Re: [Help-tar] problem when redirecting tar output.

[shreyas waghmare]

Thanks for your reply,

Its clear for me now.

I actually want to monitor time required for tar to read all files in given hierarchy and do not want it to create archive, so i redirected output to /dev/zero, 
Because when i redirect output to /dev/zero it opens and reads the file but do not create any archive.

Is this the correct way to do? Will i get correct time reading which i intend to take?


Thanks,
Shreyas

On Fri, Feb 20, 2009 at 4:50 PM, Sergey Poznyakoff <address@hidden> wrote:

shreyas waghmare <address@hidden> ha escrit:

>    If my information and understanding above is right, then why am i
>    getting these different time when i perform tar on same hierarchy?

GNU tar explicitly checks if the archive is beign written to /dev/null,
and if so, it does not do any real archiving. That is, it does not
actually open and read any files. This behavior is documented in

 http://www.gnu.org/software/tar/manual/html_section/file.html#SEC99

>    I want to measure performance in terms of time required to perform tar
>    on a given hiearchy. so I am not sure which command is correct.

In that case, create a real archive on the file system and delete it
after measuring is done.

Regards,
Sergey

-- 
Shreyas Waghmare