ifconfig gives me a lot of information but not exactly how I want it.

My linux PC is a dhcp client.
Assuming that my ip address is 192.168.5.10 and the gateway is 192.168.5.1

Can you help me with a script that determines my ip address and gateway and returns it in the format

ip_192.168.5.10_gateway_192.168.5.1

I need to pass this as a value to another script.

Thanks.

You can get the ip address of the interface using ifconfig or ip. The route you will need to use another source, either the "route" command or from the /etc/sysconfig/network/routes (might be in /etc/routes instead).
For example to extract the second column of the routes file to obtain the default gateway:
awk '/default/{print $2}' /etc/sysconfig/network/routes
or using the "route" command:
/sbin/route | awk '/default/{print $2}'

To extract the ipaddress from "/sbin/wlan0" for example:
/sbin/ifconfig wlan0 | sed -n '2s/.*inet addr:\([^ ]*\).*/\1/p'
In a script you may have something like this:
interface=$1
/sbin/ifconfig $interface | sed -n '2s/.*inet addr:\([^ ]*\)/\1/p'
The outputs can be assigned to variables and reassembled like this
ipgat="ip_$address_gateway_$gateway"

Just a little something to get you started:

You can get gateway by netstat -nr, do a little parsing, then just concatenate your variables to get your required format. Let me know if you need more help.

Sorry jschiwal, I had not refreshed my page to see that you had posted already and to note an excellent solution. Again, my apologies.