CODEWITHSUNDEEP
cconsolecygwinhttp-redirectstdout
blabla999
blabla999

Reputation: 3200

How to AllocConsole + Stdout redirect under cygwin

I have a complex >>cygwin<< windows application (aka. subsystem windows), and I want to add a debug console. I already tried the following variants, but none works for me.

The console appears with changed title, but remains dead-black, no output shown.

Variant 1)

ok = AllocConsole();
if (ok) {
    h = GetStdHandle(STD_OUTPUT_HANDLE);
    fd = _open_osfhandle((intptr_t)h, O_TEXT);
    fp = _fdopen( fd, "w" );
    *stdout = *fp;
    setvbuf( stdout, NULL, _IONBF, 0 );
    fprintf(stdout, "Hello worldd\n");
    SetConsoleTitle("VM Debug");
}

Variant 2)

freopen("conout$","w",stdout);
fprintf(...

Variant 3)

freopen("/dev/conout","w",stdout);
fprintf(...

This may have been answered already many times, but none of the solutions worked for me.

Can anyone please help me?

But please keep in mind: it MUST be a cygwin problem and I need a cywin solution, as I know that one or the other variant works under MSVC or BorlandC. Any answer helps, even one saying that cygwin is broken and there is no solution for me.

Upvotes: 2

Views: 1297

Answers (1)

Giuseppe Guerrini
Giuseppe Guerrini

Reputation: 4428

Yes, it is a cygwin problem. Cygwin's guys actually have worked hard to simulate as much as possible an "unix" environment, so the common W32 tricks can't work. You can anyway write your messages on the new console by using the WriteConsole function, but I see it isn't what you want. In the past I had a similar problem, ad solved it by creating a pipe(), redirecting it to stdout/stderr, and creating a thread that received characters from the pipe end wrote them to the new console via WriteConsole. Not easy.

Also, I think that the cygwin's console management has changed many times with the different versions, so maybe that a trick that seems to work with one version stops working wit another one.

It's a wild world...

Upvotes: 1

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