UNIX for Beginners Questions & Answers

$ help printf
printf: printf [-v var] format [arguments]
    Formats and prints ARGUMENTS under control of the FORMAT.
    
    Options:
      -v var	assign the output to shell variable VAR rather than
    		display it on the standard output
    
    FORMAT is a character string which contains three types of objects: plain
    characters, which are simply copied to standard output; character escape
    sequences, which are converted and copied to the standard output; and
    format specifications, each of which causes printing of the next successive
    argument.
    
    In addition to the standard format specifications described in printf(1),
    printf interprets:
    
      %b	expand backslash escape sequences in the corresponding argument
      %q	quote the argument in a way that can be reused as shell input
      %(fmt)T output the date-time string resulting from using FMT as a format
            string for strftime(3)
    
    The format is re-used as necessary to consume all of the arguments.  If
    there are fewer arguments than the format requires,  extra format
    specifications behave as if a zero value or null string, as appropriate,
    had been supplied.
    
    Exit Status:
    Returns success unless an invalid option is given or a write or assignment
    error occurs.

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

$ cat ooo
ant1 1,2,3,4 bat1
ant1 5,6,7,8 bat2
a%c%s 6,%c,9,0 a%d%%o2

$ while read a b c; do   printf "${a//%/%%} %s ${c//%/%%}\n" ${b//,/ }; done <ooo
ant1 1 bat1
ant1 2 bat1
ant1 3 bat1
ant1 4 bat1
ant1 5 bat2
ant1 6 bat2
ant1 7 bat2
ant1 8 bat2
a%c%s 6 a%d%%o2
a%c%s %c a%d%%o2
a%c%s 9 a%d%%o2
a%c%s 0 a%d%%o2