CODEWITHSUNDEEP
c++winapiserial-portreadfile
armandfp
armandfp

Reputation: 1069

ReadFile, COM and NULL characters in c++

I have a problem with ReadFile function in a virtual serial port:

char tmp[128];
int multiplo=0;
DWORD err;
COMSTAT stt;

ClearCommError(hcom, &err, &stt);
do{
    if(ReadFile(hcom, tmp, stt.cbInQue, &err, NULL)){
        tmp[err] = '\0';
        memcpy(bfIn+multiplo, tmp, err);
        multiplo = multiplo + err;
    }else
        return 0;
}while(err > 0);

this code works when ReadFile get valid character like 0x01, 0x02, 0x03... but there is a problem with 0x00, the code doesn't read like I expected, I try with hyperterminal and that works perfect.

I've defined in dcb structure:

dcb.fNull = false;

but still I have the same problem, any help?

Upvotes: 1

Views: 1128

Answers (1)

Android Eve
Android Eve

Reputation: 14964

The problem seems to be not in ReadFile() but rather in your use of tmp[] as the terminating '\0' happens to be 0x00, too.

What do you mean by "doesn't read like I expected"? Can you describe the symptoms in more detail?

Upvotes: 0

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