如何编写 shell 脚本以从 sar 报告中查找 ram 利用率的最小最大值和平均值

Question

我编写了一个 shell 脚本来从 sar 报告中为命令 sar -r -f 查找平均值、最小值和最大值，如下所示

MIN1=`sar -r -f |awk '{print $5}'|grep -v '%memused'|awk 'min=="" || $0 < min {min=$0} END{ print min}'`

MAX1=`sar -r -f |awk '{print $5}'|grep -v '%memused'|grep -v '_x86_64_'|grep -v '86327'|awk 'min=="" || $0 > min {min=$0} END{ print min}'`

AVG1=`sar -r -f |awk '{print $5}'|grep -v '%memused'|grep -v '_x86_64_'|grep -v '86327'|awk '{total+=$0} END {print total/NR}'`

echo Minimum value is $MIN1 : average value is $AVG1 : maximum value is $MAX1

sar -r -f 命令 o/p:

Linux 2.6.32-431.el6.x86_64 (servername)   11/03/2017      _x86_64_        (4 CPU)

12:00:01 AM kbmemfree kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit

Average:       315191  32697953     99.05     86327  16937751  25889218     53.25

脚本输出：

Minimum value is 95.50 : average value is 868.053 : maximum value is 86327

预期输出：

Minimum value is 95 : average value is 96 : maximum value is 97

我已使用出现在最后一列中的grep -v 86327 跳过了该值，但因为它每次输出都会发生变化。

Answer 1

关注awk 可能对您有所帮助。

sar -r -f |  awk '
FNR>1&&!/memused/{
 max=max>$5?max:$5;
 min=min>$5?$5:(min?min:$5);
 sum+=$5}
END{
print "Minimum:",min,"Average:",(sum/FNR),"Maximum:",max
}'

编辑：现在也为代码添加解释。

sar -r -f |  awk '      ## Sending sar standard output as a standard input by pipe to awk command.
FNR>1&&!/memused/{      ## checking if line number is greater than and not having string memused in it then do following.
 max=max>$5?max:$5;     ## creating a variable named max and checking if max variable value is greater than 5th field then keep it as max else keep it as 5th field to get the maximum values.
 min=min>$5?$5:(min?min:$5); ##creating a variable named min and checking if min value is greater than 5th field if yes then change its value to $5 or check if min is there keep its value to min or if min is NULL then keep it as $5 value.
 sum+=$5}               ## creating variable named sum and adding its value to itself along with 5th fields value.
END{
print "Minimum:",min,"Average:",(sum/FNR),"Maximum:",max ##Printing string minimum and min value similarly with avg and maximum too.
}'