Date: Tue, 10 Jul 2012 18:02:50 +0300 From: Volodymyr Kostyrko <c.kworr@gmail.com> To: Konstantin Belousov <kostikbel@gmail.com> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org>, freebsd-standards@freebsd.org Subject: Re: kern/149857: [kqueue] kqueue not reporting EOF under certain circumstances Message-ID: <4FFC441A.2010500@gmail.com> In-Reply-To: <20120710142746.GD2338@deviant.kiev.zoral.com.ua> References: <4FFC1D2D.4020405@gmail.com> <20120710140203.GA2338@deviant.kiev.zoral.com.ua> <4FFC39D9.6080809@gmail.com> <20120710142746.GD2338@deviant.kiev.zoral.com.ua>
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Konstantin Belousov wrote:
>> So you mean this is just my false assumption that EOF _should_ occur on
>> stdin? And it actually occurs only if source is a process which can send
>> EOF?
>
> 'Source' cannot be a process. Read filter on pipes can return EV_EOF.
> Read filter on vnodes (read: regular files) does not return EV_EOF,
> except in situation that is created by manual intervention of
> administrator.
This keeps me puzzled. How then I can tell that file at stdin is already
at EOF? You mean I should treat stdin like normal vnode-backed file?
off_t pos = 0, endpos;
lseek(fileno(stdin), 0, SEEK_END);
endpos = ftell(stdin);
lseek(fileno(stdin), 0, SEEK_SET);
... and then later check it with:
if(endpos != -1) {
pos += kev.data;
if(pos >= endpos) {
printf("end reached\n");
return(0);
}
}
Is this a correct way to detect EOF? I'm letting besides that I should
also detect vnode changes and update max file size accordingly.
> It should have been clear from my previous response.
Please excuse me, I'm a bit new to this things...
--
Sphinx of black quartz judge my vow.
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