check-network -- Determine if the network is up; dunno if we can go anywhere

gistfile1

#!/bin/sh

# Check the status of the network connection.
# Thanks to grnmtn on Freenode for this script!
#
# *0* return value indicates the network connection is active. No guarantees on
# the quality of the connection, or if the Internet works. We just have a cable
# in our ass, and it's on.
#
# non-zero return values indicate there was an error somewhere in this script.
# Any errors should be considered a notification that the network is down, or
# otherwise inaccessible. Therefore, don't download anything, since you'll just
# get a bunch of errors.
#
# ------------
#
# How we do this:
#  1) Find the IP of the gateway (arp)
#  2) Isolate the gateway's IP (awk)
#  3) Remove the extra human text that machines don't need (grep -v)
#  4) Send a single packet to that IP. (ping)
#  5) Since ping doesn't have a true quiet option, move the output to /dev/null


ping -c 1 `arp|awk {'print $1'}|grep -v Add` &>/dev/null