String to byte conversion

Question

I am working on Visual studio C++.

I have these codes:

    CString str; 
    BYTE byBuffer[10000] = { 0 };
    str ="Invalid Command. Spaces are not allowed too!!";
    strcpy_s(reinterpret_cast<LPSTR>(byBuffer), 10000, T2CA(str ));

The problem is byBuffer = "Invalid Command. Spaces are not allowed too!!"; but after the following line, the string changes. LPBYTE lp=byBuffer ; Although it works fine for small strings like OK, GOOD JOB. etc..

i am debugging the whole code by setting the breakpoints. moreover this function has been called to another function in which ( LPBYTE lpBuffer) recieved this value.

Plz help

In what manner is it not working. what kind of output are you getting? — Sam I am says Reinstate Monica, Sep 12 '12 at 17:18
Can you please make a small compilable version of the code? What is the T2CA macro definition? — UnknownGosu, Sep 12 '12 at 17:18
only first three characters and den garbage value like : Inv@@@@@@@@@@@ — Nabeel, Sep 12 '12 at 17:20
@UnknownGosu, [T2CA](http://msdn.microsoft.com/en-us/library/87zae4a3(v=vs.80).aspx) is from Microsoft. — Mark Ransom, Sep 12 '12 at 17:22
What is the reason you don't just write `strcpy_s(reinterpret_cast(byBuffer), 10000, "Invalid Command. Spaces are not allowed too!!");`? — john, Sep 12 '12 at 17:24
@SamIam; can you please highlight the mistake by writing exact line. thanks — Nabeel, Sep 12 '12 at 17:25
How are you verifying the contents of `byBuffer` at the end? Perhaps the buffer contains the right stuff but you just don't know it. — Mark Ransom, Sep 12 '12 at 17:25
Maybe it will help you: http://stackoverflow.com/questions/1650035/how-to-convert-cstring-to-bytes — FacundoGFlores, Sep 12 '12 at 17:27
i edited my question- plz have a look again- byBuffer contains that exact string but not lp — Nabeel, Sep 12 '12 at 17:39

score 2 · Accepted Answer · answered Sep 12 '12 at 18:09

The code you're showing us looks OK, so I'm going out on a limb and making a guess.

I'm guessing that you're trying to return this buffer from a function:

LPBYTE lp = byBuffer;
return lp;

If that's the case, then the local variable byBuffer is getting destroyed at the end of the function and the pointer no longer points to valid memory. You're lucky if you can see anything recognizable in the output at all.

String to byte conversion

1 Answers1