CreateFile Failed problem

Okay, So I am new to programming and am trying to transfer data from a machine via RS232 to an "adapter" program that allows connection to a "client or agent" program that sends the data to the web(localhost) in .xml format. Basically a socket setup. Both programs seem to be working fine, but when I connected the client program to the "adapter", it says CreateFile Failed.

When I run the first program, executeable window pops up and says:
Server Started, waiting on port 7878

Then when I connect to the localhost it says:
Server Started, waiting on port 7878
Connected to: 127.0.0.1 on port 2816
CreateFile Failed

I am pretty sure the port numbers do not need to match since I am trying to view this data on the local host. 7878 is just the default port number in the adapter program.

I am not sure which section of code to look at so can someone tell me where to look to fix this problem? I am not sure if it is an .xml proble, schema problem, or what the problem is. Thanks for any advice or help you can give me.

From MSDN article CreateFile

Quote:

---

Return Value

If the function succeeds, the return value is an open handle to the specified file, device, named pipe, or mail slot.

If the function fails, the return value is INVALID_HANDLE_VALUE. To get extended error information, call GetLastError.

---

Is there a problem with this file?

serial.win32.cpp-external dependency file

Code:

---


bool Serial::connect()
{
  if (mConnected)
  {
    printf("You are already connected, please disconnect first\n");
    return false;
  }
 
  COMMTIMEOUTS cto;
  DCB dcb;
  char parity, stop_bits;
  int speed;
                 
  if (mFd != INVALID_HANDLE_VALUE && !CloseHandle(mFd)){
    printf("Can't close comm port");
    return false;
  }
 
  mFd = CreateFileA(mDevice,
                    GENERIC_READ|GENERIC_WRITE,
                    0,
                    NULL,
                    OPEN_EXISTING,
                    0,
                    NULL);
       
  if(mFd == INVALID_HANDLE_VALUE) {
    char port[64];
    strcpy(port, "\\\\.\\");
    strcat(port, mDevice);
    mFd = CreateFileA(port,
                      GENERIC_READ|GENERIC_WRITE,
                      0,
                      NULL,
                      OPEN_EXISTING,
                      0,
                      NULL);
               
    if(mFd == INVALID_HANDLE_VALUE) {
      printf("CreateFile Failed \n");
      return false;
    }
  }
       
  if(!SetupComm(
      mFd,        // handle of communications device
      1024,        // size of input buffer
      1024        // size of output buffer
      )
    ){
    printf("SetupComm failed \n");
    CloseHandle(mFd);
    return false;
  }
       
  // verify baudrate and pairty
       
  // set DCB
  switch (mBaud) {
  case 110:
    speed = CBR_110;
    break;
  case 300:
    speed = CBR_300;
    break;
  case 600:
    speed = CBR_600;
    break;
  case 1200:
    speed = CBR_1200;
    break;
  case 2400:
    speed = CBR_2400;
    break;
  case 4800:
    speed = CBR_4800;
    break;
  case 9600:
    speed = CBR_9600;
    break;
  case 19200:
    speed = CBR_19200;
    break;
  case 38400:
    speed = CBR_38400;
    break;
  case 57600:
    speed = CBR_57600;
    break;
  case 115200:
    speed = CBR_115200;
    break;
  default:
    speed = CBR_9600;
    printf("WARNING Unknown baud rate %d for %s (B9600 used)\n",
          mBaud, mDevice);
  }

  if (strncmp(mParity, "none", 4) == 0) {
    parity = NOPARITY;
  } else if (strncmp(mParity, "even", 4) == 0) {
    parity = EVENPARITY;
  } else {
    /* odd */
    parity = ODDPARITY;
  }

  /* Stop bit (1 or 2) */
  if (mStopBit == 1)
    stop_bits = ONESTOPBIT;
  else /* 2 */
    stop_bits = TWOSTOPBITS;

  memset(&dcb,0,sizeof(dcb));
  dcb.DCBlength = sizeof(dcb);
  dcb.BaudRate = speed;
  dcb.fBinary = TRUE;
  dcb.StopBits = stop_bits;
  dcb.Parity = parity;
  dcb.ByteSize = mDataBit;
       

  dcb.fDtrControl = DTR_CONTROL_DISABLE;
  dcb.fOutxCtsFlow = FALSE ;       
  dcb.fRtsControl = RTS_CONTROL_DISABLE;
       
  // setup software flow control
  dcb.fInX = dcb.fOutX = 0;
               
  memset(&cto, 0, sizeof(cto));
  cto.ReadIntervalTimeout = 100;
  cto.ReadTotalTimeoutMultiplier = 1;
  cto.ReadTotalTimeoutConstant = 1000;
  cto.WriteTotalTimeoutMultiplier = cto.ReadIntervalTimeout;
  cto.WriteTotalTimeoutConstant = 1000;       

  if(!SetCommTimeouts(mFd, &cto)){
    printf("SetTimeouts failed ");
        CloseHandle(mFd);
    return false;
  }       
       
  if(!SetCommState(mFd, &dcb)){
    printf("SetCommState failed \n");
        CloseHandle(mFd);
    return false;
  }
       
  mConnected = true;
 
  return true;
}

bool Serial::disconnect()
{
  if (mConnected)
  {
    CloseHandle(mFd);
    mConnected = false;
        mFd = INVALID_HANDLE_VALUE;
    return true;
  }
  else
  {
    return false;
  }
}

int Serial::read(char *aBuffer, int aLen)
{
  int ret;
  DWORD bytes_read;
  if(ReadFile(mFd, aBuffer, aLen, &bytes_read, NULL) )
  {
    ret = bytes_read;
  }
  else
  {
    DWORD errors;
    COMSTAT status;
   
    ClearCommError(mFd, &errors, &status);
    ret = -1;
  }

  return ret;
}

int Serial::write(const char *aBuffer, int aLen)
{
  DWORD bytes_written;
  int ret;
  if(WriteFile(mFd, aBuffer, aLen, &bytes_written, NULL) )
  {
    ret = bytes_written;
  }
  else
  {
    DWORD errors;
    COMSTAT status;
    ClearCommError(mFd,&errors,&status);
    ret = -1;
  }
  return ret;

---

Please edit your post adding Code tags around code snippets. and don|t forget thr indentations.
Also read Announcement: Before you post....

Please add code tags.

Also what does GetLastError() tell you that Victor suggested in reply #2?

How do I call the GetLastError()? Sorry, this is all very new to me

Quote:

---

Originally Posted by wklove2003

How do I call the GetLastError()? Sorry, this is all very new to me

---

:confused:

Seriously, how can you not know how to call a function when the code you posted is full of other function calls?? What about that call to CreateFile(), strcpy, etc.? You seem to be doing fine calling those functions.

GetLastError() is just another function you call when you get an error. Just call the function and see what the value that is returned to you is. That value is the error condition.

Regards,

Paul McKenzie

Quote:

---

Originally Posted by wklove2003

How do I call the GetLastError()? Sorry, this is all very new to me

---

Didn't you read the documentation about GetLastError? :confused:
Didn't you try to search for CreateFile GetLastError example? :confused:
Well, very simple:

Code:

---

  mFd = CreateFileA(mDevice,
                    GENERIC_READ|GENERIC_WRITE,
                    0,
                    NULL,
                    OPEN_EXISTING,
                    0,
                    NULL);
       
  if(mFd == INVALID_HANDLE_VALUE)
 {
      DWORD dwError = GetLastError();
      // some code to output or display error message
      ...
}

---

I am not getting any message, they are running the same way. No errors pop up in the call stack for either program. Nothing happens when I inserted the GetLastError function

GetLastError does NOT display any message. It only returns you the error code!
It's up to you how to output or display error message. :cool:

Quote:

---

Originally Posted by wklove2003

I am not getting any message, they are running the same way. No errors pop up in the call stack for either program. Nothing happens when I inserted the GetLastError function

---

Step through your code in a debugger and look at the dwError value.

Quote:

---

Originally Posted by wklove2003

I am not getting any message, they are running the same way. No errors pop up in the call stack for either program. Nothing happens when I inserted the GetLastError function

---

The GetLastError() function returns to you a value -- that value is the error code. You are to do with that error code whatever you need to do with it -- log it, display it in your own window, inspect it, who knows.

You are under the misconception that GetLastError() should only be used when you have an error in your program. That is false. It should be called every time you call a Windows API function and that function fails. It should be part of your program, and right now, it isn't. You are calling many Windows API functions in the code you posted, and you don't call GetLastError() even once for when they fail.

Yes, you are checking for a return value from the functions you're calling themselves, but you must call the "second line of defense", which is the GetLastError() function to tell you exactly why the function failed. In addition, you should also learn to use FormatMessage() in conjuction with GetLastError(). Therefore your code is not really complete.

Secondly, if you think about it for a moment, why would an API function such as GetLastError() want to display error boxes? That is up to the programmer and application as to how to display or record errors. What if I don't want error messages popping up all over the place, and instead just want to log the error number in a file?

Regards,

Paul McKenzie

Ok, so when I try to step through in debug and putting @err,h in Watch window I get:

Watch:
@err,h CXX0026: Error: bad format string

CallStack:
> haas.exe!main(int aArgc, char * * aArgv) Line 40 C++
haas.exe!__tmainCRTStartup() Line 555 + 0x17 bytes C
kernel32.dll!7c817077()
[Frames below may be incorrect and/or missing, no symbols loaded for kernel32.dll]

Code:

---

#include "internal.hpp"
#include "haas_adapter.hpp"
#include "server.hpp"
#include "string_buffer.hpp"

int main(int aArgc, char *aArgv[])
{
  int port = 7878;
  int i = 0;
  bool debug = false;
  bool positions = false;

  while (aArgc > 0 && aArgv[i][0] == '-')
  {
    if (aArgv[i][1] == 'd')
      debug = true;
    else if (aArgv[i][1] == 'p')
      positions = true;
    else
    {
      printf("Invalid option: %s\n", aArgv[i]);
      printf("Usage: %s [-dp] <Serial_COM> [port]\n", aArgv[0]);
      exit(1);
    }

    i++;
    aArgc--;
  }

  if (aArgc > 2)
    port = atoi(aArgv[i + 1]);
   
  /* Construct the adapter and start the server */
  HaasSerial *serial = new HaasSerial(aArgv[i], 19200, "none", 7, 1, debug);
  HaasAdapter adapter(port, serial, positions);
  adapter.startServer();
 
  return 0;
}

---

Line 40 is:
int main(int aArgc, char *aArgv[]) Line 39
{ Line 40

Any Ideas?

Quote:

---

Originally Posted by wklove2003

Ok, so when I try to step through in debug and putting @err,h in Watch window I get:

---

???

What is all of this stuff? How hard is it to call the GetLastError() function and inspect the error value returned??? If you don't want to ignore what we're telling you, then why post?

Regards,

Paul McKenzie

Sorry, I just havent been able to get a GetLastError() function to return anything. That is why I started trying other things. Seems to only cause problems when I try putting something in there. When I do not get any problems, I also do not get any result so I am not sure what I am doing wrong.

I am a complete newb to programming, but unfortunately, have been handed a project that is dealing with a fairly complex program that was downloaded. So most of the code I have posted, I did not actually do. Just trying to get this program to run properly ASAP

Quote:

---

Originally Posted by wklove2003

Sorry, I just havent been able to get a GetLastError() function to return anything.

---

What do you mean "not return anything?"

Code:

---

if (mFd == INVALID_HANDLE_VALUE)
 {
    DWORD dwError = GetLastError();
    printf("The value of the error code is %d\n", dwError);
}

---

That is all we have been waiting for all this time. What is the error value?

In general:

Code:

---

if ( ThisFunctionCallReturnedFailure )
{
    DWORD dwError  = GetLastError( );
    // dwError now has the reason code for why the function failed
}

---

That is what your original code was missing -- you never checked at all for the reason code for the failure. All you did was check for failure, and all we asked you to do is go further and check the reason for the failure by calling GetLastError(). That doesn't sound complex to me.

Quote:

---

I am a complete newb to programming, but unfortunately, have been handed a project that is dealing with a fairly complex program that was downloaded. So most of the code I have posted, I did not actually do. Just trying to get this program to run properly ASAP

---

What we asked you to do has nothing to do with the size or complexity of the program.

All we wanted was you to make a single function call, GetLastError() and see what value is returned, instead of being in the dark as to why CreateFile fails. If you can't do that, then may I suggest you get someone else to finish your program, since what we asked is the simplest of things.

Regards,

Paul McKenzie

Quote:

---

Originally Posted by wklove2003

Sorry, I just havent been able to get a GetLastError() function to return anything.

---

Post the code that you written that shows us the GetLastError( ) calls. You need to call GetLastError immediately after an error occurs in another api call; otherwise it doesn't work. See the CreateFileA example that Victor posted a while ago.

...

Just trying to get this program to run properly ASAP[/QUOTE]The folks replying here are trying to help you. What you need to do is do what they suggest. It's also helpful if you post back code of what you've done rather than trying to describe what you think you did.

For example, you mentioned that you haven't been able to get GetLastError( ) to return anything. Without seeing the code, we can only guess where you put it or how you called it. If you post the code, we can immediately spot any errors.

"The value of the error code is 2"

That is saying that it cannot find the specified file correct? So I know that should be self explanatory, but can you explain to me what file it is talking about and what to do to correct this?

On a seperate note, I do appreciate you guys for trying to help and I apologize.

Quote:

---

Originally Posted by wklove2003

"The value of the error code is 2"

That is saying that it cannot find the specified file correct? So I know that should be self explanatory, but can you explain to me what file it is talking about and what to do to correct this?

---

Who knows what file it's talking about when you haven't included the code.

How come you haven't posted the code after being asked several times to do so? Do you actually read the replies?

Code:

---

bool Serial::connect()
{
  if (mConnected)
  {
    printf("You are already connected, please disconnect first\n");
    return false;
  }
 
  COMMTIMEOUTS cto;
  DCB dcb;
  char parity, stop_bits;
  int speed;
                 
  if (mFd != INVALID_HANDLE_VALUE && !CloseHandle(mFd)){
    printf("Can't close comm port");
    return false;
  }
 
  mFd = CreateFileA(mDevice,
                    GENERIC_READ|GENERIC_WRITE,
                    0,
                    NULL,
                    OPEN_EXISTING,
                    0,
                    NULL);
       
  if(mFd == INVALID_HANDLE_VALUE){
    char port[64];
    strcpy(port, "\\\\.\\");
    strcat(port, mDevice);
    mFd = CreateFileA(port,
                      GENERIC_READ|GENERIC_WRITE,
                      0,
                      NULL,
                      OPEN_EXISTING,
                      0,
                      NULL);
               
    if(mFd == INVALID_HANDLE_VALUE){
            DWORD dwError = GetLastError();
    printf("The value of the error code is %d\n", dwError);
        printf("CreateFile Failed \n");
      return false;
    }
  }

  if(!SetupComm(
      mFd,        // handle of communications device
      1024,        // size of input buffer
      1024        // size of output buffer
      )
    ){
    printf("SetupComm failed \n");
    CloseHandle(mFd);
    return false;
  }
       
  // verify baudrate and pairty
       
  // set DCB
  switch (mBaud) {
  case 110:
    speed = CBR_110;
    break;
  case 300:
    speed = CBR_300;
    break;
  case 600:
    speed = CBR_600;
    break;
  case 1200:
    speed = CBR_1200;
    break;
  case 2400:
    speed = CBR_2400;
    break;
  case 4800:
    speed = CBR_4800;
    break;
  case 9600:
    speed = CBR_9600;
    break;
  case 19200:
    speed = CBR_19200;
    break;
  case 38400:
    speed = CBR_38400;
    break;
  case 57600:
    speed = CBR_57600;
    break;
  case 115200:
    speed = CBR_115200;
    break;
  default:
    speed = CBR_9600;
    printf("WARNING Unknown baud rate %d for %s (B9600 used)\n",
          mBaud, mDevice);
  }

  if (strncmp(mParity, "none", 4) == 0) {
    parity = NOPARITY;
  } else if (strncmp(mParity, "even", 4) == 0) {
    parity = EVENPARITY;
  } else {
    /* odd */
    parity = ODDPARITY;
  }

  /* Stop bit (1 or 2) */
  if (mStopBit == 1)
    stop_bits = ONESTOPBIT;
  else /* 2 */
    stop_bits = TWOSTOPBITS;

  memset(&dcb,0,sizeof(dcb));
  dcb.DCBlength = sizeof(dcb);
  dcb.BaudRate = speed;
  dcb.fBinary = TRUE;
  dcb.StopBits = stop_bits;
  dcb.Parity = parity;
  dcb.ByteSize = mDataBit;
       

  dcb.fDtrControl = DTR_CONTROL_DISABLE;
  dcb.fOutxCtsFlow = FALSE ;       
  dcb.fRtsControl = RTS_CONTROL_DISABLE;
       
  // setup software flow control
  dcb.fInX = dcb.fOutX = 0;
               
  memset(&cto, 0, sizeof(cto));
  cto.ReadIntervalTimeout = 100;
  cto.ReadTotalTimeoutMultiplier = 1;
  cto.ReadTotalTimeoutConstant = 1000;
  cto.WriteTotalTimeoutMultiplier = cto.ReadIntervalTimeout;
  cto.WriteTotalTimeoutConstant = 1000;       

  if(!SetCommTimeouts(mFd, &cto)){
    printf("SetTimeouts failed ");
        CloseHandle(mFd);
    return false;
  }       
       
  if(!SetCommState(mFd, &dcb)){
    printf("SetCommState failed \n");
        CloseHandle(mFd);
    return false;
  }
       
  mConnected = true;
 
  return true;
}

bool Serial::disconnect()
{
  if (mConnected)
  {
    CloseHandle(mFd);
    mConnected = false;
        mFd = INVALID_HANDLE_VALUE;
    return true;
  }
  else
  {
    return false;
  }
}

int Serial::read(char *aBuffer, int aLen)
{
  int ret;
  DWORD bytes_read;
  if(ReadFile(mFd, aBuffer, aLen, &bytes_read, NULL) )
  {
    ret = bytes_read;
  }
  else
  {
    DWORD errors;
    COMSTAT status;
   
    ClearCommError(mFd, &errors, &status);
    ret = -1;
  }

  return ret;
}

int Serial::write(const char *aBuffer, int aLen)
{
  DWORD bytes_written;
  int ret;
  if(WriteFile(mFd, aBuffer, aLen, &bytes_written, NULL) )
  {
    ret = bytes_written;
  }
  else
  {
    DWORD errors;
    COMSTAT status;
    ClearCommError(mFd,&errors,&status);
    ret = -1;
  }
  return ret;
}

---

The code you are looking for?

Why not also print out the port along with the error code so you know what path is failing?

You're also just blindly retrying and don't check the GetLastError value on the first attempt. Maybe your error is something different than with the 2nd attempt?

Code:

---

mFd = CreateFileA(mDevice,
                    GENERIC_READ|GENERIC_WRITE,
                    0,
                    NULL,
                    OPEN_EXISTING,
                    0,
                    NULL);
       
if(mFd == INVALID_HANDLE_VALUE)
{
    printf("CreateFile on %s failed with error code: %d \n"
      , mDevice
      , GetLastError( ) );
    char port[64];
    strcpy(port, "\\\\.\\");
    strcat(port, mDevice);
    mFd = CreateFileA(port,
                      GENERIC_READ|GENERIC_WRITE,
                      0,
                      NULL,
                      OPEN_EXISTING,
                      0,
                      NULL);
               
    if(mFd == INVALID_HANDLE_VALUE)
    {
      printf("CreateFile on %s failed with error code: %d \n"
        , port
        , GetLastError( ) );

      printf("CreateFile Failed \n");
     
      return false;
    }

  return true;
}

---

Code:

---

bool Serial::connect()
{
  if (mConnected)
  {
    printf("You are already connected, please disconnect first\n");
    return false;
  }
 
  COMMTIMEOUTS cto;
  DCB dcb;
  char parity, stop_bits;
  int speed;
                 
  if (mFd != INVALID_HANDLE_VALUE && !CloseHandle(mFd)){
    printf("Can't close comm port");
    return false;
  }
 
  mFd = CreateFileA(mDevice,
                    GENERIC_READ|GENERIC_WRITE,
                    0,
                    NULL,
                    OPEN_EXISTING,
                    0,
                    NULL);
       
  if(mFd == INVALID_HANDLE_VALUE)
  {
    printf("CreateFile on %s failed with error code: %d \n"
      , mDevice
      , GetLastError( ) );
          char port[64];
    strcpy(port, "\\\\.\\");
    strcat(port, mDevice);
    mFd = CreateFileA(port,
                      GENERIC_READ|GENERIC_WRITE,
                      0,
                      NULL,
                      OPEN_EXISTING,
                      0,
                      NULL);
               
    if(mFd == INVALID_HANDLE_VALUE){
            printf("CreateFile on %s failed with error code: %d \n"
        , port
        , GetLastError( ) );
        printf("CreateFile Failed \n");
      return false;
    }
  }

---

"CreateFile Failed
CreateFile on C:\Documents an=failed with error code: 2
CreateFile on \\.\C:\Documents an=failed with error code: 2"

Why did it not show the full path?

Now we're getting somewhere. Isn't it much easier to debug now that you're printing out some debugging info?

Quote:

---

Originally Posted by wklove2003

"CreateFile Failed
CreateFile on C:\Documents an=failed with error code: 2
CreateFile on \\.\C:\Documents an=failed with error code: 2"

Why did it not show the full path?

---

How large is the mDevice buffer? Is the buffer too small and truncating your string?

Btw, is there any reason you don't use CString instead of the old fashioned string buffers?

Most of this was written by someone else, so I am not sure why they did not use CString.

Here is the string_buffer.cpp

Code:

---

#include "internal.hpp"
#include "string_buffer.hpp"

StringBuffer::StringBuffer(const char *aString)
{
  mLength = mSize = 0;
  mTimestamp[0] = 0;
  if (aString != 0)
  {
    append(aString);
  }
  else
  {
    mBuffer = 0;
  }
}

StringBuffer::~StringBuffer()
{
  if (mBuffer != 0)
    free(mBuffer);
}

const char *StringBuffer::append(const char* aString)
{
  /* Include additional length for timestamp */
  size_t len = strlen(aString);
  size_t totalLength = mLength + len;
  size_t tsLen = strlen(mTimestamp);
  if (mLength == 0)
    totalLength += tsLen;
  if (totalLength >= mSize)
  {
    size_t newLen = ((totalLength / 1024) + 1) * 1024;
    char *newBuffer = (char*) malloc(newLen);
    memcpy(newBuffer, mBuffer, mLength);
   
    free(mBuffer);
    mBuffer = newBuffer;
    mSize = newLen;
  }
 
  if (mLength == 0 && tsLen > 0)
  {
    strcpy(mBuffer, mTimestamp);
    mLength += tsLen;
  }

  strcpy(mBuffer + mLength, aString);
  mLength += len;
 
  return mBuffer;
}

void StringBuffer::reset()
{
  if (mBuffer != 0)
  {
    mBuffer[0] = 0;
    mLength = 0;
  }
}

void StringBuffer::timestamp()
{
#ifdef WIN32
  SYSTEMTIME st;
  GetSystemTime(&st);
  sprintf(mTimestamp, "%4d-%02d-%02dT%02d:%02d:%02d.%04d", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
#else
  struct timeval tv;
  struct timezone tz;
 
  gettimeofday(&tv, &tz);
 
  strftime(mTimestamp, 64, "%Y-%m-%dT%H:%M:%S", gmtime(&tv.tv_sec));
  sprintf(mTimestamp + strlen(mTimestamp), ".%06d", tv.tv_usec);
#endif
}

---

Associated header String_Buffer.hpp

Code:

---

#ifndef STRING_BUFFER_HPP
#define STRING_BUFFER_HPP

/*
 * A simple extensible string that can be appended to. The memory will be reused
 * since it maintains its length. The string buffer also supports setting a timestamp
 * that will be prepended to the string once some data is appended.
 *
 * Currently allocating in 1k increments.
 */
class StringBuffer
{
protected:
  char *mBuffer; /* A resizable character buffer */
  size_t mSize;    /* The allocated size of the string */
  size_t mLength;  /* The length of the string */
  char mTimestamp[64];
 
public:
  StringBuffer(const char *aString = 0);
  ~StringBuffer();

  operator const char *() { return mBuffer; }
  const char *append(const char *aString);
  const char* operator<<(const char *aString) { return append(aString); }
  void reset();
  void timestamp();
  size_t  length() { return mLength; }
};

#endif

---

Any ideas? It seems fine to me, but I honestly do not know.

Ah, they wrote they're own string class - priceless.

Check where mDevice has been set. Look at the variable and make sure it isn't truncated. If it is, find out why it gets truncated.

Serial.hpp

Code:

---

#ifndef SERIAL_HPP
#define SERIAL_HPP

class Serial {
public:
  class SerialError
  {
  private:
    char mMessage[1024];

  public:
    SerialError(const char *aMessage);
    const char *message() const { return mMessage; }
  };
private:

 
protected:
  /* Descriptor (tty or socket) */
#ifdef WIN32
  HANDLE mFd;
#else
  int mFd;
#endif
 
  /* Flag debug */
  bool mDebug;
 
  /* TCP port */
  int mPort;
 
  /* Device: "/dev/ttyS0", "/dev/ttyUSB0" or "/dev/tty.USA19*"
    on Mac OS X for KeySpan USB<->Serial adapters this string
    had to be made bigger on OS X as the directory+file name
    was bigger than 19 bytes. Making it 67 bytes for now, but
    OS X does support 256 byte file names. May become a problem
    in the future. */
 
#ifdef __APPLE_CC__
  char mDevice[64];
#else
  char mDevice[16];
#endif
 
  /* Bauds: 9600, 19200, 57600, 115200, etc */
  int mBaud;
 
  /* Data bit */
  unsigned char mDataBit;
 
  /* Stop bit */
  unsigned char mStopBit;
 
  /* Parity: "even", "odd", "none" */
  char mParity[5];
 
  /* In error_treat with TCP, do a reconnect or just dump the error */
  bool mErrorHandling;
 
  /* IP address */
  char mIp[16];
 
#ifndef WIN32
  /* Save old termios settings */
  struct termios mOldTios;
#endif

  bool mConnected;

private:
  int read(char *aBuffer, int len);
  int write(const char *aBuffer, int len);

public:
  Serial(const char *aDevice,
        int aBaud, const char *aParity, int aDataBit,
        int aStopBit, bool aDebug = false);
  ~Serial();

  bool debug() { return mDebug; }
  bool connected() { return mConnected; }

  bool connect();
  bool disconnect();
  int  readUntil(const char *aUntil, char *aBuffer, int aLength);
  int  write(char *aBuffer);
  bool flushInput();
};

#endif

---

Serial.cpp

Code:

---


#include "internal.hpp"
#include "serial.hpp"
#include <windows.h>
#include <strsafe.h>

Serial::SerialError::SerialError(const char *aMessage)
{
  strncpy(mMessage, aMessage, 1023);
  mMessage[1023] = '\0';
}

Serial::Serial(const char *aDevice,
              int aBaud, const char *aParity, int aDataBit,
              int aStopBit, bool aDebug)
{
  mBaud = aBaud;
  strncpy(mDevice, aDevice, sizeof(mDevice) - 1);
  mParity[sizeof(mDevice) - 1] = '\0';
  strncpy(mParity, aParity, sizeof(mParity) - 1);
  mParity[sizeof(mParity) - 1] = '\0';
  mDataBit = aDataBit;
  mStopBit = aStopBit;
  mDebug = aDebug;

#ifdef WIN32
  mFd = INVALID_HANDLE_VALUE;
#else
  mFd = -1;
#endif
  mConnected = false;
}
 
Serial::~Serial()
{
  disconnect();
}

int Serial::readUntil(const char *aUntil, char *aBuffer, int aLength)
{
  if (!mConnected)
  {
    printf("Trying to read when not connected");
    return -1;
  }
   
  if (mDebug)
    printf("Reading upto &#37;d bytes or we get a match\n", aLength, aUntil);

  int len = 0, count = 0;
  char *cp = aBuffer;
  const char *match = aUntil;
  do
  {
    int ret = read(cp, 1);
    if (ret == -1)
    {
      throw SerialError("Couldn't read");
    }
    if (ret == 0)
    {
      usleep(10 * 1000); // 10 msec
      if (count++ > 100)
      {
        printf("Read timed out\n");
        return -1;
      }
    }
    else
    {
      count = 0;
     
      //printf("Received: %d == match: %d\n", *cp, *match);
      if (*match == *cp)
        match++;
      else
        match = aUntil;

      // See if we can match the beginnig of the string again.
      if (*match == *cp)
        match++;
      //printf("Match now: %d\n", *match);
      cp++;
      len++;
    }
  } while (len <= aLength && *match != '\0');

  *cp = '\0';

  if (mDebug)
    printf("Read returned: %d - '%s'\n", len, aBuffer);

  return len;
}

int Serial::write(char *aBuffer)
{
  if (mDebug)
    printf("Writing '%s'\n", aBuffer);

  int ret = write(aBuffer, (int) strlen(aBuffer));
  if (ret < 0)
    throw SerialError("Couldn't write");
 
  if (mDebug)
    printf("Write returned: %d\n", ret);
 
  return ret;
}

bool Serial::flushInput()
{
  char buffer[2];
  int ret;
  do
  {
    ret = read(buffer, 1);
    if (ret < 0)
      throw SerialError("Couldn't read");
  } while (ret > 0);

  return true;
}

#ifdef WIN32
#include "serial.win32.cpp"
#else
#include "serial.unix.cpp"
#endif

---

Is this what you were looking for? Is that setting mDevice, its hard for me to understand it to be honest

What is mDevice declared as? How big is that array? Is it big enough to fit all of these characters? I see it is declared as an array of 64 (or 16) characters. What if there are more characters? What do you do then?

In general, your code is very faulty, as it does no checking if there is enough room for all of those strings. It is a classic example of how a buffer can be overrun, and therefore exploited by hackers.

Basically, you have a 'C' program, not a C++ program. Yes, you have some C++ syntax thrown in here and there, but it is basically a 'C' program. It does not use anything of C++ in terms of safety (buffer overruns).

Regards,

Paul McKenzie

If you are using a version of Visual C++ that hasn't been written 2 decades ago (i.e. not VC6), just right click on mDevice and choose "Go to declaration".

Here is where the declaration is. So 16 characters.

Code:

---

#ifdef __APPLE_CC__
  char mDevice[64];
#else
  char mDevice[16];
#endif

---

Quote:

---

Originally Posted by wklove2003

Here is where the declaration is. So 16 characters.

Code:

---

#ifdef __APPLE_CC__
  char mDevice[64];
#else
  char mDevice[16];
#endif

---

---

What if the name is more than 16 characters? How are you going to stuff 10 pounds of potatos into a 5 pound bag?

Code:

---

strncpy(mDevice, aDevice, sizeof(mDevice) - 1);

---

This effectively truncates that name to 15 characters.

Code:

---

CreateFile on \\.\C:\Documents an=failed with error code: 2"

---

That is the message you got back. Look at the name -- it should be much more than 15 characters. How much more? That's what string classes such as CString and std::string are for -- unlimited length strings.

Regards,

Paul McKenzie

For example, this is the StringBuffer code, simplified.

Code:

---

#ifndef STRING_BUFFER_HPP
#define STRING_BUFFER_HPP

#include <string>

class StringBuffer
{
protected:
  std::string mBuffer; /* A resizable character buffer */
  char mTimestamp[64];
 
public:
  StringBuffer(const char *aString = 0);

  operator const char *() { return m_Buffer.c_str(); }
  const char *append(const char *aString)
  const char* operator<<(const char *aString) { return append(aString); }
  void reset();
  void timestamp();
  size_t  length() { m_Buffer.size(); }
};

#endif

---

Code:

---

#include "internal.hpp"
#include "string_buffer.hpp"

StringBuffer::StringBuffer(const char *aString)
{
    if ( aString )
          m_Buffer = aString;
}

const char *StringBuffer::append(const char* aString)
{
      m_Buffer += mTimestamp;
      m_Buffer += aString;
      return mBuffer.c_str() ;
}

void StringBuffer::reset()
{
    m_Buffer.clear();
}

void StringBuffer::timestamp()
{
#ifdef WIN32
  SYSTEMTIME st;
  GetSystemTime(&st);
  sprintf(mTimestamp, "%4d-%02d-%02dT%02d:%02d:%02d.%04d", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
#else
  struct timeval tv;
  struct timezone tz;
 
  gettimeofday(&tv, &tz);
 
  strftime(mTimestamp, 64, "%Y-%m-%dT%H:%M:%S", gmtime(&tv.tv_sec));
  sprintf(mTimestamp + strlen(mTimestamp), ".%06d", tv.tv_usec);
#endif
}

---

Regards,

Paul McKenzie