awk认知
awk 执行模式
所需文件： 1.pattern { action }
$3 == 0 { print $1 }
//awk '$3 >0 { print $1, $2 * $3 }' emp.data
//awk '$3 == 0 { print $1 }' file1 file2
基础输出print，字段数量NF，行号NR
{ print "total pay for", $1, "is", $2 * $3 }
// awk '{ print NR,"name ",$1,"salary ",$2*$3,"字段数量",NF}' emp.data
逻辑运算
NF != 3 { print $0, "number of fields is not equal to 3" }
$2 < 3.35 { print $0, "rate is below minimum wage" }
$2 > 10 { print $0, "rate exceeds $10 per hour" }
$3 < 0 { print $0, "negative hours worked" }
$3 > 60 { print $0, "too many hours worked" }
BEGIN与END
awk 'BEGIN{print "Name","path","hours"}
{ print $1,$2,$3}
END{ {print "total is",pay}{print "average is",pay/NR}}' emp.data
变量应用
awk '{ nc = nc + length($0) + 1
nw = nw + NF
}
END { print NR, "lines,", nw, "words,", nc, "characters" }'
ifelse while for array
awk '
{
nc = nc + length($0) + 1
nw = nw + NF
arr[1]="hello the world";
}
{
for(i=1;i<5;i++)
{
{print "now i is" ,i}
{
if(i>3){print "my name is zylg"}
else {print "hello zylg"}
}
while(1)
{
{print "exit"}
break;
}
{
print arr[1]
}
}
}
END { print NR, "lines,", nw, "words,", nc, "characters" }' ~/removesoft
