Question

首先，感谢大家阅读和帮助，我非常感激第二，我很抱歉，但我还是这个网站的新手，英语不是我的母语，所以我可以做一些格式和语言错误。我提前道歉。
另外，我的C知识不是那么好，但我愿意学习和提高现在，就此事而言：

我需要做的是创建一个客户端和一个服务器，让服务器监听传入的连接然后我让客户端向服务器发送一个非常大的文本文件（我知道它只是一个文件）然后，服务器将对该文件执行一些操作（它将在发送的文件上运行一个脚本，该脚本在输出中生成另一个名为“output.txt”的文件）。然后，服务器需要将output.txt文件发送回客户端。

现在，我有点如何制作客户端和服务器（我在本网站上阅读了beej指南和其他一些内容），甚至我可能犯了一些错误。我需要一些帮助服务器恢复文件，然后调用脚本并将其他文件发送回客户端。现在我所做的是服务器和客户端...我真的不知道该怎么做在旁注中，我使用我在本网站和互联网上找到的文件制作了这些文件，我希望它们不会太乱，因为我对程序员来说并不是那么好。

这是client.c

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


#define SOCKET_PORT "50000"
#define SOCKET_ADR "localhost"
#define filename "/home/aryan/Desktop/input.txt"


void error(const char *msg)
{
    perror(msg);
    exit(0);
}


int main()
{
/* Making the client */
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;

char buffer[256];

portno = atoi(SOCKET_PORT);

sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) 
    error("ERROR opening socket");

server = gethostbyname(SOCKET_ADR);

if (server == NULL) 
{
    fprintf(stderr,"ERROR, no such host\n");
    exit(0);
}

bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *)server->h_addr, 
     (char *)&serv_addr.sin_addr.s_addr,
     server->h_length);
serv_addr.sin_port = htons(portno);
if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) 
    error("ERROR connecting");

/* Time to send the file */
FILE *pf;
unsigned long fsize;

pf = fopen(filename, "rb");
if (pf == NULL) 
{
    printf("File not found!\n");
    return 1;
}
else 
{
    printf("Found file %s\n", filename);

    fseek(pf, 0, SEEK_END);
    fsize = ftell(pf);
    rewind(pf);

    printf("File contains %ld bytes!\n", fsize);
    printf("Sending the file now");
}

while (1) 
{
    // Read data into buffer.  We may not have enough to fill up buffer, so we
    // store how many bytes were actually read in bytes_read.
    int bytes_read = fread(buffer, sizeof(char),sizeof(buffer), pf);
    if (bytes_read == 0) // We're done reading from the file
        break;

    if (bytes_read < 0) 
    {
        error("ERROR reading from file"); 
    }

    // You need a loop for the write, because not all of the data may be written
    // in one call; write will return how many bytes were written. p keeps
    // track of where in the buffer we are, while we decrement bytes_read
    // to keep track of how many bytes are left to write.
    void *p = buffer;
    while (bytes_read > 0) 
    {
        int bytes_written = write(sockfd, buffer, bytes_read);
        if (bytes_written <= 0) 
        {
            error("ERROR writing to socket\n");
        }
        bytes_read -= bytes_written;
        p += bytes_written;
    }
}       

printf("Done Sending the File!\n");
printf("Now Closing Connection.\n");

fclose(pf);
close(sockfd);
return 0;
}

这是server.c：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <signal.h>
#include <pthread.h>

#define SOCKET_PORT 50000
#define filename "/home/aryan/Desktop/output.txt"


void error(const char *msg)
{
    perror(msg);
    exit(1);
}

void* client_thread_proc(void* arg)
{
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n;
FILE *fp;

int thisfd = (int)arg;
printf("Server %d: accepted = %d\n", getpid(), thisfd);

if (thisfd < 0) 
{ 
    printf("Accept error on server\n");
    error("ERROR on accept"); 
    return NULL;
}

printf("Connection %d accepted\n", thisfd);

fp = fopen(filename, "a+b");
if (fp == NULL) 
{
    printf("File not found!\n");
    return NULL;
}
else 
{
    printf("Found file %s\n", filename);
}

/* Time to Receive the File */
while (1)
{
    bzero(buffer,256);
    n = read(thisfd,buffer,255);
    if (n < 0) error("ERROR reading from socket");

    n = fwrite(buffer, sizeof(char), sizeof(buffer), fp);
    if (n < 0) error("ERROR writing in file");

    n = write(thisfd,"I am getting your file...",25);
    if (n < 0) error("ERROR writing to socket");
} /* end child while loop */

fclose(fp);

return NULL;
}

void serve_it(int Client)
{
    void* arg = (void*)Client;
    pthread_t new_thread;
    pthread_create( &new_thread, NULL, &client_thread_proc, arg);
}

/* Making Server */
int main()
{
int sockfd, newsockfd, portno;
socklen_t clilen;
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n;
FILE *fp;

signal (SIGCHLD, SIG_IGN);

sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) 
    error("ERROR opening socket");

bzero((char *) &serv_addr, sizeof(serv_addr));

serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(SOCKET_PORT);

if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) 
      error("ERROR on binding");

listen(sockfd,5);

clilen = sizeof(cli_addr);

while (1)
{
    printf("Server %d accepting connections\n", getpid());

    newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);

    serve_it(newsockfd);
}  // serving loop


close(sockfd);   
return 0; 
}

我想了解如何继续......
如何使用从客户端到服务器的文件创建脚本？
如何将新文件发送回同一客户端？
如果你能帮助我解决代码中的错误，我将不胜感激。

谢谢大家，很抱歉阅读不久。祝你有愉快的一天！

Answer 1

第一个错误：

#define filename = "Home\\Desktop\\input.txt"

应该是

#define filename "Home\\Desktop\\input.txt"

否则预处理器会插入

= "Home\Desktop\input.txt"

不是

"Home\\Desktop\\input.txt"

你期待的。

第二个错误：

int bytes_read = read(filename /* THAT IS WRONG, FILE HANDLE MUST BE HERE */, buffer, strlen(buffer) /* also WRONG, must be MAX_BYTES_IN_BUFFER or something */ );

在这里你必须阅读＆＃34; pf＆＃34; （您已使用fopen（）调用打开它），最后一个参数必须是您要读取的字节数。因此，如果您执行strlen（缓冲区）并且缓冲区在程序运行时开始时包含一些垃圾，您将会崩溃。 strlen（）只能被调用为有效的以零结尾的字符串，它不是数组的大小！

编辑：精心设计的服务器循环：

while (1)
{
    printf("Server %d accepting connections\n", getpid());

    newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);

    serve_it(newsockfd);
}  // serving loop

serve_it（）：

void serve_int(int Client)
{
    void* arg = (void*)Client;
    pthread_t new_thread;
    pthread_create( new_thread, NULL, &client_thread_proc, arg);
}

void* client_thread(void* arg)
{
    int thisfd = (int)arg;
    printf("Server %d: accepted = %d\n", getpid(), thisfd);

    if (thisfd < 0) 
    { 
        printf("Accept error on server\n");
        error("ERROR on accept"); 
        return NULL;
    }

    printf("Connection %d accepted\n", thisfd);

    fp = fopen(filename, "a+b");
    if (fp == NULL) 
    {
        printf("File not found!\n");
        return NULL;
    }
    else 
    {
        printf("Found file %s\n", filename);
    }

    /* Time to Receive the File */
    while (1)
    {
        bzero(buffer,256);
        n = read(thisfd,buffer,255);
        if (n < 0) error("ERROR reading from socket");

        n = fwrite(buffer, sizeof(buffer), 1, fp);
        if (n < 0) error("ERROR writing in file");

        n = write(thisfd,"I am getting your file...",25);
        if (n < 0) error("ERROR writing to socket");
    } /* end child while loop */

    return NULL;
}

使用Unix上的套接字在C中发送和接收文件（服务器/客户端）

1 个答案: