Shell Programming and Scripting

Last login: Fri Oct 11 23:52:49 on ttys000
AMIGA:barrywalker~> IFS="."
AMIGA:barrywalker~> num="192.168.21.8"
AMIGA:barrywalker~> arr=($num)
AMIGA:barrywalker~> x="${arr[2]}"
AMIGA:barrywalker~> y="${arr[3]}"
AMIGA:barrywalker~> echo "$x"
21
AMIGA:barrywalker~> echo "$y"
8
AMIGA:barrywalker~> _

var="192.168.21.8."
a=$(awk -F. '{print $3}' <<< "$var")
b=$(awk -F. '{print $4}' <<< "$var")
echo $a $b
21 8

$ echo '192.168.21.8.' | sed 's/\([0-9]*\.\)\{0\}\([0-9]*\).*/\2/'
192
$ echo '192.168.21.8.' | sed 's/\([0-9]*\.\)\{1\}\([0-9]*\).*/\2/'
168
$ echo '192.168.21.8.' | sed 's/\([0-9]*\.\)\{2\}\([0-9]*\).*/\2/'
21
$ echo '192.168.21.8.' | sed 's/\([0-9]*\.\)\{3\}\([0-9]*\).*/\2/'
8

var=192.168.21.8
IFS=. read _ _ a b << EOF
$var
EOF

var=192.168.21.8
b=${var##*.}
var=${var%*}
a=${var##*.}

var=192.168.21.8
IFS=. read _ _ a b <<< "$var"

oldIFS=$IFS
....
IFS=$oldIFS

IFS=. read a a a b << EOF