Print the two matched variables of awk in same line

This is the script which i wrote.

Date=$(date +'%Y-%m-%d')

for i in `awk -F"[.: ]" '/start/{start=($4 * 3600) + ($5 * 60) + $6;date=$4$5} /end/{print date;print (($4 * 3600) + ($5 * 60) + $6)-start;start=""}' logs.txt`;  do
    echo "$i"
done

The logs.txt consists of :

11.04.2018 09:21:35 aaaaa: start_time
11.04.2018 09:22:35 aaaaa: end_time
11.04.2018 10:45:00 aaaaa: start_time
11.04.2018 11:00:00 aaaaa: end_time

In this the expected output is :

2018-04-11 09:21:35,60
2018-04-11 10:45:00,900

But the output i am getting is :

2018-04-13,0921
2018-04-13,60
2018-04-13,1045
2018-04-13,900

Can anyone rectify what is the error ?

Answer

I thinks this problem should be separated multiple problems. How do you think about below code?

# extract records: log file may contain other informations
awk '$4=="start_time";$4=="end_time"' logs.txt  |
# wrap records:
# # start_time and end_time may appear alternately in the log.
# # wrap a pair into 1 line.
awk '{if(NR%2==1){ printf("%s ",$0) }else{ print }}'    |
# and convert
# # tr command character wise editor, read ``man tr''.
tr '.:' ' ' |
# # make your favorite output
awk -v OFS="," '{
    print $3 "-" $2 "-" $1 " " $4 ":" $5 ":" $6,
    3600 * ($12-$4) + 60 * ($13-$5) + ($14-$6)
    }'

You can see what these code actually do by increment piped commands, as shown below:

$ awk '$4=="start_time";$4=="end_time"' logs.txt
11.04.2018 09:21:35 aaaaa: start_time
11.04.2018 09:22:35 aaaaa: end_time
11.04.2018 10:45:00 aaaaa: start_time
11.04.2018 11:00:00 aaaaa: end_time
$ awk '$4=="start_time";$4=="end_time"' logs.txt    |
> awk '{if(NR%2==1){ printf("%s ",$0) }else{ print }}'
11.04.2018 09:21:35 aaaaa: start_time 11.04.2018 09:22:35 aaaaa: end_time
11.04.2018 10:45:00 aaaaa: start_time 11.04.2018 11:00:00 aaaaa: end_time
$ awk '$4=="start_time";$4=="end_time"' logs.txt    |
> awk '{if(NR%2==1){ printf("%s ",$0) }else{ print }}'  |
> tr '.:' ' '
11 04 2018 09 21 35 aaaaa  start_time 11 04 2018 09 22 35 aaaaa  end_time
11 04 2018 10 45 00 aaaaa  start_time 11 04 2018 11 00 00 aaaaa  end_time
$ awk '$4=="start_time";$4=="end_time"' logs.txt    |
> awk '{if(NR%2==1){ printf("%s ",$0) }else{ print }}'  |
> tr '.:' ' '   |
> awk -v OFS="," '{
>   print $3 "-" $2 "-" $1 " " $4 ":" $5 ":" $6,
>       3600 * ($12-$4) + 60 * ($13-$5) + ($14-$6)
>   }'
2018-04-11 09:21:35,60
2018-04-11 10:45:00,900