Write daemon with shell script

Recently in doing the server, because it is all-weather operation, the server is not said to be absolutely stable, never crash never crashed anything, so even if the downtime does not matter, the key is to be able to start in time, can not affect the player experience, so

Must have daemons guarding, if the server crashes, immediately reboot to ensure that the entire business can continue to run

My startup script start.sh

#!/bin/sh
killall-9 logserver sleep
1
killall-9 gameserver
mv logserver.log/mnt/share/log/ Logserver.log.bak
mv Gameserver.log/mnt/share/log/gameserver.log.bak
Ulimit-c Unlimited
nohup./ Logserver > Logserver.log 2>&1 & Sleep
5
nohup./gameserver > Gameserver.log 2>&1 &< C9/>sleep 5
Echo Start success

Daemon Script keep.sh

#########################################################################
# File Name:keep.sh
# Author: ma6174
# mail:ma6174@163.com
# Created Time:fri 2015 07:49:46 PM CST
############################### ##########################################
#!/bin/bash
num=1
inum=1
echo $$ while
($num < 5) do
sn= ' ps-ef | grep/gameserver | grep-v grep |awk ' {print $} '
echo $sn
if ["${sn}" = ""]< c14/> #如果为空, which indicates that the process did not start
then let
"inum++"
Echo $iNum
CP gameserver.log/mnt/share/log/gameserver_$ INum.log.bak
rm gameserver.log
nohup./gameserver > Gameserver.log 2>&1 & #后台启动进程
Echo Start OK!
Else
Echo running
fi
5 done

The whole process is

1./start.sh

2./keep.sh > Keep.log 2>&1 &

Note that in keep.sh echo $$ is the output current process number, because after the shell script starts, it is difficult to check its process number, without the process number, it is difficult to kill the shell script to start the corresponding

Process, find the process number from Keep.log, kill-s 9 pid can

./keep.sh > Keep.log 2>&1 & This must be so written, because most of them are connected to Ubuntu through the terminal, directly./keep.sh can not run on the back end, if the terminal is closed, the script corresponding process is automatically killed , the daemon will not exist.

Recently tried again, and found./keep.sh > Keep.log 2>&1 & can actually run in the background, but after you turn off the terminal, you receive the HUP signal, which is still in the

Broken, can not play a effect. With Nohup also prompts a lot of errors, keep.sh this script still can't run, it seems that can not be executed on the terminal./keep.sh > Keep.log 2>&1 & only in screen session mode, for screen you can see the following documents

https://www.ibm.com/developerworks/cn/linux/l-cn-nohup/

Install screen First

Apt-get Install screen

Build a conversation again

Screen-dms Urumchi to

see this conversation again is a success

Screen-list

connected to this conversation.

Screen-r Urumchi

Then execute the keep.sh script
./keep.sh > Keep.log 2>&1 &