Re: sharing STDOUT in multiple sha256sum processes

[Pádraig Brady]

On 05/16/2014 07:15 PM, Assaf Gordon wrote:
> Hello,
> 
> I'd like to ask your advice, to verify that my command is correct.
> 
> I'm trying to calculate sha256 checksum on many files, in parallel.
> 
> A contrived example would be:
> $ find /path/ -type f -print0 | xargs -0 -P5 -n1 stdbuf -oL sha256sum > 1.txt
> 
> Which would run at most 5 processes of "sha256sum",
> and the output of all would be the file 1.txt.
> 
> Is it correct to assume that because "sha256sum" prints one line per file, 
> and "stdbuf -oL" makes it line-buffered,
> that the content in "1.txt" will be valid (i.e. no inter-mixed lines from 
> different processes) ?

That's correct.

Note you don't even need the stdbuf since coreutils 8.1:
http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=710fe413

thanks,
Pádraig.