linux主机内存告警shell脚本

#!/bin/sh

ramusage=$(free | awk '/Mem/{printf("RAM Usage: %.2f
"), $3/$2*100}'| awk '{print $3}')

if [ "$ramusage" > 20 ]; then
  SUBJECT="ATTENTION: Memory Utilization is High on $(hostname) at $(date)"
  MESSAGE="/tmp/Mail.out"
  TO="2daygeek@gmail.com"
  echo "Memory Current Usage is: $ramusage%" >> $MESSAGE
  echo "" >> $MESSAGE
  echo "------------------------------------------------------------------" >> $MESSAGE
  echo "Top Memory Consuming Process Using top command" >> $MESSAGE
  echo "------------------------------------------------------------------" >> $MESSAGE
  echo "$(top -b -o +%MEM | head -n 20)" >> $MESSAGE
  echo "" >> $MESSAGE
  echo "------------------------------------------------------------------" >> $MESSAGE
  echo "Top Memory Consuming Process Using ps command" >> $MESSAGE
  echo "------------------------------------------------------------------" >> $MESSAGE
  echo "$(ps -eo pid,ppid,%mem,%Memory,cmd --sort=-%mem | head)" >> $MESSAGE
  mail -s "$SUBJECT" "$TO" < $MESSAGE
  rm /tmp/Mail.out
fi

# crontab -e
# */5 * * * * /bin/bash /opt/scripts/memory-alert.sh

# /usr/bin/free | awk '/Mem/{printf("RAM Usage: %.2f%
"), $3/$2*100}' |  awk '{print $3}' | awk '{ if($1 > 20) print $0;}' | mail -s "High Memory Alert" 1103324414@qq.com