awk循环语句-【AWK学习之旅】

 

AWK中两种循环语句：if-else 和 while

 

控制流语句：

1.if-else

求总数，平均值：

[root@monitor awkdir]# awk '$3>6 {n = n + 1;pay = pay + $2*$3}END{print n,pay/n}' emp.txt

4 84.375

 

语句：

awk '$3 > 6 {n = n + 1 ;pay = pay + $2 * $3}

END {if (n > 0)

print n,"employees,total pay is",pay,

"average",pay/n

else

print "no employees are paid more than $6/hour"

}

' emp.txt

 

实例：

[root@monitor awkdir]# awk '$3 > 6 {n = n + 1 ;pay = pay + $2 * $3}

> END {if (n > 0)

> print n,"employees,total pay is",pay,

> "average",pay/n

> else

> print "no employees are paid more than $6/hour"

> }

> ' emp.txt

4 employees,total pay is 337.5 average 84.375

 

2.while

语句：

awk '{

i = 1

while (i <=$3)

{printf("\t%.3f\n",$1 * (1 + $2) ^ i)

i = i + 1

}

}' w.txt

-- 

 

[root@monitor awkdir]# awk '

> {i = 1

> while (i<=$3){

> printf("\t%.2f\n",$1 * (1 + $2) ^ i)

> i = i + 1

> }

> }' w.txt

  1060.00

  1123.60

  1191.02

  1262.48

  1338.23

  1120.00

  1254.40

  1404.93

  1573.52

  1762.34

  1973.82

 

数组：

[root@monitor awkdir]# awk '{line[NR] = $0}END{i = NR ;while (i>0) {print line[i] ;i = i - 1}}' emp.txt

Susie 4.25 18

Mary 5.50 22

Mark 5.00 20

Kathy 4.00 10

Dan 3.75 0

Beth 4.00 0

[root@monitor awkdir]# awk '{line[NR] = $0}END{i = NR ;while (i>3) {print line[i] ;i = i - 1}}' emp.txt

Susie 4.25 18

Mary 5.50 22

Mark 5.00 20