On Fri, 8 Mar 2019 22:56:36 +0100, Alessandro wrote in message <[email protected]>:
> On 08/03/19 at 18:38, Arnt Karlsen wrote: > > > > ..my /etc/cron.d/machine-id: > > PATH=/bin:/usr/bin:/sbin:/usr/sbin > > > > # ..a new /etc/machine-id every minute... ;o) > > * * * * * root date |md5sum |cut -d" " -f-1 >/etc/machine-id |tee > > >/dev/null 2>&1 > > > What is tee doing there? ..allows logging the generated IDs with e.g. " |tee >>/var/log/machine-IDs ", some people might need to do that. > It duplicates it's standard input to each of the files it sees as > parameters, and it has none. > > Plus, it emits it's standard input to it's standard output, which > gets discarded. > > What is the purpose of doing this? > > > I'd just do this instead: > > echo $RANDOM | md5sum | cut -c 1-32 > /etc/machine-id > > > or maybe: > > > dd count=1 if=/dev/urandom 2> /dev/null | md5sum | cut -c 1-32 > > /etc/machine-id ..both valid improvements, me, I might go: " * * * * * root \ fortune &&date |md5sum |cut -d" " -f-1 >/etc/machine-id |tee \ >/dev/null 2>&1 " to keep this lightweight in my end and not in the other end. :o) -- ..med vennlig hilsen = with Kind Regards from Arnt Karlsen ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
