Shell Programming and Scripting

 
$ echo "abc0001d" | awk '{print substr($0,1,5)}'
abc00
$ echo "abc0001d" | awk '{print substr $0,6,3)}'
01d

echo "abc0001d" | sed 's/\(.....\)\(.*\)/\1 \2/'

while read line
do
        firstFour=`echo $line|cut -c1-5`
         lastThree=`echo $line|cut -c6-8`
       echo "First Four= $firstFour"
         echo "Last Three= $lastThree"
done < file

$ x=abc0001d
$ first=${x:0:5}
$ echo $first
abc00
$ second=${x:5:7}
$ echo $second
01d

$ a=abc0001d
$ echo ${a:0:5}
abc00
$ echo ${a:5}
01d