在本教程中，我将显示一个shell脚本，用于检查每个程序或者Linux上的应用程序的内存使用情况。
脚本输出在Linux中运行的每个程序的共享和私有内存。
由于内存计算有点复杂，因此此shell脚本尝试最佳地查找更准确的结果。

此脚本使用2个文件即"/proc/../status"(获取进程的名称)和"/proc/../smaps"，以获取进程的内存统计信息。
然后脚本将所有数据转换为KB，MB，GB。
此外，请确保安装BC命令。

shell脚本检查内存使用情况

检查以下脚本，该脚本计算内存使用和打印输出。

#!/bin/bash
# Make sure only root can run our script
if [ "$(id -u)" != "0" ]; then
echo "This script must be run as root" 1>&2
exit 1
fi
### Functions
#This function will count memory statistic for passed PID
get_process_mem ()
{
PID=
#we need to check if 2 files exist
if [ -f /proc/$PID/status ];
then
if [ -f /proc/$PID/smaps ];
then
#here we count memory usage, Pss, Private and Shared = Pss-Private
Pss=`cat /proc/$PID/smaps | grep -e "^Pss:" | awk '{print }'| paste -sd+ | bc `
Private=`cat /proc/$PID/smaps | grep -e "^Private" | awk '{print }'| paste -sd+ | bc `
#we need to be sure that we count Pss and Private memory, to avoid errors
if [ x"$Rss" != "x" -o x"$Private" != "x" ];
then
let Shared=${Pss}-${Private}
Name=`cat /proc/$PID/status | grep -e "^Name:" |cut -d':' -f2`
#we keep all results in bytes
let Shared=${Shared}*1024
let Private=${Private}*1024
let Sum=${Shared}+${Private}
echo -e "$Private + $Shared = $Sum \t $Name"
fi
fi
fi
}
#this function make conversion from bytes to Kb or Mb or Gb
convert()
{
value=
power=0
#if value 0, we make it like 0.00
if [ "$value" = "0" ];
then
value="0.00"
fi
#We make conversion till value bigger than 1024, and if yes we divide by 1024
while [ $(echo "${value} > 1024"|bc) -eq 1 ]
do
value=$(echo "scale=2;${value}/1024" |bc)
let power=$power+1
done
#this part get b,kb,mb or gb according to number of divisions
case $power in
0) reg=b;;
1) reg=kb;;
2) reg=mb;;
3) reg=gb;;
esac
echo -n "${value} ${reg} "
}
#to ensure that temp files not exist
[[ -f /tmp/res ]] && rm -f /tmp/res
[[ -f /tmp/res2 ]] && rm -f /tmp/res2
[[ -f /tmp/res3 ]] && rm -f /tmp/res3
#if argument passed script will show statistic only for that pid, of not – we list all processes in /proc/#and get statistic for all of them, all result we store in file /tmp/res
if [ $# -eq 0 ]
then
pids=`ls /proc | grep -e [0-9] | grep -v [A-Za-z] `
for i in $pids
do
get_process_mem $i >> /tmp/res
done
else
get_process_mem >> /tmp/res
fi
#This will sort result by memory usage
cat /tmp/res | sort -gr -k 5 > /tmp/res2
#this part will get uniq names from process list, and we will add all lines with same process list
#we will count nomber of processes with same name, so if more that 1 process where will be
# process(2) in output
for Name in `cat /tmp/res2 | awk '{print }' | sort | uniq`
do
count=`cat /tmp/res2 | awk -v src=$Name '{if (==src) {print }}'|wc -l| awk '{print }'`
if [ $count = "1" ];
then
count=""
else
count="(${count})"
fi
VmSizeKB=`cat /tmp/res2 | awk -v src=$Name '{if (==src) {print }}' | paste -sd+ | bc`
VmRssKB=`cat /tmp/res2 | awk -v src=$Name '{if (==src) {print }}' | paste -sd+ | bc`
total=`cat /tmp/res2 | awk '{print }' | paste -sd+ | bc`
Sum=`echo "${VmRssKB}+${VmSizeKB}"|bc`
#all result stored in /tmp/res3 file
echo -e "$VmSizeKB + $VmRssKB = $Sum \t ${Name}${count}" >>/tmp/res3
done
#this make sort once more.
cat /tmp/res3 | sort -gr -k 5 | uniq > /tmp/res
#now we print result , first header
echo -e "Private \t + \t Shared \t = \t 内存 used \t Program"
#after we read line by line of temp file
while read line
do
echo $line | while read a b c d e f
do
#we print all processes if Ram used if not 0
if [ $e != "0" ]; then
#here we use function that make conversion
echo -en "`convert $a` \t $b \t `convert $c` \t $d \t `convert $e` \t $f"
echo ""
fi
done
done < /tmp/res
#this part print footer, with counted Ram usage
echo "--------------------------------------------------------"
echo -e "\t\t\t\t\t\t `convert $total`"
echo "========================================================"
# we clean temporary file
[[ -f /tmp/res ]] && rm -f /tmp/res
[[ -f /tmp/res2 ]] && rm -f /tmp/res2
[[ -f /tmp/res3 ]] && rm -f /tmp/res3

shell脚本输出

我已将此脚本命名为"Memstat.sh"，并通过运行脚本如下查找输出：

[root@centos-cluster-node1 ~]# ./memstat.sh
Private + Shared = 内存 used Program
36.26 mb + 268.00 kb = 36.52 mb python
20.49 mb + 238.00 kb = 20.72 mb iscsiuio
4.78 mb + 451.00 kb = 5.22 mb rgmanager(2)
3.62 mb + 283.00 kb = 3.90 mb NetworkManager
2.53 mb + 1.36 mb = 3.89 mb sshd(3)
2.30 mb + 355.00 kb = 2.64 mb multipathd
984.00 kb + 314.00 kb = 1.26 mb pickup
976.00 kb + 316.00 kb = 1.26 mb master
1.07 mb + 21.00 kb = 1.09 mb rsyslogd
804.00 kb + 240.00 kb = 1.01 mb modem-manager
904.00 kb + 40.00 kb = 944.00 kb pcscd
804.00 kb + 33.00 kb = 837.00 kb ricci
788.00 kb + 38.00 kb = 826.00 kb dbus-daemon
660.00 kb + 32.00 kb = 692.00 kb crond
536.00 kb + 69.00 kb = 605.00 kb rpc.statd
528.00 kb + 46.00 kb = 574.00 kb init
216.00 kb + 357.00 kb = 573.00 kb saslauthd(5)
544.00 kb + 21.00 kb = 565.00 kb wpa_supplicant
484.00 kb + 72.00 kb = 556.00 kb mingetty(6)
316.00 kb + 58.00 kb = 374.00 kb rpcbind
116.00 kb + 237.00 kb = 353.00 kb memstat.sh
328.00 kb + 13.00 kb = 341.00 kb auditd
248.00 kb + 84.00 kb = 332.00 kb hald-runner
312.00 kb + 8.00 kb = 320.00 kb oddjobd
216.00 kb + 81.00 kb = 297.00 kb hald-addon-stor
196.00 kb + 88.00 kb = 284.00 kb hald-addon-inpu
272.00 kb + 4.00 kb = 276.00 kb rpc.idmapd
176.00 kb + 52.00 kb = 228.00 kb hald-addon-acpi
-------------------------------------------------------
98.57 mb
========================================================
[root@centos-cluster-node1 ~]#