getting network configuration

antken · 10-18-2002, 07:10 AM

hi,

i have a script on my linux box that i have written
to run it you basically type ethinfo eth0

and it returns basic information about the adapters configuration ( ip, subnet, and adapter type ie ethernet or local )
this script is for the benifit of my boss who can't seem to get to grips with ifconfigs out put

how would i go about getting my script to check if the interface exists first then printing its output? ( code below)

thanks
antken

here is the script:

Code:

#!/bin/sh


e_ip=`/sbin/ifconfig $1 | grep inet | cut -f 2 -d : | cut -d ' ' -f 1`
e_snet=`/sbin/ifconfig $1 | grep Mas | cut -d : -f 4`
e_typ=`/sbin/ifconfig $1 | grep encap | cut -f 2 -d : | cut -d ' ' -f 1`

echo
echo IP Configuration for interface $1 is:
echo
echo This interface is: $e_typ
echo IP address: $e_ip
echo Subnet: $e_snet
echo

exit 0

unSpawn · 10-18-2002, 12:55 PM

For instance looking for every interface in class eth:

#!/bin/sh
for interface in $(cat /proc/net/dev | grep "eth" | cut -d ":" -f 1 | tr -d " "); do
# replace your scripts "$1" with "$interface":
e_ip=`/sbin/ifconfig $interface | grep inet | cut -f 2 -d : | cut -d ' ' -f 1`; (etc etc...)
done
exit 0

Or you could do
case "$1" in
eth|tap)
for interface in $(cat /proc/net/dev | grep "$1" | cut -d ":" -f 1 | tr -d " "); do
# replace your scripts "$1" with "$interface":
e_ip=`/sbin/ifconfig $interface | grep inet | cut -f 2 -d : | cut -d ' ' -f 1`; (etc etc...)
done
;;
*)
echo "$(basename $0): first arg needs to be one of [eth|tap]"
exit 1
esac

...or you scrape the interface names from /etc/sysconfig/network-scripts/ifcfg* if you don't like /proc

leed_25 · 10-20-2002, 03:09 PM

Quote:

if i understand your question correctly, maybe something like this would do:

Code:

if [ ! -z $e_typ ]; then
    echo This interface is: $e_typ
    echo IP address: $e_ip
    echo Subnet: $e_snet
fi

you might want to do 'man test' for lots of info on the [ ... ] shell command.