awk 统计平均 最大 最小值

#!/bin/awk -f

BEGIN	{
    min=0
    max=0
    diff=0
    avg=0
    sum=0
    cnt=0
}
{
   # cals diff find max min avg
    diff=$6-$4
    sum=sum+diff 
    cnt=cnt+1

    if(NR ==  1){
        min = diff
        max = diff
    }

    if(min > diff){
        min = diff
    }
    if(max < diff){
        max = diff
    }
}
END	{
    avg=sum/cnt
    printf("min: "min" max: "max" avg: "avg" cnt: "cnt"n")
}