Hey guys,

I am having difficulty with the following compiler warning:

[Warning] passing arg 1 of 'write' makes integer from pointer without a cast

#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "cf_packet.h"

HANDLE hPort;
HANDLE handle;

COMMAND_PACKET
  outgoing_response;


BOOL WriteByte(BYTE bybyte)
{
    DWORD iBytesWritten=0;
    DWORD iBytesToRead = 1;
    if(WriteFile(hPort,(LPCVOID) 
        &bybyte,iBytesToRead,&iBytesWritten,NULL)==0)
        return FALSE;
    else return TRUE;
}

BOOL WriteString(const void *instring, int length)
{
    int index;
    BYTE *inbyte = (BYTE *) instring;
    for(index = 0; index< length; ++index)
    {
        if (WriteByte(inbyte[index]) == FALSE)
            return FALSE;
    }
    return TRUE;
}

BOOL ReadByte(BYTE  resp)
{
    BOOL bReturn = TRUE;
    BYTE rx;
    DWORD dwBytesTransferred=0;

    if (ReadFile (hPort, &rx, 1, &dwBytesTransferred, 0)> 0)
    {
        if (dwBytesTransferred == 1)
        {
            resp=rx;
            bReturn  = TRUE;
        }
        else bReturn = FALSE;
    }
    else    bReturn = FALSE;
    return bReturn;
}

BOOL ReadString(void *outstring, int *length)
{
    BYTE data;
    BYTE dataout[4096]={0};
    int index = 0;
    while(ReadByte(data)== TRUE)
    {
        dataout[index++] = data;
    }
    memcpy(outstring, dataout, index);
    *length = index;
    return TRUE;
}

void ClosePort()
{
    CloseHandle(hPort);
    return;
}

HANDLE ConfigureSerialPort(LPCSTR  lpszPortName)
{
    HANDLE handle = NULL;
    DWORD dwError;
    DCB PortDCB;
    COMMTIMEOUTS CommTimeouts;
    // Open the serial port.
    handle = CreateFile (lpszPortName, // Pointer to the name of the port
        GENERIC_READ | GENERIC_WRITE,
        // Access (read-write) mode
        0,              // Share mode
        NULL,           // Pointer to the security attribute
        OPEN_EXISTING,  // How to open the serial port
        0,              // Port attributes
        NULL);          // Handle to port with attribute to copy
    // Initialize the DCBlength member.
    PortDCB.DCBlength = sizeof (DCB);
    // Get the default port setting information.
    GetCommState (handle, &PortDCB);
    // Change the DCB structure settings.
    PortDCB.BaudRate = 115200;              // Current baud
    PortDCB.fBinary = TRUE;               // Binary mode; no EOF check
    PortDCB.fParity = TRUE;               // Enable parity checking
    PortDCB.fOutxCtsFlow = FALSE;         // No CTS output flow control
    PortDCB.fOutxDsrFlow = FALSE;         // No DSR output flow control
    PortDCB.fDtrControl = DTR_CONTROL_ENABLE; // DTR flow control type
    PortDCB.fDsrSensitivity = FALSE;      // DSR sensitivity
    PortDCB.fTXContinueOnXoff = TRUE;     // XOFF continues Tx
    PortDCB.fOutX = FALSE;                // No XON/XOFF out flow control
    PortDCB.fInX = FALSE;                 // No XON/XOFF in flow control
    PortDCB.fErrorChar = FALSE;           // Disable error replacement
    PortDCB.fNull = FALSE;                // Disable null stripping
    PortDCB.fRtsControl = RTS_CONTROL_ENABLE; // RTS flow control
    PortDCB.fAbortOnError = FALSE;        // Do not abort reads/writes on error
    PortDCB.ByteSize = 8;                 // Number of bits/byte, 4-8
    PortDCB.Parity = NOPARITY;            // 0-4=no,odd,even,mark,space
    PortDCB.StopBits = ONESTOPBIT;        // 0,1,2 = 1, 1.5, 2

    // Configure the port according to the specifications of the DCB structure.
    if (!SetCommState (handle, &PortDCB))
    {
        printf("Could not configure serial port\n");
        return NULL;
    }
    // Retrieve the time-out parameters for all read and write operations
    // on the port.
    GetCommTimeouts (handle, &CommTimeouts);
    // Change the COMMTIMEOUTS structure settings.
    CommTimeouts.ReadIntervalTimeout = MAXDWORD;
    CommTimeouts.ReadTotalTimeoutMultiplier = 0;
    CommTimeouts.ReadTotalTimeoutConstant = 0;
    CommTimeouts.WriteTotalTimeoutMultiplier = 0;
    CommTimeouts.WriteTotalTimeoutConstant = 0;
    if (!SetCommTimeouts (handle, &CommTimeouts))
    {
        printf("Could not set timeouts\n");
        return NULL;
    }
    printf("%s", lpszPortName);
    return handle;
}

void send_packet(void)
  {
  //In order to send the entire packet in one call to "write()", we
  //need to place the CRC packed against the data. If data_length
  //happens to be MAX_DATA_LENGTH, then the position of the CRC is
  //outgoing_response.CRC (like you would expect), but if data_length
  //is less, the CRC moves into the data area, packed into the first
  //unused data position.
  //
  //Create a pointer to the first unused data positions.
  word
   *packed_CRC_position;
  packed_CRC_position=
    (word *)&outgoing_response.data[outgoing_response.data_length];
  *packed_CRC_position=
    get_crc((ubyte *)&outgoing_response,outgoing_response.data_length+2,0xFFFF);
  //command, length, data[data_length], crc, crc
   //SendData((ubyte *)&outgoing_response,outgoing_response.data_length+4);
  }
  
  word get_crc(ubyte *bufptr,word len,word seed)
  {
  //CRC lookup table to avoid bit-shifting loops.
  static const word crcLookupTable[256] =
    {0x00000,0x01189,0x02312,0x0329B,0x04624,0x057AD,0x06536,0x074BF,
     0x08C48,0x09DC1,0x0AF5A,0x0BED3,0x0CA6C,0x0DBE5,0x0E97E,0x0F8F7,
     0x01081,0x00108,0x03393,0x0221A,0x056A5,0x0472C,0x075B7,0x0643E,
     0x09CC9,0x08D40,0x0BFDB,0x0AE52,0x0DAED,0x0CB64,0x0F9FF,0x0E876,
     0x02102,0x0308B,0x00210,0x01399,0x06726,0x076AF,0x04434,0x055BD,
     0x0AD4A,0x0BCC3,0x08E58,0x09FD1,0x0EB6E,0x0FAE7,0x0C87C,0x0D9F5,
     0x03183,0x0200A,0x01291,0x00318,0x077A7,0x0662E,0x054B5,0x0453C,
     0x0BDCB,0x0AC42,0x09ED9,0x08F50,0x0FBEF,0x0EA66,0x0D8FD,0x0C974,
     0x04204,0x0538D,0x06116,0x0709F,0x00420,0x015A9,0x02732,0x036BB,
     0x0CE4C,0x0DFC5,0x0ED5E,0x0FCD7,0x08868,0x099E1,0x0AB7A,0x0BAF3,
     0x05285,0x0430C,0x07197,0x0601E,0x014A1,0x00528,0x037B3,0x0263A,
     0x0DECD,0x0CF44,0x0FDDF,0x0EC56,0x098E9,0x08960,0x0BBFB,0x0AA72,
     0x06306,0x0728F,0x04014,0x0519D,0x02522,0x034AB,0x00630,0x017B9,
     0x0EF4E,0x0FEC7,0x0CC5C,0x0DDD5,0x0A96A,0x0B8E3,0x08A78,0x09BF1,
     0x07387,0x0620E,0x05095,0x0411C,0x035A3,0x0242A,0x016B1,0x00738,
     0x0FFCF,0x0EE46,0x0DCDD,0x0CD54,0x0B9EB,0x0A862,0x09AF9,0x08B70,
     0x08408,0x09581,0x0A71A,0x0B693,0x0C22C,0x0D3A5,0x0E13E,0x0F0B7,
     0x00840,0x019C9,0x02B52,0x03ADB,0x04E64,0x05FED,0x06D76,0x07CFF,
     0x09489,0x08500,0x0B79B,0x0A612,0x0D2AD,0x0C324,0x0F1BF,0x0E036,
     0x018C1,0x00948,0x03BD3,0x02A5A,0x05EE5,0x04F6C,0x07DF7,0x06C7E,
     0x0A50A,0x0B483,0x08618,0x09791,0x0E32E,0x0F2A7,0x0C03C,0x0D1B5,
     0x02942,0x038CB,0x00A50,0x01BD9,0x06F66,0x07EEF,0x04C74,0x05DFD,
     0x0B58B,0x0A402,0x09699,0x08710,0x0F3AF,0x0E226,0x0D0BD,0x0C134,
     0x039C3,0x0284A,0x01AD1,0x00B58,0x07FE7,0x06E6E,0x05CF5,0x04D7C,
     0x0C60C,0x0D785,0x0E51E,0x0F497,0x08028,0x091A1,0x0A33A,0x0B2B3,
     0x04A44,0x05BCD,0x06956,0x078DF,0x00C60,0x01DE9,0x02F72,0x03EFB,
     0x0D68D,0x0C704,0x0F59F,0x0E416,0x090A9,0x08120,0x0B3BB,0x0A232,
     0x05AC5,0x04B4C,0x079D7,0x0685E,0x01CE1,0x00D68,0x03FF3,0x02E7A,
     0x0E70E,0x0F687,0x0C41C,0x0D595,0x0A12A,0x0B0A3,0x08238,0x093B1,
     0x06B46,0x07ACF,0x04854,0x059DD,0x02D62,0x03CEB,0x00E70,0x01FF9,
     0x0F78F,0x0E606,0x0D49D,0x0C514,0x0B1AB,0x0A022,0x092B9,0x08330,
     0x07BC7,0x06A4E,0x058D5,0x0495C,0x03DE3,0x02C6A,0x01EF1,0x00F78};

  //Initial CRC value is 0x0FFFF.
  register word
    newCrc;
  newCrc=seed;
  //This algorithim is based on the IrDA LAP example.
  while(len--)
    newCrc = (newCrc >> 8) ^ crcLookupTable[(newCrc ^ *bufptr++) & 0xff];
  //Make this crc match the one's complement that is sent in the packet.
  return(~newCrc);
  }
  
  void SendData(unsigned char *data,int length)
  {
  dword
    bytes_written;
  bytes_written=0;

  if(handle)
    {
    if((bytes_written=write(handle, data, length)) != length)
      printf("SendData(): system call \"write()\" return error.\n  Asked for %d bytes to be written, but %d bytes reported as written.\n",
             length,(int)bytes_written);
    }
  else
    printf("SendData(): \"handle\" is null\n");

  }

int main(void)
{
    //  Can also use COM2, COM3 or COM4 here
    hPort = ConfigureSerialPort("COM1");
    if(hPort == NULL)
    {
        printf("Com port configuration failed\n");
        return -1;
    }
    // Call your ReadString and WriteString functions here
    outgoing_response.command = 31;
    outgoing_response.data[0]=0; //col
    outgoing_response.data[1]=0; //row
    memcpy(&outgoing_response.data[2],">>>This is line 1<<<",20);
    outgoing_response.data_length = 22;  //the col & row position + the 20 char data length
    send_packet();
    getchar();
    getchar();
    ClosePort();
    return 0;
}

Can anyone tell me how to resolve this?

Also is the function write() defined as a C function? If so where can I find the API that includes it so that I can understand it better?

Any input would be greatly appreciated.

write() appears to be a unix function. It is not a Win API function, nor a standard function. Perhaps it works under Windows as part of POSIX support, I don't know. However, the net tells me that it has the following prototype:

int write(int fd, char *Buff, int NumBytes);

fd is a file buffer, not a HANDLE. I doubt you can pass a Windows HANDLE to a function designed for Unix. If it is even possible, you have to typecast as the compiler tells you to do.