The Eskimo operator - }{
perl -ne ‘print $_; <===> LINE: while (defined($_ = <ARGV>)) { print $_; }
therefore
# counts unique lines in the file FOO
perl -nle ‘$seen{$_}++ }{ print “$_ => $seen{$_}” for keys %seen’ FOO
or
# prints the total number of lines
perl -ne ‘}{ print $.’
