C套接字，文件后发送消息，TCP

我想通过套接字发送文件，然后我想发送三条消息。 下面的代码工作，但我必须发送第一句话两次。 我的问题是为什么？ 没有一个句子1，接收者显示句子2，句子3和句子3。 这段代码有什么问题？ 我使用的是TCP协议。

Sender.c

char file_size[256]; struct stat file_stat; int sent_bytes = 0; int fd; int offset; int remain_data; fd = open(FILE_TO_SEND, O_RDONLY); if (fd == -1) { fprintf(stderr, "Error opening file --> %s", strerror(errno)); exit(EXIT_FAILURE); } /* Get file stats */ if (fstat(fd, &file_stat) < 0) { fprintf(stderr, "Error fstat --> %s", strerror(errno)); exit(EXIT_FAILURE); } fprintf(stdout, "File Size: \n%d bytes\n", file_stat.st_size); sprintf(file_size, "%d", file_stat.st_size); write(sck, file_size, 256); char buffer[1024] = ""; while (1) { int bytes_read = read(fd, buffer, sizeof(buffer)); if (bytes_read == 0) break; void *p = buffer; while (bytes_read > 0) { int bytes_written = write(sck, p, bytes_read); if (bytes_written <= 0) { // handle errors } bytes_read -= bytes_written; p += bytes_written; } } char sentence[1024]; write(sck, sentence1, 1024); write(sck, sentence1, 1024); write(sck, sentence2, 1024); write(sck, sentence3, 1024); 

Receiver.c

 char buffer[1024] = ""; int sck = *((int*) arg); int file_size; read(sck, buffer, 256); file_size = atoi(buffer); ssize_t len; FILE *received_file; int remain_data = 0; received_file = fopen("plik.pdf", "w"); if (received_file == NULL) { fprintf(stderr, "Failed to open file foo --> %s\n", strerror(errno)); exit(EXIT_FAILURE); } remain_data = file_size; while (((len = recv(sck, buffer, 1024, 0)) > 0) && (remain_data > 0)) { fwrite(buffer, sizeof(char), len, received_file); remain_data -= len; } fclose(received_file); read (sck, buffer, 1024); printf("%s 1\n", buffer); read (sck, buffer, 1024); printf("%s 2\n", buffer); read (sck, buffer, 1024); printf("%s 3\n", buffer); 

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 while ((remain_data > 0) && ((len = recv(sck, buffer, 1024, 0)) > 0))