Alternate command for cut

Hello,

I have a string below

DUMMY=1,2,3,4,5,6

I want to extract fields 1-3 and put it as under in a file
1,2,3

I can do this using cut like below
echo $DUMMY | cut -d, -f1-3

But I would be processing more than 15000 such entries and I found that "cut" was using more CPU. So anyone has any idea an alternate command using awk?

Thanks in Advance
Mohammed

you can you this code

awk -F"," '{print $1","$2","$3}' file_name

as per my concern better to use cut command..

Another ways using KSH :

echo $DUMMY | IFS=, read f1 f2 f3 filler
echo $f1,$f2,$3

or

 IFS=, set -A fields -- $DUMMY
echo ${fields[0]},${fields[1]},${fields[2]}

Jean-Pierre