Linux Shell Single Instance run __linux

#!/bin/sh
# **************************************************
# * * * Libraries
# **************************************************
Source/etc/profile;
Sleep 2
Date= ' date + '%f_%h:%m '

If [x$1!= "X"]
Then
Date=$1
Fi

Echo $DATE

Basedir= ' DirName $ '
CD $BASEDIR
#######################################################
tmpfile= $BASEDIR/isrunning.tmp

Echo $TMPFILE

# begin--Check if there are any other instances running to ensure that only one instance can be run at the same time

If [f $TMPFILE];then #判断临时文件是否存在www. linuxidc.com

echo "Other instance is running!" #存在表明有一个实例在运行
Exit 0 #退出本脚本的执行
Else
Touch $TMPFILE #监时文件若不存在, use your touch to create a new
chmod $TMPFILE #把临时文件属性改为只建立者可读写
Fi

#用 Trap command to set up a listener to the signal
#程序运行中当监听到信号 0,1,2,3,9,15 Deletes the temporary file and exits the script execution
#比如说, when the script ends itself, the user Ctrl + C drops, gets killed, and the terminal is closed
#系统关机或重启的情况下, you need to delete the temporary files, otherwise the script will not be able to execute
#在 Linux Shell can run trap-l check to see so the signal

Trap "Rm-f ${tmpfile}; Exit "0 1 2 3 9 15

# end--Check if there are any other instances running to ensure that only one instance can be run at the same time