使用Winsock将文件分解成块，然后以二进制形式从客户端发送到C中的服务器吗？

Question

I created an application that send a text file from client to server So far i'm send it as string like this:

fp = fopen(filename, "r");
    if (fp != NULL) {
        newLen = fread(source, sizeof(char), 5000, fp);
            if (newLen == 0) {
                fputs("Error reading file", stderr);
            } else {
    source[++newLen] = '\0'; /* Just to be safe. */
            }
    }else{
        printf("The file %s does not exist :(");
        return 1;
    }


    fclose(fp);

    send(s , source , strlen(source) , 0); //send file

However my professor told me I must send the file in Binary and be ready to accept a file of any size I'm trying to figure out how to send the file in binary and break it into chunks

Answer 1

You can copy it one byte at a time.

Reading/writing more than a byte at a time theoretically would make it read and write more efficiently to disk. But since the binary is likely short, and disk I/O is already internally buffered it probably doesn't make a noticeable difference.

perror() is a convenient function that displays the text associated with an error code returned from the most recent UNIX system call. The text in the quotes is the title it displays before showing you the system message associated with the code.

exit(EXIT_FAILURE) exits with a -1 value which is what scripts can test to see if your program succeeded or failed, as the exit status can be retrieved for a UNIX program.

size_t is an integer type, but it's named size_t to give a hint as to what you're using it for.

If you wanted to transfer more data at a time you could. But 1-byte xfers is simple and safe and it works.

FILE *exein, *exeout;

exein = fopen("filein.exe", "rb");
if (exein == NULL) {
    /* handle error */
    perror("file open for reading");
    exit(EXIT_FAILURE);
}
exeout = fopen("fileout.exe", "wb");
if (exeout == NULL) {
    /* handle error */
    perror("file open for writing");
    exit(EXIT_FAILURE);
}
size_t n, m;
unsigned char buff[8192];
do {
    n = fread(buff, 1, sizeof buff, exein);
    if (n) 
        m = fwrite(buff, 1, n, exeout);
    else   
        m = 0;
} while ((n > 0) && (n == m));
if (m) 
   perror("copy");