uint32在C中的一维数组

Question

I'm continuously sending arrays of pixel values (160x120) as a bytestream from LabVIEW to a C-program through TCP/IP. Then I'm converting the bytes to uint32 values and printing the received data in the console application. The goal here, is that I want to divide the received data in 1D arrays, so every 1D array will consists of (160x120=19200) integer values, so it represents a frame. In better words, the array has to collect every 19200 integers of the received data and display them in the console application. Then the same array has to collect the next 19200 integers and display them in the console application and so on. I appreciate if anyone shows how to do it.

WSADATA wsa;
SOCKET s , new_socket;
struct sockaddr_in server , client;
int c;
int iResult;
char recvbuf[DEFAULT_BUFLEN];
int recvbuflen = DEFAULT_BUFLEN;
typedef unsigned int uint32_t;
unsigned int i;
size_t len;
uint32_t* p;
uint32_t value;

p = (uint32_t*)((void*)recvbuf);

do
{
    iResult = recv(new_socket, recvbuf, recvbuflen, 0);
    len = iResult/sizeof(uint32_t);

    for(i=0; i < len; i++)
    {
    value = p[i];
    }
    printf("%d\n", value);

} 
while ( iResult > 0 );

closesocket(new_socket);
WSACleanup();

return 0;

Answer 1

This code is making lots of assumptions about the sizes and alignment of things. On x86 systems this will work fine, but beware systems that require alignment. It is also assuming that both systems have the same endien-ness.

To receive data chunked into 160x120 uint32_t byte chunks (assuming your DEFAULT_BUFLEN is correct):

int receivedCount = 0;
do
{
    iResult = recv( new_socket, 
                    &recvbuf[receivedCount],
                    DEFAULT_BUFLEN-receivedCount,
                    0 );
    if ( iResult == 0 ) break;    //0 == socket closed
    receivedCount += iResult;
    if ( receivedCount < DEFAULT_BUFLEN )
        continue;                 //still receiving full frame
    for(int i=0; i<160*120; i++)
        printf("%d\n",(unsigned int)p[i]);
    receivedCount = 0;
}
while( wantToContinueCapturingFrames );

This will continuously wait for data until a full frame has been received. Once a full frame has been received it will print out the data from the frame. If the remote system closes the connection this will exit without printing any partial frame.

This isn't really sufficient for "real" applications since it is blocking in recv waiting for data. There's no provision to (gracefully) abort without the remote system either sending data or closing the connection, but fixing that isn't really what you are asking about here.