perl -MTime::Piece -lE 'my $lt=localtime; my $ty=$lt->year ; while(<>){next unless m/(\w+) +(\d+) +(\d+:\d+:\d+)/;\
my $t=Time::Piece->strptime("$ty $1 $2 $3","%Y %b %d %H:%M:%S"); print q{#####} ; print ; print $lt ; print $t ; print $lt-$t }' log file
#####
Jun 6 00:07:41 xxxxx
Thu Aug 9 03:45:48 2012
Wed Jun 6 00:07:41 2012
5510287
#####
Aug 8 00:14:34 yyyyy
Thu Aug 9 03:45:48 2012
Wed Aug 8 00:14:34 2012
66674
#####
Aug 8 00:16:26 zzzzz
Thu Aug 9 03:45:48 2012
Wed Aug 8 00:16:26 2012
66562
#####
Aug 8 22:15:14 zzzzz
Thu Aug 9 03:45:48 2012
Wed Aug 8 22:15:14 2012
-12566

うちの環境だとTime::Pieceオブジェクトの除算が変だ。なんで？