char[4] to char[40]

[lucki_luke]

Hey all,

im having this problem here (kind of n00b problem):

i have a struct as follows:

typedef struct 
{ 
	TCHAR strName[40]; 
	TCHAR strPath[64]; 
    bool bStarted;
} Program;

and im trying to read a file that contains infos to put that into

Program X[50];

later on.

now when im reading the file and trying to put the name specified in the file, like "asd", into the X program im always getting the error that i cant convert char[4] to char[40].

X[i].strName = "asd";

Any help is appreciated.

thx

[CornedBee]

You need to use strcpy. You also need to properly honour the fact that you're using TCHAR and wrap the string literal with TEXT(), like this: TEXT("asd"). You also should not use a type that's dependent on a compilation flag, such as TCHAR, for data stored in a file - one version of the program would be unable to read files generated by the other!
Instead you should use WCHAR or wchar_t and convert to a different character set manually in ANSI versions of the program - use WideCharToMultiByte() for that.

[lucki_luke]

ok thx for the quick reply gonna try that

[MadCow257]

another option is TCHAR * strName or String since this is c++

[CornedBee]

TCHAR* will cause memory troubles (you have to allocate a buffer and remember to deallocate it.)
Both will not work if the Program struct is supposed to be written directly to the file using fwrite/ostream::write.

[lucki_luke]

using WCHAR works now with using strcpy and a reinterpret_cast to convert the WCHAR array to a char *

strcpy(reinterpret_cast<char *>(X[i].strPath), ((*(vIter2)).substr((*(vIter2)).find("=") + 1)).c_str());

thx again

[cboard_member]

What is all this TCHAR bull anyhow? What's wrong with good ol' char* / char[] ? (Ok so I know what's wrong, but meh ). Let me guess, TCHAR is an MSVC specific re-def type thingy around char buffers? Eww.

[jwenting]

well, it's actually from the platform SDK, not the compiler library...

from WTypes.h:

typedef wchar_t WCHAR;

typedef WCHAR TCHAR;

So a WCHAR is a TCHAR is a wchar_t, I guess someone just liked his capitals
Of course these tricks save quite some work when moving from a 16 bit to a 32 bit environment, all you now need to do is change the typedef in one header file and recompile, instead of changing potentially hundreds of thousands of declarations.

[CornedBee]

well, it's actually from the platform SDK, not the compiler library...

from WTypes.h:

typedef wchar_t WCHAR;

typedef WCHAR TCHAR;

So a WCHAR is a TCHAR is a wchar_t.

Wrong. If you care to take a closer look, you'll find that if the UNICODE macro is not defined, either WTypes.h isn't even included or TCHAR is a typedef for CHAR, which is a typedef for char.
In addition, you'll find that

const wchar_t *ptr = "hello";

doesn't compile, so if WCHAR == TCHAR, then the code wouldn't compile.

And DON'T DON'T DON'T use wchar_t/char reinterpret_casts!!! You'll get nonsensical data.

[homeyg]

Yes the whole point of TCHAR is so if you have #define UNICODE, TCHAR will be a typedef for wchar_t (and the TEXT() macro will place the L prefix on strings enclosed in the macro) and if UNICODE is not defined, TCHAR will be a typedef for char (and the TEXT() macro will do nothing).

#ifdef UNICODE

#define __TEXT(q) L##q
#else
#define __TEXT(q) q
#endif

#define TEXT(q) __TEXT(q)

That's straight from winnt.h.