How to open a file using _TCHAR* as a file name? c/c++

Question

My main has the following signature:

int _tmain(int argc, _TCHAR* argv[])

I would like to preform the following:

FILE *inputFilePtr;
inputFilePtr = fopen(argv[2], "_r");

But there is a type mismatch. How should I do it? Should I use:

inputFilePtr = _tfopen(argv[2], ??????);

Thanks!

The tchar.h header is non-standard and archaic. There's no point in using it anymore, there are no non-Unicode versions of Windows left. Use the wide versions today, _wfopen() and the L prefix on string literals. — Hans Passant, Mar 19 '11 at 17:13

score 7 · Answer 1 · answered Mar 19 '11 at 17:04

7

Use:

_tfopen(argv[2], TEXT("r"));

Do not use:

_tfopen(argv[2], L"r");

The second one will give compilation error if the macro UNICODE is not defined, that is, when TCHAR is just char, not wchar_t.

answered Mar 19 '11 at 17:04

Nawaz

Mihran Hovsepyan · Answer 2 · 2011-03-19T17:07:46.213

0

Use _tfopen(argv[2], TEXT("r"));

or _tfopen(argv[2], L"r"); if TCHAR is WCHAR.

edited Mar 19 '11 at 17:07

answered Mar 19 '11 at 17:00

Mihran Hovsepyan

2

Second one is not so correct. What if `TCHAR` is just `char`? `L"r"` always makes `wchar_t`, as far as I know! – Nawaz Mar 19 '11 at 17:02
You Are right @Nawaz, but in most cases TCHAR is WCHAR and this code will work. Otherwise it will give compile error and will be corrected easily. – Mihran Hovsepyan Mar 19 '11 at 17:04
@Mihran: As I said, what if `TCHAR` is `char`? Your code will fail! – Nawaz Mar 19 '11 at 17:05
@Mihran: Yes. That is what I'm saying : the second one is not correct! – Nawaz Mar 19 '11 at 17:08
Consistency is important, use _wfopen() instead of relying on compiler errors. It is not you that gets it wrong, it is somebody else that will be flummoxed about you writing the code this way. – Hans Passant Mar 19 '11 at 17:09
Don't be so pedantic @Nawaz ))) I changed it to be more clear. – Mihran Hovsepyan Mar 19 '11 at 17:10
3

@Mihran: Pedanticism has nothing to do with it. You should write your code so that it functions in both cases. – Lightness Races in Orbit Mar 19 '11 at 17:22

2 Answers2