Re: [gentoo-user] irritating cron habit : solved
> > btw, if I need to check if the network is up in a script, I usually do > > ping -q -c1 -w4 some.remote.host >/dev/null 2>&1 && > command-to-run-if-remote-host-reachable > > It the advantage that it checks directly connection to the host > you wish to connect to, so it also won't run the command if your network > is up, but the remote host is inaccessible... > > If your server doesn't respond to pings, just use some other server > (eg google's public dns 8.8.8.8) > Or you could use hping, which has the advantage that it tests the actual service you want to use, rather than just the host it sits on; sphinx adam # hping2 -c 1 -S -p 80 www.google.com >/dev/null 2>&1 && echo "it worked" it worked
Re: [gentoo-user] irritating cron habit : solved
On Mon, Feb 21, 2011 at 12:39:43AM -0500, Philip Webb wrote: > 110220 Philip Webb wrote: > > 110220 Florian Philipp wrote: > >> Just change your cron job to look like > >> 'test -e /var/run/dhcpcd.pid && fetchmail' > > That's by far the simplest & it still fetches the mail, > > so we'll see if it also avoids the occasional internal spam msgs. > > Indeed it does: I tried delaying starting the I/net connection > & there is no 'dead.letter' file. Thanks again. > > PS the file is /var/run/dhcpcd-eth0.pid , not as above. btw, if I need to check if the network is up in a script, I usually do ping -q -c1 -w4 some.remote.host >/dev/null 2>&1 && command-to-run-if-remote-host-reachable It the advantage that it checks directly connection to the host you wish to connect to, so it also won't run the command if your network is up, but the remote host is inaccessible... If your server doesn't respond to pings, just use some other server (eg google's public dns 8.8.8.8) The -w4 paramater controls how long to wait for reply if the network is up, but the reply is not comming (ie a network problem, if your network connect is down, ping will return immediately with a "network unreachable" or "unknown host" error) yoyo
Re: [gentoo-user] irritating cron habit : solved
110220 Philip Webb wrote: > 110220 Florian Philipp wrote: >> Just change your cron job to look like >> 'test -e /var/run/dhcpcd.pid && fetchmail' > That's by far the simplest & it still fetches the mail, > so we'll see if it also avoids the occasional internal spam msgs. Indeed it does: I tried delaying starting the I/net connection & there is no 'dead.letter' file. Thanks again. PS the file is /var/run/dhcpcd-eth0.pid , not as above. -- ,, SUPPORT ___//___, Philip Webb ELECTRIC /] [] [] [] [] []| Cities Centre, University of Toronto TRANSIT`-O--O---' purslowatchassdotutorontodotca
