#!/usr/bin/perl -T

## 2008-11-14 Rob Mahurin <rob@utk.edu>
## Instructions:
##    1. save to some folder e.g. desktop
##    2. open /Applications/Utilities/Terminal.app
##    3. in a terminal, say
##		$ cd "/Users/you/Desktop" # (or wherever you put it)
##		$ chmod +x ./checkidle
##		$ ./checkidle >> datafile.txt &
##		$ exit
##    4. check datafile.txt to see the name of the frontmost application.
##       updates added every 30 seconds

use strict;
use warnings; 
use POSIX qw/strftime/; 

my @path = 
  qw[ /bin /usr/bin /sbin /usr/sbin
   ];
$ENV{PATH} = join ":", @path; 

sub idle() {
  my @ioreg = grep /idle/i, qx/ioreg -c IOHIDSystem -S/; 
  my ($idlens) = reverse split /\s+=\s+/, shift @ioreg; 
  return $idlens/1e9; 
}

sub frontmost() {
  my $script = 
    'set myapp to name of (info for (path to frontmost application))';
  open SCRIPT, "echo '$script' | osascript |"; 
  chomp(my @out = <SCRIPT>); 
  close SCRIPT; 
  return join "\n", @out;
}

my $interval = 30; 
while (1) {
  printf "%s\t%s\t%s\n", 
    $$, strftime("%F %T\t%s", localtime), frontmost(), "\n", 
    if idle() < $interval; 
  sleep $interval; 
}