直接上脚本，

使用$(())以及$[]进行数字计算

 数值比较：

n1 -eq n2检查n1是否等于n2         n1 -le n2检查n1是否小于等于n2

n1 -ge n2检查n1是否大于等于n2     n1 -lt n2检查n1是否小于n2

n1 -gt n2检查n1是否大于n2         n1 -ne n2检查n1是否不等于n2

#!/bin/bashnuma=1;numb=2;numc1=$(($numa - $numb));numc2=$[$numa + $numb];echo "numc1 = $numc1, numc2 = $numc2"if [ $numc1 -lt 0 ]then echo "numc1 less then 0" fiif [ $numc2 -gt 0 ]then echo "numc2 great then 0"finumd1=$(($numc1 + 9));numd2=$[$numc2 - 9];echo "numd1 = $numd1, numd2 = $numd2"if [ $numd1 -gt $numd2 ]then echo "numd1 great then numd2"else echo "numd1 not great then numd2"fi

 

 

参考：

http://www.cnblogs.com/linuxer/archive/2012/06/20/2870518.html