So for example, when a user netcats to port 7896, a script which asks for a user input will run.
Try like this. Create listener script
$ cat listener
#!/bin/bash
port=7896
input=$(nc -l -p $port) || exit $?
./test ${input:-empty}
Create test script
$ cat test
#!/bin/bash
echo $1
./listener
Run listener
./listener
And in another terminal run
port=7896
nc -q0 localhost $port 2> /dev/null <<< "hello"
Here's a server that executes foo.sh when someone connects.
server.sh
#!/bin/bash
while [[ 1 ]]; do
ncat -l -p 7896 -e foo.sh
done
foo.sh
#!/bin/bash
echo -n 'prompt> '
while IFS= read -r cmd
do
echo "got >$cmd<"
echo -n 'prompt> '
done
A sample session:
$ ncat localhost 7896
prompt> Hello world
got >Hello world<
prompt> <CTRL-D>
$
I have a script with this name : Run.sh
I run this script with this command :
./run.sh
I don't like stop this script but this script Suddenly stops and need run again.
I need a script to check it , if my run.sh stopped , run it again.
this is run.sh codes:
#!/usr/bin/env bash
install() {
sudo apt-get update
sudo apt-get upgrade
}
if [ "$1" = "install" ]; then
install
else
if [ ! -f ./tg/tgcli ]; then
echo "tg not found"
echo "Run $0 install"
exit 1
fi
#sudo service redis-server restart
#./tg/tgcli -s ./bot/bot.lua -l 1 -E $#
./tg/tgcli -s ./bot/bot.lua $#
fi
And i want run this script at boot (with screen or tmux) if my server restart
i have Ubuntu 16.04 version
Thank you Ljm Dullaart
Can you help me about this ?
You should not need to run the complete bash script again. Changing
./tg/tgcli -s ./bot/bot.lua $#
to
while :; do
./tg/tgcli -s ./bot/bot.lua $#
done
will restart bot.lua everytime it exits.
You can check if your run.sh is running and re-run it if stopped with a single command:
$ if ! pgrep run.sh ;then /path/to/run.sh;fi
If script runs pgrep will return exit status 0 = success and will print the pid of run.sh
If script does not run pgrep will return exit status 1 and then script will be called.
You can also use pgrep inst.sh >/dev/null to "mute" pgrep in case script is running.
Here is my code:
#!/bin/bash
ps cax | grep testing > /dev/null
while [ 1 ]
do
if [ $? -eq 0 ]; then
echo "Process is running."
sleep 10
else
nohup ./testing.sh &
sleep 10
fi
done
I run it as nohup ./script.sh &
and it said nohup: failed to run command './script.sh': No such file or directory
What is wrong?
The file script.sh simply does not exist in the directory that you are issuing the command from.
If it did exist and was not executable you would get:
`nohup: failed to run command ‘./script.sh’: Permission denied
For each newly created scripts on Linux, you should first change the permission as you can see the permission details by using
ls -lah
The following content may help you:
#!/bin/bash
while [ 1 ];
do
date=`date`
pid=`ps -ef | grep "your process" | grep -v grep | awk -F' ' '{print $2}'`
if [[ -n $pid ]]; then
echo "$date - processID $pid is running."
else
echo "$date - the process is not running"
# script to restart your process
say: start the process
fi
sleep 5m
done
Make sure your script is saved as script.sh
and your executing nohup ./script.sh & from the same directory in which script.sh.
Also you can give executable permission for script.sh by
chmod 776 script.sh
or
nohup ./script.sh &
Run as
nohup sh ./script.sh &
I have a process that fails regularly & sometimes starts duplicate instances..
When I run:
ps x |grep -v grep |grep -c "processname"
I will get:
2
This is normal as the process runs with a recovery process..
If I get
0
I will want to start the process
if I get:
4
I will want to stop & restart the process
What I need is a way of taking the result of ps x |grep -v grep |grep -c "processname"
Then setup a simple 3 option function
ps x |grep -v grep |grep -c "processname"
if answer = 0 (start process & write NOK & Time to log /var/processlog/check)
if answer = 2 (Do nothing & write OK & time to log /var/processlog/check)
if answer = 4 (stot & restart the process & write NOK & Time to log /var/processlog/check)
The process is stopped with
killall -9 process
The process is started with
process -b -c /usr/local/etc
My main problem is finding a way to act on the result of ps x |grep -v grep |grep -c "processname".
Ideally, I would like to make the result of that grep a variable within the script with something like this:
process=$(ps x |grep -v grep |grep -c "processname")
If possible.
Programs to monitor if a process on a system is running.
Script is stored in crontab and runs once every minute.
This works with if process is not running or process is running multiple times:
#! /bin/bash
case "$(pidof amadeus.x86 | wc -w)" in
0) echo "Restarting Amadeus: $(date)" >> /var/log/amadeus.txt
/etc/amadeus/amadeus.x86 &
;;
1) # all ok
;;
*) echo "Removed double Amadeus: $(date)" >> /var/log/amadeus.txt
kill $(pidof amadeus.x86 | awk '{print $1}')
;;
esac
0 If process is not found, restart it.
1 If process is found, all ok.
* If process running 2 or more, kill the last.
A simpler version. This just test if process is running, and if not restart it.
It just tests the exit flag $? from the pidof program. It will be 0 of process is running and 1 if not.
#!/bin/bash
pidof amadeus.x86 >/dev/null
if [[ $? -ne 0 ]] ; then
echo "Restarting Amadeus: $(date)" >> /var/log/amadeus.txt
/etc/amadeus/amadeus.x86 &
fi
And at last, a one liner
pidof amadeus.x86 >/dev/null ; [[ $? -ne 0 ]] && echo "Restarting Amadeus: $(date)" >> /var/log/amadeus.txt && /etc/amadeus/amadeus.x86 &
This can then be used in crontab to run every minute like this:
* * * * * pidof amadeus.x86 >/dev/null ; [[ $? -ne 0 ]] && echo "Restarting Amadeus: $(date)" >> /var/log/amadeus.txt && /etc/amadeus/amadeus.x86 &
cccam oscam
I adopted the #Jotne solution and works perfectly! For example for mongodb server in my NAS
#! /bin/bash
case "$(pidof mongod | wc -w)" in
0) echo "Restarting mongod:"
mongod --config mongodb.conf
;;
1) echo "mongod already running"
;;
esac
I have adopted your script for my situation Jotne.
#! /bin/bash
logfile="/var/oscamlog/oscam1check.log"
case "$(pidof oscam1 | wc -w)" in
0) echo "oscam1 not running, restarting oscam1: $(date)" >> $logfile
/usr/local/bin/oscam1 -b -c /usr/local/etc/oscam1 -t /usr/local/tmp.oscam1 &
;;
2) echo "oscam1 running, all OK: $(date)" >> $logfile
;;
*) echo "multiple instances of oscam1 running. Stopping & restarting oscam1: $(date)" >> $logfile
kill $(pidof oscam1 | awk '{print $1}')
;;
esac
While I was testing, I ran into a problem..
I started 3 extra process's of oscam1 with this line:
/usr/local/bin/oscam1 -b -c /usr/local/etc/oscam1 -t /usr/local/tmp.oscam1
which left me with 8 process for oscam1. the problem is this..
When I run the script, It only kills 2 process's at a time, so I would have to run it 3 times to get it down to 2 process..
Other than killall -9 oscam1 followed by /usr/local/bin/oscam1 -b -c /usr/local/etc/oscam1 -t /usr/local/tmp.oscam1, in *)is there any better way to killall apart from the original process? So there would be zero downtime?
If you changed awk '{print $1}' to '{ $1=""; print $0}' you will get all processes except for the first as a result. It will start with the field separator (a space generally) but I don't recall killall caring. So:
#! /bin/bash
logfile="/var/oscamlog/oscam1check.log"
case "$(pidof oscam1 | wc -w)" in
0) echo "oscam1 not running, restarting oscam1: $(date)" >> $logfile
/usr/local/bin/oscam1 -b -c /usr/local/etc/oscam1 -t /usr/local/tmp.oscam1 &
;;
2) echo "oscam1 running, all OK: $(date)" >> $logfile
;;
*) echo "multiple instances of oscam1 running. Stopping & restarting oscam1: $(date)" >> $logfile
kill $(pidof oscam1 | awk '{ $1=""; print $0}')
;;
esac
It is worth noting that the pidof route seems to work fine for commands that have no spaces, but you would probably want to go back to a ps-based string if you were looking for, say, a python script named myscript that showed up under ps like
root 22415 54.0 0.4 89116 79076 pts/1 S 16:40 0:00 /usr/bin/python /usr/bin/myscript
Just an FYI
The 'pidof' command will not display pids of shell/perl/python scripts. So to find the process id’s of my Perl script I had to use the -x option i.e. 'pidof -x perlscriptname'
I cannot get case to work at all.
Heres what I have:
#! /bin/bash
logfile="/home/name/public_html/cgi-bin/check.log"
case "$(pidof -x script.pl | wc -w)" in
0) echo "script not running, Restarting script: $(date)" >> $logfile
# ./restart-script.sh
;;
1) echo "script Running: $(date)" >> $logfile
;;
*) echo "Removed duplicate instances of script: $(date)" >> $logfile
# kill $(pidof -x ./script.pl | awk '{ $1=""; print $0}')
;;
esac
rem the case action commands for now just to test the script. the above pidof -x command is returning '1', the case statement is returning the results for '0'.
Anyone have any idea where I'm going wrong?
Solved it by adding the following to my BIN/BASH Script:
PATH=$PATH:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
In case you're looking for a more modern way to check to see if a service is running (this will not work for just any old process), then systemctl might be what you're looking for.
Here's the basic command:
systemctl show --property=ActiveState your_service_here
Which will yield very simple output (one of the following two lines will appear depending on whether the service is running or not running):
ActiveState=active
ActiveState=inactive
And if you'd like to know all of the properties you can get:
systemctl show --all your_service_here
If you prefer that alphabetized:
systemctl show --all your_service_here | sort
And the full code to act on it:
service=$1
result=`systemctl show --property=ActiveState $service`
if [[ "$result" == 'ActiveState=active' ]]; then
echo "$service is running" # Do something here
else
echo "$service is not running" # Do something else here
fi
If you are using CentOS, no need to write a script and set cron job. Here is one of the smartest ways to ensure systemd services restart on failure.
Make following changes to /usr/lib/systemd/system/mariadb.service
Then under the [Service] section in the file, add the following 2 lines:
Restart=always
RestartSec=3
After saving the file we need to reload the daemon configurations to ensure systemd is aware of the new file
systemctl daemon-reload
Read the following link for the complete steps -
https://jonarcher.info/2015/08/ensure-systemd-services-restart-on-failure/
We have a Linux Daemon in c and a bash script to start it. The daemon sometimes fail to start because of some configuration file errors but the script reports the daemon was started successfully. A snippet of the script is shown as below, could someone tell me what's wrong with the script?
...
case "$1" in
start)
echo -n "Starting Demo Daemon: "
sudo -u demouser env DEMO_HOME=$DEMO_HOME /usr/local/demouser/bin/democtl startup > /dev/null 2> /dev/null
if [ "$?" = "0" ]; then
echo_success
else
echo_failure
fi
echo
;;
...
Thanks!
I feel there is nothing wrong with the script,it is the reponsibility of daemon to return non zero exit status if failed to start properly and based on those the script will display the message.(which i think it does)
You can add following line in your script to get running status of your Linux Daemon
status=`ps -aef |grep "\/usr\/local\/demouser\/bin\/democtl" |grep -v grep|wc -l`
if [ "$status" = "1" ]; then
echo_success
else
echo_failure
fi