• solidstate1991 (6/6) Jul 21 2017 Due to it's convenience, I was thinking on reading and writing
• Mike Parker (22/28) Jul 21 2017 struct Data {
• Mike Parker (9/37) Jul 21 2017 I should add, though, that you're better off using either
• solidstate1991 (4/13) Jul 22 2017 Well, it seems the toStringz() function adds a few garbage
• Adam D. Ruppe (5/7) Jul 22 2017 How are you using it? The only character it should be adding is
• Temtaime (5/5) Jul 23 2017 Hi !

solidstate1991 <laszloszeremi outlook.com> writes:

Due to it's convenience, I was thinking on reading and writing 
file headers by creating structs mirroring the layouts of actual 
headers I would need. I've seen many examples of this in C, 
however I' struggling using the same methods through the use of 
code.stdc.stdio, especially as I can't really trace bugs from 
fread.

Mike Parker <aldacron gmail.com> writes:

On Saturday, 22 July 2017 at 01:45:29 UTC, solidstate1991 wrote:
 Due to it's convenience, I was thinking on reading and writing 
 file headers by creating structs mirroring the layouts of 
 actual headers I would need. I've seen many examples of this in 
 C, however I' struggling using the same methods through the use 
 of code.stdc.stdio, especially as I can't really trace bugs 
 from fread.

struct Data {
     int x;
     float y;
     ubyte z;
}

void main() {
     import core.stdc.stdio;

     Data od = Data(10, 3.0f, 5);

     FILE* fp = fopen("data.dat", "wb");
     size_t ret = fwrite(&od, od.sizeof, 1, fp);
     fclose(fp);

     assert(ret == 1);

     Data id;
     fp = fopen("data.dat", "rb");
     ret = fread(&id, id.sizeof, 1, fp);
     fclose(fp);

     assert(ret == 1);

     assert(id.x == 10);
     assert(id.y == 3.0f);
     assert(id.z == 5);
}

Mike Parker <aldacron gmail.com> writes:

On Saturday, 22 July 2017 at 02:11:27 UTC, Mike Parker wrote:
 On Saturday, 22 July 2017 at 01:45:29 UTC, solidstate1991 wrote:
 Due to it's convenience, I was thinking on reading and writing 
 file headers by creating structs mirroring the layouts of 
 actual headers I would need. I've seen many examples of this 
 in C, however I' struggling using the same methods through the 
 use of code.stdc.stdio, especially as I can't really trace 
 bugs from fread.

 struct Data {
     int x;
     float y;
     ubyte z;
 }

 void main() {
     import core.stdc.stdio;

     Data od = Data(10, 3.0f, 5);

     FILE* fp = fopen("data.dat", "wb");
     size_t ret = fwrite(&od, od.sizeof, 1, fp);
     fclose(fp);

     assert(ret == 1);

     Data id;
     fp = fopen("data.dat", "rb");
     ret = fread(&id, id.sizeof, 1, fp);
     fclose(fp);

     assert(ret == 1);

     assert(id.x == 10);
     assert(id.y == 3.0f);
     assert(id.z == 5);
 }

I should add, though, that you're better off using either 
std.stdio.File or std.file. Use the former if you need to make 
multiple reads/writes to a file, the latter if you can pull it in 
or push it out all in one go. They take arrays as arguments, so 
if you have something like Data[], you can pass it directly to 
the appropriate functions. To write a single instance, you'll 
have to take the pointer and slice it. Either way, it's less 
code, less error prone, and more idiomatic than using the C API.

solidstate1991 <laszloszeremi outlook.com> writes:

On Saturday, 22 July 2017 at 02:22:53 UTC, Mike Parker wrote:
 I should add, though, that you're better off using either 
 std.stdio.File or std.file. Use the former if you need to make 
 multiple reads/writes to a file, the latter if you can pull it 
 in or push it out all in one go. They take arrays as arguments, 
 so if you have something like Data[], you can pass it directly 
 to the appropriate functions. To write a single instance, 
 you'll have to take the pointer and slice it. Either way, it's 
 less code, less error prone, and more idiomatic than using the 
 C API.

Well, it seems the toStringz() function adds a few garbage 
characters to the end of the filename, I might look into a way to 
read the data with Phobos instead of the C API.

Adam D. Ruppe <destructionator gmail.com> writes:

On Sunday, 23 July 2017 at 02:07:45 UTC, solidstate1991 wrote:
 Well, it seems the toStringz() function adds a few garbage 
 characters to the end of the filename

How are you using it? The only character it should be adding is 
the zero terminator.

I suspect you might be using it on a static array without slicing 
it down to size first...

Temtaime <temtaime gmail.com> writes:

Hi !
I have a dub package that doing this.

https://github.com/Temtaime/tt-utils/blob/master/source/tt/binary/tests.d

Have a look at the tests.
Currently it has no documentation, but feel free to ask questions