UNIX for Beginners Questions & Answers

ant1 1,2,3,4 bat1
ant1 5,6,7,8 bat2

ant1 1 bat1
ant1 2 bat1
ant1 3 bat1
ant1 4 bat1
ant1 5 bat2
ant1 6 bat2
ant1 7 bat2
ant1 8 bat2

$ cat mytst
ant1 1,2,3,4 bat1
ant1 5,6,7,8 bat2
$ awk '{c=FS$NF RS$1FS;gsub(/,/,c,$0)}1' mytst
ant1 1 bat1
ant1 2 bat1
ant1 3 bat1
ant1 4 bat1
ant1 5 bat2
ant1 6 bat2
ant1 7 bat2
ant1 8 bat2

#!/bin/bash

while read a b c 
do
IFS=$','
for i in $b
do
echo $a $i $c
done
IFS=$' '
done < file

while read a b c
do
  printf "$a %s $b\n" ${b//,/ }
done < file

printf "$a %s $c\n" ${b//,/ }

${string//substring/replacement}
Replace all matches of substring with replacement.