Shell - 根据PID过滤进程信息

#!/bin/bash
#Function: 根据用户输入的PID，过滤出该PID所有的信息
read -p "请输入要查询的PID: " P
n=`ps -aux| awk '$2~/^'$P'$/{print $11}'|wc -l`
if [ $n -eq 0 ];then
 echo "该PID不存在！！"
 exit
fi
echo "--------------------------------"
echo "进程PID: $P"
echo "进程命令：`ps -aux| awk '$2~/^'$P'$/{print $11}'`"
echo "进程所属用户: `ps -aux| awk '$2~/^'$P'$/{print $1}'`"
echo "CPU占用率：`ps -aux| awk '$2~/^'$P'$/{print $3}'`%"
echo "内存占用率：`ps -aux| awk '$2~/^'$P'$/{print $4}'`%"
echo "进程开始运行的时刻：`ps -aux| awk '$2~/^'$P'$/{print $9}'`"
echo "进程运行的时间：`ps -aux| awk '$2~/^'$P'$/{print $10}'`"
echo "进程状态：`ps -aux| awk '$2~/^'$P'$/{print $8}'`"
echo "进程虚拟内存：`ps -aux| awk '$2~/^'$P'$/{print $5}'`"
echo "进程共享内存：`ps -aux| awk '$2~/^'$P'$/{print $6}'`"
echo "--------------------------------"