Byron-- You're right... here it is-- strait out of the man page:
If ping does not receive any reply packets at all it will exit with code 1. If a packet
count and deadline are both specified, and fewer than count packets are received by the time
the deadline has arrived, it will also exit with code 1. On other error it exits with code
2. Otherwise it exits with code 0. This makes it possible to use the exit code to see if a
host is alive or not.
thanks for the info-- don't know about the rest of plug-- but the example code is always fun to see.
Justin Gedge
Byron Clark wrote:
On Fri, Apr 15, 2005 at 11:17:12AM -0600, Justin Gedge wrote:
This is where you get back to the whole mess of using grep. You don't want to check wether ping ran or not-- you want to check what the results of ping were. Pipe the results of ping through grep-- and filter on " 0%" or " 100%". Also-- putting the -w for timout is good too-- otherwise ping may sit there for quite a while. I figure-- on a good network [locally] if your ping is over 1s there are other problems at large.
Using grep to see if ping succeeded or not is "the hard way." ping has an exit code of 0 if there are no errors and there is a response; the exit code is 1 or 2 otherwise. I know someone already showed the easy way, but just to reiterate:
if ping -c 1 -w 1 -q example.com &>/dev/null; then echo "example.com is up" else echo "example.com is down" fi
------------------------------------------------------------------------
.===================================. | This has been a P.L.U.G. mailing. | | Don't Fear the Penguin. | | IRC: #utah at irc.freenode.net | `==================================='
.===================================. | This has been a P.L.U.G. mailing. | | Don't Fear the Penguin. | | IRC: #utah at irc.freenode.net | `==================================='
