Writing unicode to file

[yeah1000]

Hi, i have some data in a buffer that i need to write to a file: writing: for(unsigned int i = 4; i<(nReceivedBytes-2); i++) { //_tprintf(_T("%c"), DataBuf.buf[i]); myfile.open ("file.doc", ios::out | ios::app); myfile<<(DataBuf.buf[i]); myfile.close(); } The data is in unicode (2 bytes), the first four bytes show the length of the data package and the last two are zero. The file wont open with openoffice and when i open it with notepad++ it displays some characters but most of them are NUL. What could be the problem? Thank you

[Nuri Ismail]

yeah1000 wrote:

myfile.open ("file.doc", ios::out | ios::app);

What is the type of myfile object - std::ofstream or std::wofstream? When you write unicode data you should use std::wofstream.

Nuri Ismail

[yeah1000]

It was ofstream, i changed it to "wofstream myfile;" but it did't help :( The data arrives over TCP, using WSABUF which i understand is actually of type char. Should i be able to write the data to file two bytes at a time so it could be opened?

[Naveen]

yeah1000 wrote:

The file wont open with openoffice and when i open it with notepad++ it displays some characters but most of them are NUL. What could be the problem?

For application to know that your file is a unicode one, the first two bytes of the file needs to be 0xff and 0xfe. If the first two bytes doesn't indicates any of the encoding codes, it will consider the file and ASCII file. I guess thats what happend in your case. Check http://en.wikipedia.org/wiki/Byte-order_mark[^] for more details.

nave [OpenedFileFinder] [My Blog]

[yeah1000]

Openoffice sometimes gives me the choice to choose in which format the file is, but when i select unicode then the file still is unreadable. Is there no way to write the file in binary format (as with binarywriter in c# for example) so that it wouldnt matter in which format it is?

[David Crow]

Unicode aside, the only data that is going to exist in your file is DataBuf.buf[last_value_of_i]. You should probably be opening and closing the file outside of the for() loop.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

[Naveen]

yeah1000 wrote:

(as with binarywriter in c# for example)

What difference does the file have when a string is written in c# using binary mode and in non binary mode?

nave [OpenedFileFinder] [My Blog]

[yeah1000]

Filemode is append, it does not help if i place it outside of the for cycle.

[David Crow]

yeah1000 wrote:

Filemode is append...

My bad. I overlooked that piece.

yeah1000 wrote:

...it does not help if i place it outside of the for cycle.

On the contrary, file I/O is very expensive (compared to reading from or writing to the file). If you are only writing a handful of bytes to the file, however, indeed it will never be noticed. For larger files, it's just plain wrong.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

[yeah1000]

I am aware of that, i actually open and close the file far outside of the cycle, when i copied part of the code here i changed it to that. However, at the moment the problem is elsewhere. Is it not necessary to define it somehow that i am using tchar? The buffer is in char format, if i write it to file byte by byte, at the end it should not matter that one char is actually 2 bytes in length, assuming that openoffice realizes that it is in unicode format?

[David Crow]

yeah1000 wrote:

However, at the moment the problem is elsewhere.

True, which is why I prefaced my initial comment as such.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons