Date: Sat, 11 Dec 2010 21:23:19 +1100 (EST) From: Bruce Evans <brde@optusnet.com.au> To: Warren Block <wblock@wonkity.com> Cc: freebsd-bugs@FreeBSD.org, freebsd-gnats-submit@FreeBSD.org Subject: Re: bin/153012: iostat(8) requires an argument to -c option Message-ID: <20101211210136.M2559@besplex.bde.org> In-Reply-To: <201012102359.oBANxHIs027355@red.freebsd.org> References: <201012102359.oBANxHIs027355@red.freebsd.org>
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On Fri, 10 Dec 2010, Warren Block wrote:
>> Description:
> iostat(8) says:
>
> -c Repeat the display count times. If no repeat count is specified,
> the default is infinity.
This used to be correct. It said "if no wait interval is specified, then
the default [for the wait interval] is 1 second". This was a bit confusing
since it didn't say that the default is for the wait interval. Now it is
just broken, since it is the -c option and not its repeat count that is
optional.
> But if you try to run it without a repeat count:
>
> % iostat -c
> iostat: option requires an argument -- c
> usage: iostat [-CdhIKoTxz?] [-c count] [-M core] [-n devs] [-N system]
> [-t type,if,pass] [-w wait] [drives]
The synopsis and usage message correctly specify that -c must have an arg.
The -w option has the complement of this breakage.
Either -w wait or the the normal way using the undocumented alias for this
("iostat wait", where `wait is a number') must be used to specifiy the wait
time for -c. Not documenting this may be intentional, but it became
especially broken when the `drives' option was added, since according to
the synopsis and usage message "iostat 1" says to give statistics for the
drive named "1", but it is actually an alias for "iostat -w 1".
Bruce
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