• novice2 (20/20) Mar 01 2015 Could you, please, help me to understand, why code:
• ketmar (6/7) Mar 01 2015 'cause winapi functions never sets `errno`. `errno` is a libc feature,=2...
• Vladimir Panteleev (16/18) Mar 01 2015 Here's the right way to do this:
• novice2 (3/3) Mar 01 2015 Thans guys!
• novice2 (2/2) Mar 01 2015 Ha, i found

"novice2" <sorry noem.ail> writes:

Could you, please, help me to understand, why code:

////////////////
import std.c.windows.windows;
import std.exception: ErrnoException;
import std.stdio: writefln;
import std.string: toStringz;

void main ()
{
   CreateFileA(toStringz("nonexisting file name"), GENERIC_READ, 
FILE_SHARE_READ, null, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 
null);
   auto ex = new ErrnoException("CreateFileA");
   writefln("ex.errno=%d, ex.msg=%s, lasterror=%d", ex.errno, 
ex.msg, GetLastError());
}
////////////////

prints:
ex.errno=0, ex.msg=CreateFileA (No error), lasterror=2

I wanted it will be:
ex.errno=2, ex.msg=CreateFileA (File not found), lasterror=2

ketmar <ketmar ketmar.no-ip.org> writes:

On Sun, 01 Mar 2015 16:39:27 +0000, novice2 wrote:

 Could you, please, help me to understand, why code:

'cause winapi functions never sets `errno`. `errno` is a libc feature,=20
and winapi knows nothing about libc. besides, `GetLastError()` is not=20
required to return correct errno codes.

so you have to either use libc funcions, or translate `GetLastError()`=20
codes to errno manually.=

"Vladimir Panteleev" <vladimir thecybershadow.net> writes:

On Sunday, 1 March 2015 at 16:39:29 UTC, novice2 wrote:
 I wanted it will be:
 ex.errno=2, ex.msg=CreateFileA (File not found), lasterror=2

Here's the right way to do this:

////////////////////////// test.d //////////////////////////
import std.c.windows.windows;
import std.string : toStringz;
import std.windows.syserror : wenforce;

void main ()
{
     auto handle = CreateFileA(toStringz("nonexisting"),
         GENERIC_READ, FILE_SHARE_READ, null, OPEN_EXISTING,
         FILE_ATTRIBUTE_NORMAL,
         null);
     wenforce(handle != INVALID_HANDLE_VALUE, "CreateFileA");
}
////////////////////////////////////////////////////////////

See std.windows.syserror for more information.

"novice2" <sorry noem.ail> writes:

Thans guys!

wenforce not sutable - error code is lost.
may be, i will use modified wenforce, wich throws ErrnoException.

"novice2" <sorry noem.ail> writes:

Ha, i found
std.windows.syserror: WindowsException, wenforce;