2011/10/20 Ole Tange <[email protected]>: > On Thu, Oct 20, 2011 at 1:01 PM, Hans Schou <[email protected]> wrote: >> 2011/10/20 Ole Tange <[email protected]>: >>> On Wed, Oct 19, 2011 at 11:43 PM, Hans Schou <[email protected]> wrote: >>>> On Sat, 15 Oct 2011, Ole Tange wrote: >>>> >>>>> It is probably time to get a new video out. >>>>> >>>>> What would you like to see demoed in that? > : >> Scan your private net for which IP-numbers is in use. Save data in a >> file for later handling: >> >> time parallel --tag -j+128 ping -W2 -c1 192.168.112.{} \| grep from >> ::: $(seq 254) | tee foo > > Good examples, though I would probably do: > > seq 254 | parallel --tag -j0 ping -W2 -c1 192.168.4.{} |grep > from|cut -f1|sort -nu > > Or use nmap, which has a much shorter syntax: > > nmap -T insane -sP 10.10.13.0/24
Yes, but slow: $ time nmap -T insane -sP 192.168.112.0/24 .... cut .... real 0m17.153s user 0m0.020s sys 0m0.004s With parallel and -j0 I am down to: real 0m3.207s user 0m0.840s sys 0m1.480s System usage is higher but Im alone on this box. >> I use -j+128 here to start more ping's at the same time. > > You need to learn -j0. Nice. That cut off 1.5sec (I will save them for later in my life). /hans
