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#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "windows.h"
#define BIGREAD 256000
unsigned char readbuff[BIGREAD];
int __cdecl main(int argc,char *argv[]) {
HANDLE hFile; DCB MyDcb; char *MyPort = "COM1"; DWORD NumberActuallyRead; DWORD NumberToRead = 0; DWORD UseBaud = 19200; COMMTIMEOUTS To; COMMPROP MyCommProp; DWORD numberReadSoFar; DWORD TotalCount; DWORD j;
if (argc > 1) {
sscanf(argv[1],"%d",&NumberToRead);
if (argc > 2) {
sscanf(argv[2],"%d",&UseBaud);
if (argc > 3) {
MyPort = argv[3];
}
}
}
printf("Will try to read %d characters.\n",NumberToRead); printf("Will try to read a %d baud.\n",UseBaud); printf("Using port %s\n",MyPort);
if ((hFile = CreateFile( MyPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL )) == ((HANDLE)-1)) {
printf("Couldn't open the port - last error is: %d\n",GetLastError()); exit(1);
}
printf("We successfully opened the %s port.\n",MyPort);
To.ReadIntervalTimeout = 0; To.ReadTotalTimeoutMultiplier = ((1000+(((UseBaud+9)/10)-1))/((UseBaud+9)/10)); if (!To.ReadTotalTimeoutMultiplier) { To.ReadTotalTimeoutMultiplier = 1; } printf("Multiplier is: %d\n",To.ReadTotalTimeoutMultiplier); To.ReadTotalTimeoutConstant = 5000; To.WriteTotalTimeoutMultiplier = 0; To.WriteTotalTimeoutConstant = 5000;
if (!SetCommTimeouts( hFile, &To )) {
printf("Couldn't set the timeouts - last error: %d\n",GetLastError()); exit(1);
}
//
// We've successfully opened the file. Set the state of
// the comm device. First we get the old values and
// adjust to our own.
//
if (!GetCommState( hFile, &MyDcb )) {
printf("Couldn't get the comm state: %d\n",GetLastError()); exit(1);
}
if (!GetCommProperties( hFile, &MyCommProp )) {
printf("Couldn't get the comm prop: %d\n",GetLastError()); exit(1);
}
//
// Set the Xoff/xon limit so that it lowers the handshake
// whenever we have more than 50 chars in our buffer,
// and raises when we drop below 20.
//
MyDcb.XoffLim = MyCommProp.dwCurrentRxQueue - 50; MyDcb.XonLim = 20;
MyDcb.BaudRate = UseBaud; MyDcb.ByteSize = 8; MyDcb.Parity = NOPARITY; MyDcb.StopBits = ONESTOPBIT;
//
// Make sure that the only flow control is input RTS.
//
MyDcb.fOutxDsrFlow = FALSE; MyDcb.fOutxCtsFlow = FALSE; MyDcb.fDsrSensitivity = FALSE; MyDcb.fOutX = FALSE; MyDcb.fInX = FALSE; MyDcb.fDtrControl = DTR_CONTROL_DISABLE; MyDcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
if (!SetCommState( hFile, &MyDcb )) {
printf("Couldn't set the comm state - last error: %d\n",GetLastError()); exit(1);
}
//
// Read ten chars at a time until we get all the
// chars or we get some kind of error.
// We delay 100ms after each read to let the buffer
// have a chance to fill up some.
//
for ( numberReadSoFar = 0; numberReadSoFar < NumberToRead;
) {
if (ReadFile( hFile, &readbuff[numberReadSoFar], 10, &NumberActuallyRead, NULL )) {
//
// If there was no characters (timed out), then
// we probably won't see anything.
//
if (!NumberActuallyRead) {
printf("No chars - Timeout!\n"); break;
} numberReadSoFar += NumberActuallyRead; Sleep(100);
continue;
} else {
//
// Some kind of read error.
//
DWORD LastError; LastError = GetLastError(); printf("Couldn't read the %s device.\n",MyPort); printf("Status of failed read is: %d\n",LastError);
//
// Get the error word from clear comm error.
//
if (!ClearCommError( hFile, &LastError, NULL )) {
printf("Couldn't call clear comm error: %d\n",GetLastError()); exit(1);
} else {
if (!LastError) {
printf("No LastError\n");
} else {
if (LastError & CE_RXOVER) {
printf("Error: CE_RXOVER\n");
}
if (LastError & CE_OVERRUN) {
printf("Error: CE_OVERRUN\n");
}
if (LastError & CE_RXPARITY) {
printf("Error: CE_RXPARITY\n");
}
if (LastError & CE_FRAME) {
printf("Error: CE_FRAME\n");
}
if (LastError & CE_BREAK) {
printf("Error: CE_BREAK\n");
} if (LastError & ~(CE_RXOVER | CE_OVERRUN | CE_RXPARITY | CE_FRAME | CE_BREAK)) {
printf("Unknown errors: %x\n",LastError);
}
}
} exit(1);
}
}
for ( TotalCount = 0; TotalCount < numberReadSoFar; ) {
for ( j = 0; j <= 9; j++ ) {
if (readbuff[TotalCount] != j) {
printf("Bad data starting at: %d\n",TotalCount); goto donewithcheck;
}
TotalCount++; if (TotalCount >= numberReadSoFar) {
break;
}
}
}
donewithcheck:;
exit(1);
}
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