我还是个编程新手。我一直在尽我最大的努力完成这项任务。当我运行程序时，它显示：共发送0个字节，应显示总发送字节数，赋值提示问题：
发送方：
1.发送方应作为./sender调用，其中是要发送给接收方的文件的名称。例如，./sender file.txt将发送名为file.txt的文件。
1.调用时，发送方应打开名为cpsc 351 messagqueue的消息队列，如果不存在，发送方应终止并返回错误。
1.否则，发送方应打开命令行中指定的文件，并按以下步骤进行：
(a)从文件中读取最多4096个字节。
(b)使用mqsend（）和消息优先级1发送通过消息队列读取的字节。
(c)重复前面的步骤，直到到达文件末尾。
(d)当到达文件末尾时，向接收方发送优先级为2的空消息，告知接收方发送完成。
1.终止。
我的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <mqueue.h>
#include <unistd.h>
#include <signal.h>

#define MSQ_NAME "/cpsc351queue"

int main(int argc, char** argv)
{   

    // The file size
    int fileSize = -1;

    // The buffer used to store the message copied
    // copied from the shared memory
    char buff[4096];

    // The variable to hold the message queue ID
    int msqid = -1;

    // The total number of bytes written
    int totalBytesRead = 0;

    // The number of bytes 
    int bytesRead = 0;

    // Whether we are done reading  
    bool finishedReading = false;
    
    // TODO: Define a data structure
    // of type mq_attr to specify a
    // queue that can hold up to 10
    // messages with the maximum message
    // size being 4096 bytes
    mq_attr attr;

    attr.mq_flags = 0;
    attr.mq_maxmsg = 10;
    attr.mq_msgsize = 4096;
    attr.mq_curmsgs = 0;

    // Sanity checks -- make sure the user has provided a file
    if(argc < 2)
    {
        fprintf(stderr, "USAGE: %s <FILE NAME>\n", argv[0]);
        exit(1);
    }

    // Open the file for reading
    int fd = open(argv[1], O_RDONLY);
    
    // Make sure the file was opened
    if(fd < 0)
    {
        perror("open");
        exit(1);
    }
    
    
    // TODO: Gain access to the message queue
    // whose name is defined by the macro
    // MSQ_NAME macro above. We assume that
    // the receiver has allocated the message queue.
    mqd_t qid = mq_open("/cpsc351queue", O_RDWR, 0600, &attr);

    
    //TODO: Loop below attempts to read the 
    // file 4096 bytes at a time.
    // Modify the loop as necessary to send
    // each chunk of data read as message
    // through the message queue. You can use
    // 1 for the priority of the message.


    // Keep writing until all data has been written
    while((totalBytesRead < fileSize) && !finishedReading)
    {
        
        totalBytesRead = read(fd, buff, bytesRead);

        
        bytesRead = mq_send(qid, totalBytesRead, 4096, 1);
    

        // Something went wrong
        if(bytesRead < 0)
        {
            perror("read");
            exit(1);
        }
        // We are at the end of file
        else if(bytesRead == 0)
        {
            // We are at the end of file
            finishedReading = true;     
        }
        
        
        totalBytesRead += bytesRead;
    }
    
    // TODO: Send a message with size of 0
    // to the receiver to tell it that the
    // transmission is done
        

    fprintf(stderr, "Sent a total of %d bytes\n", totalBytesRead);
    
    // TODO: Close the file     
    close(fd);
    return 0;
}