Hi.. When I use the win32 file I/O function to output text(using WriteFile), the newline const (\n) gets displayed as a square block (in the text file) instead of moving to a new line. Anyone knows how to make it write a new line instead of the block?? Thanks..

Try using \r\n instead of just \n. (Or it might be \n\r, but I''m pretty sure it''s one of the two.) DOS text files like have a carriage return-new line pair instead of just a new line character. It''s a legacy from the days of teletype output.

A better solution is to just use the standard I/O functions (ie streams) if you''re doing text files. That way, the native line termination characters are automatically used when you use std::endl.

-Brian

Sometimes you need to use the API functions. It''s still important to know in the (admittedly contrived) case of writing a text file to a remote resource. ex: \\othercomputer\textfile.txt. Last I checked the file iostreams weren''t too happy about Windows style remote resources. (you can''t specify necessary security parameters.)

I see..thanks

I''m using the _crtMem debug library to test for memory leaks and the output file must take a HFILE handle (one created by CreateFile) rather than a FILE pointer (C file stream)

but with the HFILE pointer, the supposingly newlines are converted to square characters and everything is in 1 one line, even the output from the library.

Any idea plz.

I never had that problem before -- first time I tried it, my strings were being written on separate lines, and I viewed the file in Notepad. I think it might have been because I was writing the terminating NULL character ''\0''? It''s a "hidden" character at the end of a character array (string) that many C functions use. It could also be the program you are using to view it. I really don''t know much about this though -- just an idea.


Sabre Multimedia
- null_pointer

They''re not being converted as such. Those square characters are your newlines. Notepad just displays them that way to show that there is something there. The newline in C \n is not sufficient for DOS/WINDOWS apps which often need \r\n (or \n\r, they seem to function equivalently) to recognise a newline. Unix machines just use the \n, and I am not at all sure but I think Macs just use \r. So you may have to write a parsing routine which takes your \n and converts it to \r\n in the output.

null_pointer:

Interesting. I use Notepad to view the files too but there are all square blocks..

May I know how you created the file handle?? I use the windoz function CreateFile

I have tried this and \r is enough to give a newline. \n always give a square block, even with \r\n

Oops! it wasn''t Notepad -- it was MSVC''s text file viewer. You could do something like the following to make your code more readable, though:


const char LineReturn[3] = "\r\n";

// start on line 3
WriteFile(hFile, LineReturn, sizeof(char) * 2);
WriteFile(hFile, LineReturn, sizeof(char) * 2);

// write some more data
WriteFile(hFile, MapArray, 500);

// end the line
WriteFile(hFile, LineReturn, sizeof(char) * 2);

// continue writing more data...



I think that''s right -- the parameters might be a little mixed up because I haven''t used it in a while. I think \r and \n are counted as 1 character each. If not, you''ll have to adjust LineReturn[] and the WriteFile statements that use it.

Good Luck!




- null_pointer
Sabre Multimedia

The sad thing is it''s not my functions that are writing to the file.

It''s the VC++ version of C debug library functions (the _CrtMemory checking functions) that is spitting out the text, and I can''t find a way to make WriteFile spit out the correct newline character.

Guess I have to post process the file..8(..