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From: Achim Gratz <Stromeko@nexgo.de>
To: cygwin-apps@cygwin.com
Subject: Re: fflush(NULL) clobbers input streams
References: <87k2376jck.fsf@Rainer.invalid>	<20170718095456.GC26902@calimero.vinschen.de>	<20170718105109.GD26902@calimero.vinschen.de>
Date: Tue, 18 Jul 2017 19:21:00 -0000
In-Reply-To: <20170718105109.GD26902@calimero.vinschen.de> (Corinna Vinschen's	message of "Tue, 18 Jul 2017 12:51:09 +0200")
Message-ID: <87fudtlfen.fsf@Rainer.invalid>
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Corinna Vinschen writes:
> Oh, and a plain C testcase, of course...

Call that fflush.c:

--8<---------------cut here---------------start------------->8---
#include <stdio.h>
int
main(int argc, char **argv)
{
    char buf[1024];
    int i;
    char *bp = buf;
    while (1) {
        while ((i = getc(stdin)) != -1
               && (*bp++ = i) != '\n'
               && bp < &buf[1024])
        /* DO NOTHING */ ;
        *bp = '\0';
        fprintf(stdout, "%s", buf);
        fflush(NULL);
        if (i == -1)
            return 0;
        bp = buf;
    }
}
--8<---------------cut here---------------end--------------->8---

Then run:

gcc fflush.c -o fflush
cat fflush.c | ./fflush 2>/dev/null > fflush.out
diff fflush.c fflush.out

If things are working, fflush.c and fflush.out should be identical.
Currently only the first line makes it into fflush.out on Cygwin.


Regards,
Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

Factory and User Sound Singles for Waldorf Blofeld:
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