Re: [Qemu-devel] [PATCH 1/6] Fix incorrect check for fdatasync() in configure

["Andreas Färber" <andreas.faerber@web.de>]

Hi Alexandre,

Am 29.05.2011 um 17:46 schrieb Alexandre Raymond:

> According to this excerpt from The Open Group Base Specifications
> Issue 6 (http://pubs.opengroup.org/onlinepubs/009695399/basedefs/unistd.h.html 
> ),
> '>0' indeed means that the functionality is implemented and can be
> used.
> ----8<----
> The following symbolic constants, if defined in <unistd.h>, shall have
> a value of -1, 0, or greater, unless otherwise specified below. If
> these are undefined, the fpathconf(), pathconf(), or sysconf()
> functions can be used to determine whether the option is provided for
> a particular invocation of the application.
>
> If a symbolic constant is defined with the value -1, the option is not
> supported. Headers, data types, and function interfaces required only
> for the option need not be supplied. An application that attempts to
> use anything associated only with the option is considered to be
> requiring an extension.
>
> If a symbolic constant is defined with a value greater than zero, the
> option shall always be supported when the application is executed. All
> headers, data types, and functions shall be present and shall operate
> as specified.
>
> If a symbolic constant is defined with the value zero, all headers,
> data types, and functions shall be present. The application can check
> at runtime to see whether the option is supported by calling
> fpathconf(), pathconf(), or sysconf() with the indicated name
> parameter.
> ----8<----

Indeed, confirmed in Issue 7, thanks a lot. Could you please provide  
me with an updated commit message saying so? Then I'll apply it.

Andreas