I just tried following
ls *.dat|sort -t"_" -k2n,2|while read f1 && read f2; do
awk '{print}' $f1
awk FNR==1'{print $1,$2,$3,$4,$5,"*","*","*" }' OFS="\t" $f2
awk '{print}' $f2
done
got following result
18-Dec-1983 11:45:00 AM 18.692 84.672 0 25.4 24
18-Dec-1983 11:45:00 AM 18.692 84.672 5 25.5 24
18-Dec-1983 11:45:00 AM 18.692 84.672 10 26 24
18-Dec-1983 03:22:00 PM 18.327 84.29 * * *
18-Dec-1983 03:22:00 PM 18.327 84.29 0 24.5 24
18-Dec-1983 03:22:00 PM 18.327 84.29 5 24.6 24
18-Dec-1983 03:22:00 PM 18.327 84.29 10 24.8 24
18-Dec-1983 03:22:00 PM 18.327 84.29 40 27.1 24
18-Dec-1983 03:22:00 PM 18.327 84.29 45 27 24
18-Dec-1983 06:45:00 PM 18.025 83.962 0 26.4 23 -- > before this line * symbol suppose to come
18-Dec-1983 06:45:00 PM 18.025 83.962 5 26.5 23
18-Dec-1983 06:45:00 PM 18.025 83.962 10 26.5 23
18-Dec-1983 06:45:00 PM 18.025 83.962 15 26.8 23
Can anyone tell me why it's not coming and what's solution ?