Beginner Linux's Simple shell

First occupy the pit, back to complement the perfect ha

#!/bin/bash
# program:
# This program was used to stop Tomcat.
# History:
# 2016/09/11 XH First release
Pid= ' Ps-ef|grep tomcat|grep-v Grep|awk ' {print $} '
if [$pid]
Then
Echo ' Tomcat is already running. '
Else

/opt/tomcat7/bin/startup.sh
Echo ' Tomcat has just been started ... '
Tail-f/opt/tomcat7/logs/catalina.out
Fi

Pid= ' Ps-ef|grep tomcat|grep-v Grep|awk ' {print $} '
if [$pid]
Then
Echo ' Tomcat is alread running. PID is--$pid '
Else
Echo ' Tomcat has just been started ... '
Fi

Beginner Linux's Simple shell