Re: "ls -l": Avoid unnecessary getxattr() overhead

[Eric Blake]

On 02/17/2012 03:35 AM, Jim Meyering wrote:

> Instead, I've realized that I can eliminate the need for the wc post-
> processing by using the fact that our contrived output file is seekable:
> rather than simply writing to fd, first seek to position 0 each time,
> and write the count:

> 
>   # Finally, to test it, do this:
>   eval "LD_PRELOAD=$PWD/k.so ls --color=always -l . $fd>x" || exit 1
> 
> Hmm... that means the case of no getxattr calls would still
> require a little special handling to map "empty file" to "0".

No.  Just add 'echo 0 >x' prior to the actual test, so that x is never
empty.

-- 
Eric Blake   address@hidden    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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