Perl : 单行指令统计指定列中所有数值之和

见：Perl One-liners by Jeff Bay

#BEGIN和END块

ls -lAF | perl -ne 'next if /^d/; $sum += (split)[4]; END{ print "$sum\n" }'

ls -lAF | perl -ne 'BEGIN{$sum=1024} next if /^d/; $sum += (split)[4]; END{ print "$sum\n" }'

#test.txt中第一列中的最大值：

perl -ne "$i = (split)[0];$max=$i if($max<$i); END {print $max;}" < test.txt