setmode again

Steven Schveighoffer schveiguy at
Sat Aug 9 09:32:13 PDT 2008

"Brian Myers"
> Ok, here's the current version I tried:
> import std.string;
> import std.stdio;
> import;
> extern (Windows)
> alias int function(int,int) setmode_f;
> //extern ( C ) int setmode(int,int);
> void main(char[][] args)
> {
>    int O_BINARY = 0x8000;
>    setmode_f f;
>    HMODULE m = cast(HMODULE) LoadLibraryA(toStringz("msvcrt.dll"));
>    f = cast(setmode_f) GetProcAddress(m, toStringz("_setmode"));
>    if (f(fileno(stdout), O_BINARY) < 0)
>        writefln("setmode failed.");
> //    if (setmode(fileno(stdout) ,O_BINARY) < 0)
> //        writefln("setmode failed.");
>    writef("test line1\r\ntestline2\n");
> }
> No dice. Still doing CR/LF translation.
> Steven Schveighoffer Wrote:
>> "Brian Myers" wrote
>> > No, I haven't because I thought that would result in a compiler or 
>> > linker
>> > error. What happens is the function is executed at run time, but has no
>> > effect. I think I have a better idea now thought:
>> Try the extern(Windows).  The difference is the call stack layout.  what
>> could be happening is you are calling a function one way, but the 
>> function
>> expects to be called a different way.  So it isn't reading the parameters
>> like you think it is (in fact, it might be reading garbage).
>> You won't get a compiler or linker error because you are not linking the
>> function in, you are dynamically loading it.
>> -Steve

I think I see the problem.  dmd is using the digital mars C functions, not 
the MS C functions.  I think the binary/text translation is done in the C 
library not in the OS, so setmode will only affect MS C functions. 
Unfortunately, in looking at Digital Mars' documentation, you cannot reopen 
an open FILE * object by descriptor only.  I tried using _fdopen, but that 
isn't available in the lib that ships with dmd.

More proof that it's in the C lib, if you use Tango (which only uses system 
calls for I/O), setmode also does nothing, but Cout also prints only LF.


More information about the Digitalmars-d mailing list