I'm submitting this as a solution for the FAQ. Anyone who wants to make it more elegant is quite welcome! The question came up recently in an IRC channel.
Q. How do I work out how many hours have been worked from a timesheet?
This solution takes a file in the format ISO-Date, WhiteSpace, Name
It does not take into account people who forget to log in or out apart from making sure there's an even number of dates for each user.
[Note: this later could be partly solved by splitting into days and then checking for an even number of times. Flagging days for which data was not calculable]
I changed the date format to ICal. Unfortunately, the durations are now printed as seconds.
I turned off warnings because it was complaining that $a and $b were used only once.
--------------------- #!/usr/bin/perl
use strict; use DateTime::Format::ICal; use List::Util qw(reduce);
my %users; my $ical = 'DateTime::Format::ICal';
while (<DATA>) { chomp; my ($dt, $user) = split(/\s/,$_,2); push( @{$users{$user}}, $dt ) if $dt && $user; }
for my $user ( keys %users ) { my @duration; my @dt = @{$users{$user}}; push @duration, $ical->parse_period( shift(@dt) . "/" . shift(@dt) )->duration while scalar @dt; print $ical->format_duration( reduce { $a + $b } @duration ), " $_\n" }
__DATA__ 20050101T085500 Mr Coffee 20050101T085800 BigLug 20050101T120100 BigLug 20050101T130100 BigLug 20050101T172300 Mr Coffee 20050101T172600 BigLug