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Date: Thu, 11 Nov 2010 12:06:31 GMT
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From: Martin Simmons <martin@lispworks.com>
To: mark@exonetric.com
In-reply-to: <871369D9-7D63-4CE0-BB87-B8C46A62B271@exonetric.com> (message
	from Mark Blackman on Wed, 10 Nov 2010 22:28:27 +0000)
References: <871369D9-7D63-4CE0-BB87-B8C46A62B271@exonetric.com>
Cc: freebsd-fs@freebsd.org
Subject: Re: ZFS and pathconf(_PC_NO_TRUNC)
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>>>>> On Wed, 10 Nov 2010 22:28:27 +0000, Mark Blackman said:
> 
> I note that when testing the pathconf(2) NO_TRUNC property 
> on a ZFS filesystem, I get a ENOENT, "No such file or directory".
> 
> I'm not sure if this qualifies as correct behaviour, but thought
> a learned soul on this list could enlighten me.
> 
> I've attached the C snippet I used for testing.
> 
> #include <unistd.h>
> #include <stdlib.h>
> #include <stdio.h>
> #include <string.h>
> #include <errno.h>
> 
> int main(int argc, char *argv[]){
>   int result;
> 
>   result=pathconf(argv[1], _PC_NO_TRUNC);
>   printf("for %s: no_trunc is %d\n",argv[1],result);
>   if (result<0)
>     perror(NULL);
>   1;
> }

Your call to printf is clobbering the real errno, which is EINVAL.  That is an
allowed value according to the pathconf man page:

     [EINVAL]           The implementation does not support an association of
                        the variable name with the associated file.

So it is correct, but maybe not useful.

__Martin