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;}
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C++ (Qt)int q = qFromLittleEndian<int>((const uchar*)Data.constData());qDebug() << q;
Cprintf("%s\n", *((unsigned char *) &x) == 0 ? "big-endian" : "little-endian");
