Calc and plot durations from log file

calc_and_plot_durations_from_log_file.sh

#!/bin/bash

# Given a logfile with pairwise loglines when an event starts, and when it finishes,
# this script plots the duration for the events.

# Feed me a log file with rows like these:
# 2014-07-21 07:50:03,440 INFO Begin job
# 2014-07-21 07:52:50,530 INFO End job
# 2014-07-21 08:00:03,044 INFO Begin job
# 2014-07-21 08:02:02,548 INFO End job

cut -d ' ' -f 1,2 | grep -Po '^[^,]*' | xargs -ID date -d "D" +"%s" | xargs -n2 | \
  while read A; do echo "2k $A r - 60 /p" | dc; done | gnuplot -e "plot '-' with lines" -p