Date: Fri, 21 Aug 2009 17:56:41 -0400
From: "cygwin at sipxx.com" <cygwin@sipxx.com>
Subject: Re: fcntl bug
In-reply-to: <4A8F0944.5020004@byu.net>
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It does reject the argument if the upper bound is reached. On the lower 
end, the linux man page does not specify that negative numbers are not 
allowed as arguments. Note, that fcntl is not supposed to be the same as 
dup2(), i.e., it does NOT duplicate the given fd into the new one 
specified, but should return the next available fd equal to or larger 
than the argument.
Cygwin does this correctly, from what I have tested.


Eric Blake wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> fcntl is supposed to reject attempts to duplicate to an out-of-range fd.
> On Linux, this correctly fails with EINVAL.
>
> #include <fcntl.h>
> #include <string.h>
> #include <errno.h>
> #include <stdio.h>
> int main()
> {
>   int i = fcntl (0, F_DUPFD, -1);
>   printf ("%d %d %s\n", i, errno, strerror (errno));
>   return 0;
> }
>
> - --
> Don't work too hard, make some time for fun as well!
>
> Eric Blake             ebb9@byu.net
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> Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
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