[DJ Mogarych]

Сами-то пытались?

[greg zakharov]

Решение "в лоб".

Код:

#!/usr/bin/env bash
x=`awk -F'[. ]' '$9 == "E" {
  cmd = "date -d \"" $6 " " $7 "\" +%s"
  cmd | getline ts
  close(cmd)

  printf ":%d", ts
  next
} NR > 1 {print ""}{p=$9}' msg.txt | awk '{
  system("echo \"("$NF"-"$2") / 60\" | bc 2>/dev/null")
}' FS=\:`
echo "Number of events: `sed -n '$=' <<< $x`   Events durations:" $x