[Info-vax] OS implementation languages

[Johnny Billquist]

On 2023-08-31 14:15, Simon Clubley wrote:
> On 2023-08-30, Bob Gezelter <gezelter at rlgsc.com> wrote:
>>
>> The other day I needed to copy a bare partition on a linux system. When refreshing my recollection of dd, noted that dd, for historical reasons, copies one block at a time. Increased performance by reading/writing a megabyte at a time.
>>
> 
> :-)
> 
> Adjusting dd command line options for efficiency is one of the first things
> you learn to do when you start using dd for "serious" things. :-)

Yes. That can make a *huge* difference.

> I learnt that back in the late 1990s when it comes to dd...
> 
> BTW, did you know you can send dd a signal to tell you how far along
> in the copy process it is and to tell you how fast the copy is going ?

Yes. But which signal differs between systems. In Linux you use SIGUSR1 
(for lack of any better choice).
In BSD you send it SIGINFO, which you can configure your terminal to 
send when you hit something like ^T (now, where have I seen ^T for 
printing out some information before...? ;-) ).

   Johnny