Russian Qt Forum

C
#include <stdio.h>
#include <string.h>
 
#include "lwip/err.h"
#include "lwip/tcp.h"
#if defined (__arm__) || defined (__aarch64__)
#include "xil_printf.h"
#endif
 
int transfer_data() {
	return 0;
}
 
void print_app_header()
{
	xil_printf("\n\r\n\r-----lwIP TCP echo server ------\n\r");
	xil_printf("TCP packets sent to port 6001 will be echoed back\n\r");
}
 
err_t recv_callback(void *arg, struct tcp_pcb *tpcb,
                               struct pbuf *p, err_t err)
{
	/* do not read the packet if we are not in ESTABLISHED state */
	if (!p) {
		tcp_close(tpcb);
		tcp_recv(tpcb, NULL);
		return ERR_OK;
	}
 
	/* indicate that the packet has been received */
	tcp_recved(tpcb, p->len);
 
	/* echo back the payload */
	/* in this case, we assume that the payload is < TCP_SND_BUF */
	if (tcp_sndbuf(tpcb) > p->len) {
		err = tcp_write(tpcb, p->payload, p->len, 1);
	} else
		xil_printf("no space in tcp_sndbuf\n\r");
 
	/* free the received pbuf */
	pbuf_free(p);
 
	return ERR_OK;
}
 
err_t accept_callback(void *arg, struct tcp_pcb *newpcb, err_t err)
{
	static int connection = 1;
 
	/* set the receive callback for this connection */
	tcp_recv(newpcb, recv_callback);
 
	/* just use an integer number indicating the connection id as the
	   callback argument */
	tcp_arg(newpcb, (void*)(UINTPTR)connection);
 
	/* increment for subsequent accepted connections */
	connection++;
 
	return ERR_OK;
}
 
 
int start_application()
{
	struct tcp_pcb *pcb;
	err_t err;
	unsigned port = 7;
 
	/* create new TCP PCB structure */
	pcb = tcp_new();
	if (!pcb) {
		xil_printf("Error creating PCB. Out of Memory\n\r");
		return -1;
	}
 
	/* bind to specified @port */
	err = tcp_bind(pcb, IP_ADDR_ANY, port);
	if (err != ERR_OK) {
		xil_printf("Unable to bind to port %d: err = %d\n\r", port, err);
		return -2;
	}
 
	/* we do not need any arguments to callback functions */
	tcp_arg(pcb, NULL);
 
	/* listen for connections */
	pcb = tcp_listen(pcb);
	if (!pcb) {
		xil_printf("Out of memory while tcp_listen\n\r");
		return -3;
	}
 
	/* specify callback to use for incoming connections */
	tcp_accept(pcb, accept_callback);
 
	xil_printf("TCP echo server started @ port %d\n\r", port);
 
	return 0;
}

Bash
telnet [host [port]]
 

C++ (Qt)
int q = qFromLittleEndian<int>((const uchar*)Data.constData());
qDebug() << q;
 

C
printf("%s\n", *((unsigned char *) &x) == 0 ? "big-endian" : "little-endian"); 

C++ (Qt)
sss = p->payload;
xil_printf("It's OK");
char *ss = "Give me money";
short n = 52;
if (strcmp(sss, ss) == 0)
{
	err = tcp_write(tpcb, n, sizeof(short), 1);
}
else
{
	err = tcp_write(tpcb, "Тут не важно что", 21, 1);
}
	pbuf_free(p);
 

C++ (Qt)
if (strcmp(sss, ss) == 0)
{
	err = tcp_write(tpcb, &n, sizeof(short), 1);
}