Modify the output of the command "last" - linux

Question

I want to make a program in bash to display the output of last with this format:
username | number of sessions | duration of sessions | maximum session length
I already did the first two columns but don´t know how to do the rest.
This is the code I wrote for the username and number of sessions:
last |& tee last.txt
cut -d' ' -f1,2 last.txt > last1.txt
thanks

Answer 1

You can try with something like this. Its not perfect but very close :
#!/bin/bash
unique_users="$( last | awk ' {print $1} ' | sort | uniq | grep -v 'shutdown\|wtmp\|reboot' | awk 'NF' )"
for user in $unique_users
do
number_of_sessions="$( last $user | awk '{print $NF}' | grep '^(' | tr -d '()' | wc -l )"
total_mins="$( last $user | awk '{print $NF}' | grep '^(' | tr -d '()' | awk '{ split($1, t, ":"); print (t[1]*60+t[2]) }' | awk '{ sum+=$1}END{print sum/60}' )"
max_length="$( last $user | awk '{print $NF}' | grep '^(' | tr -d '()' | awk '{ split($1, t, ":"); print (t[1]*60+t[2]) }' | sort -rn | head -1 | awk '{ sum+=$1}END{print sum/60}')"
printf "$user | $number_of_sessions | $total_mins | $max_length\n"
done
Regards!

Answer 2

I'm assuming last output same as Mint19
owner tty7 :0 Sun Nov 17 06:18 gone - no logout
owner tty7 :0 Sun Nov 10 11:13 - crash (6+18:34)
owner tty7 :0 Thu Nov 7 14:10 - 11:11 (2+21:00)
owner pts/1 :0 Wed Nov 6 21:48 - 21:48 (00:00)
owner pts/1 :0 Wed Nov 6 21:37 - 21:40 (00:03)
The file is sorted by timestamp, and the 10th column contain the session duration: either (HH:MM), or (DAYS+HH:MM). Small awk will do the trick. Script only count terminated session - ignoring crashed/still running sessions.
Total is session time in minutes.
#! /usr/bin/awk -f
{
id=$1
if ( match($10, /\(([0-9]+)\+\)?([0-9][0-9]):([0-9][0-9])/, a) ) {
dur_min = a[1]*24*60 + a[3] * 60 + a[4] ;
s_count[id]++ ;
s_total[id] += dur_min
if ( dur_min > s_max[id] ) s_max[id] = dur_min
}
}
END {
print "ID", "Count", "Total(min)", "Max(min)"
for (id in s_count) {
print id, s_count[id], s_total[id], s_max[id]
} ;
}