On 10/10/2013 05:49 AM, Kyle Sallee wrote: > Please forgive the inconvenience. > Attaching a gzipped patch file > ensures the integrity of patch file content. > I should have presented only the idea > rather than a patch for the implementation. > > I concur dd is already suited to the task. > > Please consider > > | sed 's/^/if=/' | xargs -r --max-lines=1 dd iflag=direct # in contrast > with > | xargs -r --max-lines=4096 cat -d -- > > Invoking dd 466059 times costs only a slight performance decrease > as compared with invoking cat 114 times. > However, this example probably represents rare usage for cat. > > Thanks for granting the time and consideration.
Fair point, but still not worth adding to cat(1) since it's not special in this regard. Something like this might be more appropriate: https://github.com/Feh/nocache Note that doesn't avoid the page cache completely, and so may be more performant/portable than O_DIRECT. (dd has this functionality too as described at 'nocache' at: http://www.gnu.org/software/coreutils/manual/html_node/dd-invocation.html) cheers, Pádraig.
