sending filename");
Server:
服务器：
#define PORT 20000
#define BACKLOG 5
#define LENGTH 512
int main ()
{
int sockfd;
int nsockfd;
int num;
int sin_size;
struct sockaddr_in addr_local; /* client addr */
struct sockaddr_in addr_remote; /* server addr */
char revbuf[LENGTH];
/* Get the Socket file descriptor */
if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1 )
{
fprintf(stderr, "ERROR: Failed to obtain Socket Descriptor. (errno = %d)\n", errno);
exit(1);
}
else
printf("[Server] Obtaining socket descriptor successfully.\n");
/* Fill the client socket address struct */
addr_local.sin_family = AF_INET; // Protocol Family
addr_local.sin_port = htons(PORT); // Port number
addr_local.sin_addr.s_addr = INADDR_ANY; // AutoFill local address
bzero(&(addr_local.sin_zero), 8); // Flush the rest of struct
/* Bind a special Port */
if( bind(sockfd, (struct sockaddr*)&addr_local, sizeof(struct sockaddr)) == -1 )
{
fprintf(stderr, "ERROR: Failed to bind Port. (errno = %d)\n", errno);
exit(1);
}
else
printf("[Server] Binded tcp port %d in addr 127.0.0.1 sucessfully.\n",PORT);
/* Listen remote connect/calling */
if(listen(sockfd,BACKLOG) == -1)
{
fprintf(stderr, "ERROR: Failed to listen Port. (errno = %d)\n", errno);
exit(1);
}
else
printf ("[Server] Listening the port %d successfully.\n", PORT);
int success = 0;
while(success == 0)
{
sin_size = sizeof(struct sockaddr_in);
/* Wait a connection, and obtain a new socket file despriptor for single connection */
if ((nsockfd = accept(sockfd, (struct sockaddr *)&addr_remote, &sin_size)) == -1)
{
fprintf(stderr, "ERROR: Obtaining new Socket Despcritor. (errno = %d)\n", errno);
exit(1);
}
else
printf("[Server] Server has got connected from %s.\n", inet_ntoa(addr_remote.sin_addr));
char buffer[256];
bzero(buffer,256);
int n = 0;
n = read(nsockfd, buffer, 255);
if (n < 0) error("ERROR reading from socket");
printf("msg: %s\n",buffer);
/*Receive File from Client */
char* fr_name = "/house.jpg";
FILE *fr = fopen(fr_name, "a");
if(fr == NULL)
printf("File %s Cannot be opened file on server.\n", fr_name);
else
{
bzero(revbuf, LENGTH);
int fr_block_sz = 0;
while((fr_block_sz = recv(nsockfd, revbuf, LENGTH, 0)) > 0)
{
int write_sz = fwrite(revbuf, sizeof(char), fr_block_sz, fr);
if(write_sz < fr_block_sz)
{
error("File write failed on server.\n");
}
bzero(revbuf, LENGTH);
if (fr_block_sz == 0 || fr_block_sz != 512)
{
break;
}
}
if(fr_block_sz < 0)
{
if (errno == EAGAIN)
{
printf("recv() timed out.\n");
}
else
{
fprintf(stderr, "recv() failed due to errno = %d\n", errno);
exit(1);
}
}
printf("Ok received from client!\n");
fclose(fr);
}
}
}
}
Part of server that receive the text:
接收文本的服务器部分：
char buffer[256];
bzero(buffer,256);
int n = 0;
n = read(nsockfd, buffer, 255);
if (n < 0) error("ERROR reading from socket");
printf("msg: %s\n",buffer);
Need some help with that. Thanks...
需要一些帮助。谢谢...
采纳答案by jxh
In this code in your client:
在您客户端的这段代码中：
char buffer[256];
int n;
fgets(buffer,255,stdin);
bzero(buffer,256);
n = write(sockfd,buffer, strlen(buffer));
It looks like you are trying to read the file name from the stdinand send it on the sockfd. But. you zero out the buffer before you send it.
看起来您正在尝试从 读取文件名stdin并将其发送到sockfd. 但。在发送之前将缓冲区清零。
