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Message-ID: <015501c4290b$96c839e0$0200a8c0@em.noip.com>
From: "Enzo Michelangeli" <em AT em DOT no-ip DOT com>
To: <cygwin AT cygwin DOT com>
Subject: Re: 1.5.9-1: weird console I/O behaviour compiling with -mno-cygwin
Date: Fri, 23 Apr 2004 16:18:11 +0800
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Quick update: The same testcase, compiled under MSYS 1.0.10 with  Mingw
gcc (gcc 3.2.3 (mingw special 20030504-1)), does not exhibit the problem
No.1, but still shows the No.2 when run in a standard DOS box. When run
inside a MSYS window it does not recognize as EOF either Ctrl-Z or Ctrl-D,
so the test No.2 can't take place...

Enzo

----- Original Message ----- 
From: "Enzo Michelangeli" <em AT em DOT no-ip DOT com>
To: <cygwin AT cygwin DOT com>
Sent: Friday, April 23, 2004 10:32 AM
Subject: Re: 1.5.9-1: weird console I/O behaviour compiling
with -mno-cygwin

Hello,

Please consider the following testcase:

------ begin weirdio.c -------
#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
 int rc;
 char buf[1024];
 char *s = "read() done\n";

 for(rc=1;rc>0;) {
  rc = read(0, buf, sizeof(buf) - 1);
// sleep(0); temporarily uncommented
  write(1, s, (size_t)strlen(s));
 }
}
------- end weirdio.c -------

when compiled with "gcc -o weirdio weirdio.c" it behaves as expected:

-----------------------------
em AT emnb ~/weirdio
$ ./weirdio
$ ./weirdio
aaa           <--- "Return" key hit on the keyboard
read() done
aaa           <--- "Return" key hit on the keyboard
read() done
bbb           <--- "Return" key hit on the keyboard
read() done   <--- EOF (Ctrl-D) hit on the keyboard
read() done   <--- last write() duly executed

em AT emnb ~/weirdio
$
-----------------------------

However, compiling with "gcc -mno-cygwin -o weirdio weirdio.c" two strange
things happen:

1. Only when executed inside a cygwin window (at the bash prompt), the
first time "read()" returns as if someone had hit the "Return" key
(further investigation with gdb revealed that read() returned 1 and placed
one \n character in the buffer).

2. Either at the bash prompt, or in a plain DOS window (under Win98SE) the
last "read() done" after EOF (which now is Ctrl-Z) is NOT printed. BUT, it
is duly printed if the "sleep(0)" (or sleep with any other argument) is
uncommented!

Unfortunately, I have no MSVC++ compiler, so I can't see what happens
compiling with the tools of the Evil Empire.

Any idea?

Enzo



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