Writing binary data

[masterlodi]

I need to write data to a binary file.

Integers and strings I'm fine with. But how can I write a float as binary data?

 

[xwb]

float bouy;
FILE* xxx;
...
fwrite (&bouy, 1, sizeof (bouy), xxx);

 

[masterlodi]

Due to the nature of the program, I'm writing this to a buffer first and then using WriteFile, so I can't use this method. I'm using VS 2005.

 

[Salem]

Copy it to your buffer using memcpy() then.


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[masterlodi]

I currently have a UCHAR array that I'm 'sprintf'ing too. I'm then writing the array to a newly created file!

 

[Miros]

Then it's a text file, not a binary file.

I think this is what the previous poster meant:

float bouy ;
UCHAR ocean[bignumber] ;

memcpy( &bouy, ocean + amt, sizeof( bouy ) ) ;
amt += sizeof( bouy ) ;

 

[masterlodi]

The file I am writing to as a binary file, not a text file.

 

[Salem]

You could actually post some real code rather than just posting one-line counter arguments to everything which is being suggested.


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[Miros]

Ok, let's talk definitions...

A binary file contains the raw data. So if you're writing long integers containing 1,2,3,4,5, your sequence of bytes will be

0x1,0x0,0x0,0x0,0x2,0x0,0x0,0x0,0x3,0x0,0x0,0x0,0x4,0x0,0x0,0x0,0x5,0x0,0x0,0x0

Is this what you want?

Or do you want "1,2,3,4,5"? That's called either a Text file or an ASCII file, not binary.

 

[masterlodi]

I'm sorry there has been some confusion here - I am not not writing to a text file, I am writing integers as binary data.

float fVal;
UCHAR uFileImage[964];

memcpy(&fVal, uFileImage + fOffset, sizeof(float));

This code fragment solves my problem. Thanks everyone.