错误：预期的整数表达式

Question

我编写了一个脚本来确定服务器上的平均负载，如下所示：

#!/bin/bash

loadavg=`top -b -n1 | grep -i load | awk -F, '{print$4}'| awk -F: '{print $2}'`

if [ "${loadavg}" -le  1 ]
then
echo "OK - Load Average = ${loadavg} | Load_Average=${loadavg}"
exit 0;
elif [ "${loadavg}" -gt 1 ] && [ "${loadavg}" -le 2 ]
then
echo "WARNING - Load Average = ${loadavg} | Load_Average=${loadavg}"
exit 1;
elif [ "${loadavg}" -gt 2 ]
then
echo "CRITICAL - Load Average = ${loadavg} | Load_Average=${loadavg}"
exit 2;
else
echo "UNKNOWN - Load Average = NaN | Load_Average=NaN"
fi

执行脚本时，显示以下错误：

./loadavg.sh
./loadavg.sh: line 5: [:  0.06: integer expression expected
./loadavg.sh: line 9: [:  0.06: integer expression expected
./loadavg.sh: line 13: [:  0.06: integer expression expected
UNKNOWN - Load Average = NaN | Load_Average=NaN

Answer 1

bash（与ksh93or zsh¹相反）不能进行浮点运算。awk可以，所以你可以在awk.

此外，您不需要使用top（并等待 1 秒）来获取负载。获取负载的规范方法是从uptime.

uptime | awk '{load=+$(NF-2)}
  load > 2 {print "CRITICAL: " load; exit 2}
  load > 1 {print "WARNING: " load; exit 1}
  {print "OK: " load; exit 0}
  END {if (!NR) {print "UNKNOWN"; exit 3}'
exit

^{1在zsh虽然，你需要使用(( loadavg > 2 ))，而不是[ "$loadavg" -gt 2 ]语法比较非整数}