r/w binary

[Ali Çehreli]

On Thu, 30 Jun 2011 15:52:59 +1200, Joel Christensen wrote:

> I'm thinking more about handling binary files. With the C version I
> would write a int for how many letters in the string, then put in the
> the string along side ([0005][house]). That way I can have any character
> at all (though I just thinking of char's).

I would still use a portable text format myself.

For binary, you should consider rawWrite() and rawRead(). Here is just a 
start:

import std.stdio;

void main()
{
    int i = 42;
    auto file = File("deleteme.bin", "w");
    file.rawWrite((&i)[0..1]);
}

(Aside: The 'b' for binary mode does nothing in POSIX systems; so it's 
not necessary.)

The parameter to rawWrite() above is a nice feature of D: slicing a raw 
pointer produces a safe slice:

  http://digitalmars.com/d/2.0/arrays.html

<quote>
Slicing is not only handy for referring to parts of other arrays, but for 
converting pointers into bounds-checked arrays:

int* p;
int[] b = p[0..8];
</quote>

For strings (actually arrays), you would need .length and .ptr properties.

I've never used it but you might want to consider the serialization 
library Orange as well:

  http://www.dsource.org/projects/orange

Ali