Easy to use awk

Overview

awk [parameters] 'script' var = val file (s)

Common parameters
-F specifies separator, default press space (including TAB) divided

awk '{print $1}' filename
awk -F ","  '{print $1}' filename
$n表示第几例($0表示整个行)

awk '$2 > 0 {print}'
输出第二列大于0的所有行

awk 'NF' filename
去掉空行

awk 'END{print NR}' filename
统计行数