Shell Programming and Scripting

NAME=BOB
ADDRESS=COLORADO
PET=CAT
NAME=SUSAN
ADDRESS=TEXAS
PET=BIRD
NAME=TOM
ADDRESS=UTAH
PET=DOG

BOB,COLORADO,CAT
SUSAN,TEXAS,BIRD
TOM,UTAH,DOG

count=1
while read line; do
  output=`echo $line | sed "s/.*=//"`
  echo -n $output
  if [ $count -lt 3 ]; then 
    echo -n ","
    let "count++"
  else
    echo
    count=1
  fi
done < dave.txt

awk -F'=' '{$0=$NF}!(NR%3){ORS=RS}NR%3{ORS=","}1' file

$ sed "s/^[^=]*=//;N;N;s/\n[^=]*=/,/g" file
BOB,COLORADO,CAT
SUSAN,TEXAS,BIRD
TOM,UTAH,DOG

cut -d= -f2 file | paste -d, - - -