使用模式，结构化命令

#!/bin/bash
#正则表达式

gawk 'BEGIN{FS=","} 
/11/{print $1}
' test

#if-else语句
gawk '{
if($1 > 20)
{
    x=$1*20
    print x
}
else
{
    x=$1/2
    print x
}
}' test

#while 语句
gawk '{
total = 0
i=1
while(i<4)
{
    total+=$i
    i++
}
avg = total/3
print "Average:".avg
}' test


#do-while语句
gawk '{
total=0
i=1
do
{
    total += $i
    i++
}while(total < 150)
print total }' test


#for语句
gawk '{
total = 0
for (i=1; i<4; i++)
{
    total+=$i
}
avg = total/3
print "Average:".avg
}' test