Trouble using ReadFile() to read a string from a text file - c++

Question

How can I make the code below to read correct text. In my text file has Hello welcome to C++, however at the end of the text, it has a new line. With the code below, my readBuffer always contains extra characters.
DWORD byteWritten;
int fileSize = 0;
//Use CreateFile to check if the file exists or not.
HANDLE hFile = CreateFile(myFile, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if(hFile != INVALID_HANDLE_VALUE)
{
BOOL readSuccess;
DWORD byteReading;
char readBuffer[256];
readSuccess = ReadFile(hFile, readBuffer, byteReading, &byteReading, NULL);
if(readSuccess == TRUE)
{
TCHAR myBuffer[256];
mbstowcs(myBuffer, readBuffer, 256);
if(_tcscmp(myBuffer, TEXT("Hello welcome to C++")) == 0)
{
FindClose(hFile);
CloseHandle(hFile);
WriteResultFile(TRUE, TEXT("success!"));
}
}
}
Thanks,

Answer 1

There are a few problems:
You're passing uninitialized data (byteReading) as the "# of bytes to read" parameter to ReadFile().
Depending on how you created the file, the file's contents may not have a terminating 0 byte. The code assumes that the terminator is present.
FindClose(hFile) doesn't make sense. CloseHandle(hFile) is all you need.
You need to call CloseHandle if CreateFile() succeeds. Currently, you call it only if you find the string you're looking for.
This isn't a bug, but it's helpful to zero-initialize your buffers. That makes it easier to see in the debugger exactly how much data is being read.

Answer 2

HANDLE hFile = CreateFile(myfile, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if(hFile != INVALID_HANDLE_VALUE)
{
BOOL readSuccess;
DWORD byteReading = 255;
char readBuffer[256];
readSuccess = ReadFile(hFile, readBuffer, byteReading, &byteReading, NULL);
readBuffer[byteReading] = 0;
if(readSuccess == TRUE)
{
TCHAR myBuffer[256];
mbstowcs(myBuffer, readBuffer, 256);
if(_tcscmp(myBuffer, TEXT("Hello welcome to C++")) == 0)
{
rv = 0;
}
}
CloseHandle(hFile);
}
I see two things:
byteReading isn't initialized
you are reading bytes so you have to terminate the string by 0.
CloseHandle is sufficient

Answer 3

Either remove the new line character from the file or use _tcsstr for checking the existence of the string "Hello Welcome to C++".