linux shell中获取mongodb最大连接数、内存使用情况等

./mongostat -u admin -p admin --authenticationDatabase admin -n 1 --json >> aaa.txt 

a=`cat aaa.txt`   

indma=`echo $a | awk ‘{printf("%d\n",match($0,"mapped"))}‘` 

indma1=$(($indma+8)) 

indma0=`echo $a | awk ‘{printf("%d\n",match($0,"netIn"))}‘`  

indma2=$(($indma0-4)) 

mastr=`echo ${a:$indma1:$(($indma2-$indma1))}` 

indre=`echo $a | awk ‘{printf("%d\n",match($0,"res"))}‘` 

indre1=$(($indre+5)) 

indre0=`echo $a | awk ‘{printf("%d\n",match($0,"time"))}‘`  

indre2=$(($indre0-4)) 

restr=`echo ${a:$indre1:$(($indre2-$indre1))}` 

indvs=`echo $a | awk ‘{printf("%d\n",match($0,"vsize"))}‘` 

indvs1=$(($indvs+7)) 

indvs0=${#a} 

indvs2=$(($indvs0-3)) 

vsstr=`echo ${a:$indvs1:$(($indvs2-$indvs1))}` 

indco=`echo $a | awk ‘{printf("%d\n",match($0,"conn"))}‘` 

indco1=$(($indco+6)) 

indco0=`echo $a | awk ‘{printf("%d\n",match($0,"delete"))}‘` 

indco2=$(($indco0-4)) 

costr=`echo ${a:$indco1:$(($indco2-$indco1))}`