void set_packet_header(char *buf, int size);
void packet_write(int fd_out, const char *buf, size_t size);
void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
-void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len);
int packet_flush_gently(int fd);
int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
int write_packetized_from_fd_no_flush(int fd_in, int fd_out);