# list all interfaces that are "up"
ifconfig -l -u

# Let's say I get this as a result:
lo0 en0 en1

#I need to then do this (for any item listed from the previous command):
ipconfig getifaddr lo0
ipconfig getifaddr en0
ipconfig getifaddr en1

# And I need each interface listed separately when all is said and done. Like this:
lo0 127.0.0.1
en0 10.0.0.1
en1 23.45.67.89

#!/bin/ksh

ifconfig -l -u | while read if
do
    echo "${if} $(ipconfig getifaddr ${if})"
done

#!/bin/ksh

for if in $(ifconfig -l -u)
do
    echo "${if} $(ipconfig getifaddr ${if})"
done

#!/bin/ksh

for if in $(ifconfig -l -u | grep 'lo0')
do
    echo "${if} $(ipconfig getifaddr ${if})"
done

interfaces=`(for if in $(ifconfig -l -u)
do
    echo "${if} $(ipconfig getifaddr ${if})"
done)`

# here's the result from your code:
get if addr lo0 failed, (os/kern) failure
lo0 
en0 205.139.21.89
en1 10.0.1.25

# Now I need to be able assign each line to a variable, so ultimately I get something like this:
Ethernet: 205.139.21.89
Airport: 10.0.1.25