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Date: Wed, 21 Jun 2006 11:03:55 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Problem creating device files
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On Jun 21 10:47, Nicolas Boudin wrote:
> 
> Hello,
> 
> I get strange results when trying to create device files with this program:
> 
> #include <sys/stat.h>
> 
> int main (void)
> {
> 	int major, minor;
> 	dev_t dev;
> 
> 	major = 5;
> 	minor = 1;
> 	dev = (major << 8) | minor;
> 
> 	mknod ("test", S_IFCHR | 0666, dev);
> 
> 	return 0;
> }
> 
> After running it, I get:
> 
> # ls -al test
> crw-rw-rw-    1 NBoudin mkgroup-l-d 0, 1281 Jun 21 10:44 test
> 
> However, with "mknod test2 c 5 1":
> crw-rw-rw-    1 NBoudin mkgroup-l-d 5,    1 Jun 21 10:44 test2
> 
> Why do I get this result?

You are making invalid assumptions.  Have a look into
/usr/include/cygwin/types.h and /usr/include/sys/sysmacros.h
and see the light.  After that, make a mental note:

  "Never create a device number other than by using the makedev macro"


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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