crontab can not running shell script - shell

I have a script, when i write it in /etc/crontab it works, but it does not work in the following conditions:
crontab -l > wakeup
echo "20 15 * * thu root CALLERID=755 LIST=4001 FILE=hello-world /bin/sh /usr/local/bin/asterisk_wakeup_call.sh" >> wakeup
crontab wakeup
rm wakeup
asterisk_wakeup_call.sh
for element in $LIST
do
/usr/bin/touch /tmp/$element.call
/bin/cat >> /tmp/$element.call <<-EOF
Channel: SIP/${element}
Application: Playback
Data:${FILE}
Callerid: ${CALLERID}
EOF
/bin/mv /tmp/$element.call /var/spool/asterisk/
/bin/mv /var/spool/asterisk/$element.call /var/spool/asterisk/outgoing
done
I should add:
The cron daemon is running
The files have permission
please help me to find the mistake.

Related

Can't run a shell script every 24 hours

I have written a shell script that runs some commands. I have added a logic to run this script once every 24 hours. But it runs once and then doesn't run.
The script is as below:
#!/bin/bash
while true; do
cd /home/ubuntu/;
DATE=`date '+%Y-%m-%d'`;
aws s3 cp --recursive "/home/ubuntu/" s3://bucket_name/$DATE/;
rm -r -f ./*;
# sleep 24 hours
sleep $((24 * 60 * 60))
done
Why does it not run once every 24 hours ? I do not get any errors when the script runs. The copy takes about 10 mins.
The good practice is to protect your script againt multirunning.
In this case, you can be sure that only 1 instance is running.
#!/bin/bash
LOCKFILE=/tmp/block_file
if ( set -o noclobber; echo "$$" > "$LOCKFILE") 2> /dev/null;
then
trap 'rm -f "$LOCKFILE"; exit $?' INT TERM EXIT
while true; do
cd /home/ubuntu/;
DATE=`date '+%Y-%m-%d'`;
aws s3 cp --recursive "/home/ubuntu/" s3://bucket_name/$DATE/;
rm -r -f ./*;
# sleep 24 hours
sleep $((24 * 60 * 60))
done
rm -f "$LOCKFILE"
trap - INT TERM EXIT
else
echo "Warning. Script is already running!"
echo "Block by PID $(cat $LOCKFILE) ."
exit
fi
You can run a script immune to hangups.
nohup is a UNIX utility that runs the specified command ignoring communication loss signals (SIGHUP). Thus, the script will continue to work in the background even after the user logs out.
nohup ./yourscript.sh
The created file /tmp/block_file will safe runned script against multirunning. To complete it press ctrl+c or run kill -11 pidofyourscript in terminal, in this way /tmp/block_file will be deleted.
The output of script puts on file nohup.out.
To run in background (preferred way):
nohup ./yourscript.sh &
Your script is probably killed due to inactivity, or when you exit the shell. The proper way to do this is use cron, as #Christian.K mentioned. See https://help.ubuntu.com/community/CronHowto

process not starting completely, when called inside crontab

I have a script( let us call it watcher) which checks for a particular process if it's not running the watcher will start the process through a script.
I run this watcher in crontab at every minute. Now the problem is that it's not working in crontab but working if I run the watcher directly from the command line.
suppose the watcher start a script file called serverA.
ServerA code
echo -n "Starting $NAME: "
# start network server
start-stop-daemon --start --background --make-pidfile \
--pidfile $net_server_pidfile --startas /bin/bash -- -c "exec $angel $net_server \
-c $conf_file --lora-eui $lora_eui --lora-hw-1 $lora_hw --lora-prod-1 $lora_id \
--lora-path $run_dir --db $conf_db \
--noconsole >> $net_server_log 2>&1"
sleep 2
# start packet forwarder
/usr/sbin/start-stop-daemon --chdir $run_dir/1 --start --background --make-pidfile \
--pidfile $pkt_fwd_pidfile --exec $angel -- $pkt_fwd
renice -n -20 -p $(pgrep lora-network-se)
renice -n -20 -p $(pgrep $(basename $pkt_fwd))
echo "OK"
Now if i run watcher from directly the serverA will echo output Starting something then after sometime it continues with OK at the end.
But in crontab logs i dont see the OK, because of which the service never completes and serverA never starts.
watcher.sh
else
echo "$(date) do something, no packet forwader runnig"
exec /etc/init.d/lora-network-server start
fi
I think that you need to check difference of run time environments based terminal or not.
Firstly Check the lora-network-server whether depend on shell environments, such as JAVA_HOME or PATH (e.g. can execute the binary without absolute path of binary).
If it has different setting, it make same shell environments.
For exmaple, how to diff between cron env and runtime env.
runtime
$ env | tee ./runtime.output
cron
$ crontab <<EOF
* * * * * /bin/env > /path/to/cron.output 2>&1
EOF
Above cron output will create after 1 minute, and remove the cront after test.
you can check the variables onto cron.output and runtime.output
I hope this will help you.
Cron runs with a mostly empty environment. Are you setting all necessary environment variables in your scripts?

Simple daemon process in Ubuntu

I want to start a simple daemon process in Ubuntu, which will write the current time to log file every 5 seconds.
start-stop-daemon --start --user root --make-pidfile --pidfile /home/manjesh/test.pid --exec /home/manjesh/simplescript.sh
simplescript.sh
#!/bin/bash
echo $(date)" SNMP Monitoring and Log aggregator service " >> /home/manjesh/log.txt
while true
do
echo $(date) >> /home/dcae/snmp-service/log
sleep 5
done
When I execute the command it says "No such file or directory even if the file do exist"
Any help will be appreciated. Thanks.
The way I would do this is to use a cron job that triggers every minute and calls a script that writes the time every 5 seconds, like this:
Cron:
* * * * * /usr/local/bin/script >/dev/null 2>&1
Script:
#!/bin/bash
mkdir -p /home/dcae/snmp-service/
i="0"
while [ $i -lt 12 ]
do
echo $(date) >> /home/dcae/snmp-service/log
i=$[$i+1]
sleep 5
done
The problem was I had created a file in Windows and moved to Ubuntu, and there was a formatting problem
-bash: ./my_script: /bin/bash^M: bad interpreter: No such file or directory

piping cronjob output to logger prevents it from exiting

A small example to show my problem. The default shell is bash but my scripts use sh. This is the crontab line which I added for root (start.sh has to be run as root):
*/1 * * * * "/home/mydir/start.sh" "/home/mydir" 2>&1 | logger
Contents of start.sh:
#!/bin/sh
nohup "$1"/start_sleeper.sh "$1" &
Contents of start_sleeper.sh:
#!/bin/sh
/usr/bin/python -u "$1"/sleeper.py "$1" >> "$1"/log &
sleeper.py prints a message every 5 seconds which is appended to log in the same directory. It should continue to run in the background while start.sh can proceed and then exit. It indeed proceeds with any code below the nohup "$1"/sta.. line, but it does not exit for some reason:
pgrep -lf sleeper.py
22303 /usr/bin/python -u /home/mydir/sleeper.py /home/mydir
pgrep -lf start.sh
22296 /bin/sh -c "/home/mydir/start.sh" "/home/mydir" 2>&1 | logger
When I omit 2>&1 | logger from crontab then start.sh exits. Is there any way in this case to pipe output to the logger without start.sh remaining opened?
My solution was to add /bin/kill -SIGHUP $PPID at the end of start.sh. The cronline spawns 2 processes, one for the actual start.sh and one for piping output to logger. The SIGHUP breaks the 'connection' between these two, thus they will both exit. Seems hacky but I'm out of ideas.
Note that $PPID is not standardly available in all shells.

run inotifywait on background

I have this code copied from linuxaria.com as example and work just fine on my case the problem is when I exit from terminal inotifywait stop. I want run on back ground even after exit the terminal. how I can do that?
#!/bin/sh
# CONFIGURATION
DIR="/tmp"
EVENTS="create"
FIFO="/tmp/inotify2.fifo"
on_event() {
local date=$1
local time=$2
local file=$3
sleep 5
echo "$date $time Fichier créé: $file"
}
# MAIN
if [ ! -e "$FIFO" ]
then
mkfifo "$FIFO"
fi
inotifywait -m -e "$EVENTS" --timefmt '%Y-%m-%d %H:%M:%S' --format '%T %f' "$DIR" > "$FIFO" &
INOTIFY_PID=$!
while read date time file
do
on_event $date $time $file &
done < "$FIFO"
You can run the script with screen or nohup but I'm not sure how that would help since the script does not appear to log its output to any file.
nohup bash script.sh </dev/null >/dev/null 2>&1 &
Or
screen -dm bash script.sh </dev/null >/dev/null 2>&1 &
Disown could also apply:
bash script.sh </dev/null >/dev/null 2>&1 & disown
You should just test which one would not allow the command to suspend or hang up when the terminal exits.
If you want to log the output to a file, you can try these versions:
nohup bash script.sh </dev/null >/path/to/logfile 2>&1 &
screen -dm bash script.sh </dev/null >/path/to/logfile 2>&1 &
bash script.sh </dev/null >/path/to/logfile 2>&1 & disown
I made a 'service' out of it. So I could stop/start it like a normal service and also it would start after a reboot:
This was made on a Centos distro So I'm not if it works on others right away.
Create a file with execute right on in the service directory
/etc/init.d/servicename
#!/bin/bash
# chkconfig: 2345 90 60
case "$1" in
start)
nohup SCRIPT.SH > /dev/null 2>&1 &
echo $!>/var/run/SCRIPT.SH.pid
;;
stop)
pkill -P `cat /var/run/SCRIPT.SH.pid`
rm /var/run/SCRIPT.SH.pid
;;
restart)
$0 stop
$0 start
;;
status)
if [ -e /var/run/SCRIPT.SH.pid ]; then
echo SCRIPT.SH is running, pid=`cat /var/run/SCRIPT.SH.pid`
else
echo SCRIPT.SH is not running
exit 1
fi
;;
*)
echo "Usage: $0 {start|stop|status|restart}"
esac
exit 0
Everything in caps you should change to what your script name.
The line # chkconfig: 2345 90 60 makes it possible to start the service when the system is rebooted. this probably doens't work in ubuntu like distro's.
The best way I found is to create a systemd service.
Create systemd file in /lib/systemd/system/checkfile.service:
sudo vim /lib/systemd/system/checkfile.service
And paste this there:
[Unit]
Description = Run inotifywait in backgoround
[Service]
User=ubuntu
Group=ubuntu
ExecStart=/bin/bash /path_to/script.sh
RestartSec=10
[Install]
WantedBy=multi-user.target
and in /path_to/script.sh, you can have this:
inotifywait -m /path-to-dir -e create -e moved_to |
while read dir action file; do
echo "The file '$file' appeared in directory '$dir' via '$action'" >> /dir/event.txt
done
Make sure that your file is executable by the user:
sudo chmod +x /path_to/script.sh
After creating two files, reload systemd manager configuration with:
sudo systemctl daemon-reload
Now you can use start/stop/enable to your script:
sudo systemctl enable checkfile
sudo systemctl start checkfile
Make sure to replace file/directory/user/group values before executing.
replace -m with
-d -o /dev/null
ie:
inotifywait -d -o /dev/null -e "$EVENTS" --timefmt '%Y-%m-%d %H:%M:%S' --format '%T %f' >"$DIR" > "$FIFO" & INOTIFY_PID=$!
You can check the inotifywait help manual at:
https://helpmanual.io/help/inotifywait/
Method that will work even if the file to be watched is not there yet, or gets deleted in between (just watch the whole directory instead of a single file, and then do the action on a particular file):
nohup inotifywait -m -e close_write /var/opt/some_directory/ |
while read -r directory events filename; do
if [ "$filename" = "file_to_be_watched.log" ]; then
# do your stuff here; I'm just printing the events to file
echo "$events" >> /tmp/events.log
fi
done &

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