test.txt文件内容:
9
11
35
21
42
118
求最大值:
awk 'BEGIN {max = 0} {if ($1+0 > max+0) max=$1} END {print "Max=", max}' test.txt
Max= 118
求最小值:
awk 'BEGIN {min = 65536} {if ($1+0 < min+0) min=$1} END {print "Min=", min}' test.txt
Min= 9
求和:
cat test.txt|awk '{sum+=$1} END {print "Sum= ", sum}'
Sum= 236
求平均值:
cat test.txt|awk '{sum+=$1} END {print "Avg= ", sum/NR}'
Avg= 39.3333
求最大值(错误的求法):
cat test.txt|awk 'BEGIN {max = 0} {if ($1>max) max=$1 fi} END {print "Max=", max}'
Max= 9
求最小值(错误的求法):
cat test.txt|awk 'BEGIN{min = 65536}{if ($1<min) min=$1 fi}END{print "Min=", min}'
Min= 11
求最大值(正确的求法):
cat test.txt|awk 'BEGIN {max = 0} {if ($1+0>max+0) max=$1 fi} END {print "Max=", max}'
Max= 118
求最小值(正确的求法):
cat test.txt|awk 'BEGIN{min = 65536}{if ($1+0<min+0) min=$1 fi}END{print "Min=", min}'
Min= 9
awk默认按照字符串比较的,如果要比较数值,需要先强制类型转换,即 $1+0,转换成整数。
Reference:
http://www.ahlinux.com/shell/4072.html
http://www.bkjia.com/LINUXxt/956509.html