linux系统中awk命令求一列值的最大值、最小值、和及平均值

1、最大值

[root@centos7 test]# cat a.txt
4 2 8
6 4 9
2 7 5
3 5 7
[root@centos7 test]# awk 'BEGIN{max = 0}{if($1 > max) max = $1}END{print max}' a.txt
6
[root@centos7 test]# awk 'BEGIN{max = 0}{if($2 > max) max = $2}END{print max}' a.txt
7
[root@centos7 test]# awk 'BEGIN{max = 0}{if($3 > max) max = $3}END{print max}' a.txt
9

2、最小值

[root@centos7 test]# cat a.txt
4 2 8
6 4 9
2 7 5
3 5 7
[root@centos7 test]# awk 'BEGIN{min = 999999999}{if($1 < min) min = $1}END{print min}' a.txt
2
[root@centos7 test]# awk 'BEGIN{min = 999999999}{if($2 < min) min = $2}END{print min}' a.txt
2
[root@centos7 test]# awk 'BEGIN{min = 999999999}{if($3 < min) min = $3}END{print min}' a.txt
5

3、求和

[root@centos7 test]# cat a.txt
4 2 8
6 4 9
2 7 5
3 5 7
[root@centos7 test]# awk '{sum += $1}END{print sum}' a.txt
15
[root@centos7 test]# awk '{sum += $2}END{print sum}' a.txt
18
[root@centos7 test]# awk '{sum += $3}END{print sum}' a.txt
29

 4、求平均值

[root@centos7 test]# cat a.txt
4 2 8
6 4 9
2 7 5
3 5 7
[root@centos7 test]# awk '{sum += $1}END{print sum/NR}' a.txt
3.75
[root@centos7 test]# awk '{sum += $2}END{print sum/NR}' a.txt
4.5
[root@centos7 test]# awk '{sum += $3}END{print sum/NR}' a.txt
7.25