Cron not executing the shell script + Linux [duplicate] - linux

I have a script that checks if the PPTP VPN is running, and if not it reconnects the PPTP VPN. When I run the script manually it executes fine, but when I make a cron job, it's not running.
* * * * * /bin/bash /var/scripts/vpn-check.sh
Here is the script:
#!/bin/sh
/bin/ping -c3 192.168.17.27 > /tmp/pingreport
result=`grep "0 received" /tmp/pingreport`
truncresult="`echo "$result" | sed 's/^\(.................................\).*$$'`"
if [[ $truncresult == "3 packets transmitted, 0 received" ]]; then
/usr/sbin/pppd call home
fi

finally i found a solution ... instead of entering the cronjob with
crontab -e
i needed to edit the crontab file directly
nano /etc/crontab
adding e.g. something like
*/5 * * * * root /bin/bash /var/scripts/vpn-check.sh
and its fine now!
Thank you all for your help ... hope my solution will help other people as well.

After a long time getting errors, I just did this:
SHELL=/bin/bash
PATH=/bin:/sbin:/usr/bin:/usr/sbin
* * * * * /bin/bash /home/joaovitordeon/Documentos/test.sh
Where test.sh contains:
#!/bin/bash
/usr/bin/python3 /home/joaovitordeon/Documentos/test.py;

In my case, the issue was that the script wasn't marked as executable. To make sure it is, run the following command:
chmod +x your_script.sh

If you're positive the script runs outside of cron, execute
printf "SHELL=$SHELL\nPATH=$PATH\n* * * * * /bin/bash /var/scripts/vpn-check.sh\n"
Do crontab -e for whichever crontab you're using and replace it with output of the above command. This should mirror most of your environment in case there is some missing path issue or something else. Also check logs for any errors it's getting.
Though it definitly looks like the script has an error or you messed something up when copying it here
sed: -e expression #1, char 44: unterminated `s' command
./bad.sh: 5: ./bad.sh: [[: not found
Simple alternate script
#!/bin/bash
if [[ $(ping -c3 192.168.17.27) == *"0 received"* ]]; then
/usr/sbin/pppd call home
fi

Your script can be corrected and simplified like this:
#!/bin/sh
log=/tmp/vpn-check.log
{ date; ping -c3 192.168.17.27; } > $log
if grep -q '0 received' $log; then
/usr/sbin/pppd call home >>$log 2>&1
fi
Through our discussion in comments we confirmed that the script itself works, but pppd doesn't, when running from cron. This is because something must be different in an interactive shell like your terminal window, and in cron. This kind of problem is very common by the way.
The first thing to do is try to remember what configuration is necessary for pppd. I don't use it so I don't know. Maybe you need to set some environment variables? In which case most probably you set something in a startup file, like .bashrc, which is usually not used in a non-interactive shell, and would explain why pppd doesn't work.
The second thing is to check the logs of pppd. If you cannot find the logs easily, look into its man page, and it's configuration files, and try to find the logs, or how to make it log. Based on the logs, you should be able to find what is missing when running in cron, and resolve your problem.

Was having a similar problem that was resolved when a sh was put before the command in crontab
This did not work :
#reboot ~myhome/mycommand >/tmp/logfile 2>&1
This did :
#reboot sh ~myhome/mycommand >/tmp/logfile 2>&1

my case:
crontab -e
then adding the line:
* * * * * ( cd /directory/of/script/ && /bin/sh /directory/of/script/scriptItself.sh )
in fact, if I added "root" as per the user, it thought "root" was a command, and it didn't work.

As a complement of other's answers, didn't you forget the username in your crontab script ?
Try this :
* * * * * root /bin/bash /var/scripts/vpn-check.sh
EDIT
Here is a patch of your code
#!/bin/sh
/bin/ping -c3 192.168.17.27 > /tmp/pingreport
result=`grep "0 received" /tmp/pingreport`
truncresult=`echo "$result" | /bin/sed 's/^\(.................................\).*$/\1/'`
if [[ $truncresult == "3 packets transmitted, 0 received" ]]; then
/usr/sbin/pppd call home
fi

In my case, it could be solved by using this:
* * * * * root ( cd /directory/of/script/ && /directory/of/script/scriptItself.sh )
I used some ./folder/-references in the script, which didn't work.

The problem statement is script is getting executed when run manually in the shell but when run through cron, it gives "java: command not found" error -
Please try below 2 options and it should fix the issue -
Ensure the script is executable .If it's not, execute below -
chmod a+x your_script_name.sh
The cron job doesn’t run with the same user with which you are executing the script manually - so it doesn't have access to the same $PATH variable as your user which means it can't locate the Java executable to execute the commands in the script. We should first fetch the value of PATH variable as below and then set it(export) in the script -
echo $PATH can be used to fetch the value of PATH variable.
and your script can be modified as below - Please see second line starting with export
#!/bin/sh
export PATH=<provide the value of echo $PATH>
/bin/ping -c3 192.168.17.27 > /tmp/pingreport
result=`grep "0 received" /tmp/pingreport`
truncresult="`echo "$result" | sed 's/^\(.................................\).*$$'`"
if [[ $truncresult == "3 packets transmitted, 0 received" ]]; then
/usr/sbin/pppd call home
fi

First of all, check if cron service is running. You know the first question of the IT helpdesk: "Is the PC plugged in?".

For me, this was happening because the cronjob was executing from /root directory but my shell script (a script to pull the latest code from GitHub and run the tests) were in a different directory. So, I had to edit my script to have a cd to my scripts folder. My debug steps were
Verified that my script run independent of cron job
Checked /var/log/cron to see if the cron jobs are running. Verified that the job is running at the intended time
Added an echo command to the script to log the start and end times to a file. Verified that those were getting logged but not the actual commands
Logged the result of pwd to the same file and saw that the commands were getting executed from /root
Tried adding a cd to my script directory as the first line in the script. When the cron job kicked off this time, the script got executed just like in step 1.

it was timezone in my case. I scheduled cron with my local time but server has different timezone and it does not run at all. so make sure your server has same time by date cmd

first run command env > env.tmp
then run cat env.tmp
copy PATH=.................. Full line and paste into crontab -e, line before your cronjobs.

try this
/home/your site folder name/public_html/gistfile1.sh
set cron path like above

Related

Write from Shellscript to file when running the script from crontab

What I am trying and tried to do:
I've written a Shellscript which should write some logs into a logfile. Something like:
echo "downloaded header" >> log
I also tried with cat instead of echo and I've given full permissions to the log so it should be accessible for anyone. If I start the script from the command line everything works fine and the entries are made as expected.
It didn't matter if I gave the full path to the logfile or not, I tried both.
The Problem:
If I run the script from crontab and yes It has to work with crontab, nothing is written into my log. So the echo "xy" >> log doesn't work, neither does the cat.
Any Ideas? Thanks in advance.
try this solution:
cat cronjob
* * * * * echo "downloaded header" >> /path/to/log
Then:
chmod +x cronjob
chmod +x script.sh
/etc/init.d/crond start #redhat based servers like centos
/etc/init.d/cron start #debian based servers like ubuntu
crontab cronjob
Try redirecting to the log file with full path
echo "downloaded header" >> $HOME/Log_dir/log ## just an example

Using notify-send with cron

I've been trying to use notify-send with cron. I've checked out tons of answers given on stackoverflow and other forums. But I don't see the notify-send popup appearing. I'm currently running Ubuntu 13.10. I've been able to get this to work earlier (about 3 months ago when I had Ubuntu 11.10) but I don't remember how and I don't see what I'm doing wrong here.
My current crontab looks like:
*/1 * * * * export DISPLAY=:0.0 && export XAUTHORITY=/home/harold/.Xauthority && /usr/bin/notify-send "$(date)"
I've tried many solutions given online including using sudo -u harold right before /usr/bin/notify-send .... I've also tried using export DISPLAY=:0 instead of =:0.0. The popup still doesn't appear.
I've also tried to create a script. The cron job to run the script looks like:
*/1 * * * * cd /home/harold/bin && ./notify-send-test.sh
And my script (notify-send-test.sh) looks like:
#!/bin/bash
#export DISPLAY=:0
#export XAUTHORITY=/home/harold/.Xauthority
/usr/bin/notify-send "$(date)"
echo "trying to notify at $(date)" >> /home/harold/bin/cronlog.txt
I've tried using the commented lines and not using them. None of the combinations seem to work. I've also tried using export DISPLAY=0.0.
I do get the expected output in the cronlog.txt file every minute. This means that my script is being executed but the notify-send is not.
I would like to know what I am doing wrong. Happy to provide any more information that may be of use.
Secondary question:
There was also something about cron not being able to use certain environment variables. I don't get what that meant and how it affects the way I use cron. It would be nice if someone could explain this.
To add to Sakthi's answer.
You can get the DBUS_SESSIONBUS_ADDRESS withouth using nautilus (or gnome or whatever) by typing dbus-launch (see this answer)
So to the script would simply be:
#!/bin/bash
export $(dbus-launch)
/usr/bin/notify-send "$(date)"
If that doesn't work, you could try setting it hard-coded to your user ID:
#!/bin/bash
userid=$(id -u)
DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/$userid/bus"
export DBUS_SESSION_BUS_ADDRESS
/usr/bin/notify-send "$(date)"
You can add echo $(env | grep DBUS_SESSION_BUS_ADDRESS) in the script to check what the env variable is when the script is executed.
The DBUS_SESSION_BUS_ADDRESS env variable will not be set in cron daemon. Setting this value will fix your issue. Add the following changes to your .sh file and call it from crontab.
notify-send-test.sh
#!/bin/bash
username=$(/usr/bin/whoami)
pid=$(pgrep -u $username nautilus)
dbus=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$pid/environ | sed 's/DBUS_SESSION_BUS_ADDRESS=//' )
export DBUS_SESSION_BUS_ADDRESS=$dbus
/usr/bin/notify-send "$(date)"
Crontab
*/1 * * * * /home/harold/bin/notify-send-test.sh

Script produces different result when executed by Bash than by cron

Please consider following crontab (root):
SHELL=/bin/bash
...
...
0 */3 * * * /var/maintenance/raid.sh
And the bash script /var/maintenance/raid.sh:
#!/bin/bash
echo -n "Checking /dev/md0... "
if ! [ $(mdadm --detail /dev/md0 | grep -c "active sync") -eq 2 ]; then
mdadm --detail /dev/md0 | mail -s "Raid problem /dev/md0" "my#email.com";
echo "ERROR"
else
echo "ALL OK"
fi;
#-------------------------------------------------------
echo -n "Checking /dev/md1... "
...
And this is what happen when...
...executed from shell prompt (bash):
Mail with mdadm --detail /dev/md0 output is sent to my email (proper behaviour)
...executed by cron:
Blank mail is sent to my email (subject is there, but there is no message)
Why such difference and how to fix it?
As indicated in the comments, do use full paths on crontab scripts, because crontab does have different environment variables than the normal user (root in this case).
In your case, instead of mdadm, /sbin/mdadm makes it.
How to get the full path of a command? Using the command command -v:
$ command -v rm
/bin/rm
cron tasks run in a shell that is started without your login scripts being run, which set up paths, environment variables etc.
When building cron tasks, prefer things like absolute paths and explicit options etc
Before running your script as a cron job, you can test it with no environment variables using env -i
env -i /var/maintenance/raid.sh

Starting pppd from cron doesn't work

I want to start pppd whenever it disconnects. I am trying to setup a shell script to run every 1 minute to see if it's down and reconnect.
I have a bash script called vpn-check.sh:
ping -c3 10.8.3.0 > pingreport
result=`grep "0 received" pingreport`
truncresult="`echo "$result" | sed 's/^\(.................................\).*$/\1/'`"
if [[ $truncresult == "3 packets transmitted, 0 received" ]]; then
pon VPNname
fi
When I run this script from cli directly, it works and starts ppp but when I run the same through cronjob (for root user), it doesn't work.
I tried the below and didn't work
*/1 * * * * bash /root/vpn-check.sh > /root/cronlog.txt 2>&1
I tried the below and didn't work
*/1 * * * * /root/vpn-check.sh > /root/cronlog.txt 2>&1
Finally, I tried:
*/1 * * * * /usr/sbin/pppd call VPNname> /root/cronlog.txt 2>&1
Can't figure out what could be wrong.
I still don't understand why some scripts work and don't work from cron when it is being called as the correct user according to the logs.
The only solution I found is to run:
crontab -e
and add the following lines to the top (even though I am calling the pppd daemon by the full path):
SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
I fixed it. All this while I was running crontab -e
but for the user name to be added, it needs to be added to the system-wide cron file found under /etc/crontab
user that starts the job can only be added in the above mentioned system wide cron file.
You are missing the shebang from your shell script.
vpn-check.sh should look like:
#!/bin/bash
ping -c3 10.8.3.0 > pingreport
result=`grep "0 received" pingreport`
truncresult="`echo "$result" | sed 's/^\(.................................\).*$/\1/'`"
if [[ $truncresult == "3 packets transmitted, 0 received" ]]; then
pon VPNname
fi
See:
http://linuxconfig.org/bash-scripting-tutorial
What does the line "#!/bin/sh" mean in a UNIX shell script?
I was getting the same problem too.I used #dave's answer to figure it out. You just need to add the user name to the crontab, Add the next line to the end of /etc/crontab file:
*/1 * * * * root bash /root/vpn.sh
Replace the shell name of your own.

rdiff-backup bash script and cron trouble

I have this very simple bash script:
#!/opt/bin/bash
/opt/bin/rdiff-backup --force --print-statistics myhost::/var/bkp /volume1/backups/sql 2>&1 > /var/log/rdiff-backup.log;
/opt/bin/rdiff-backup --force --print-statistics myhost::/var/www/vhosts /volume1/backups/vhosts 2>&1 >> /var/log/rdiff-backup.log;
/opt/bin/rdiff-backup --force --print-statistics myhost::/etc /volume1/backups/etc 2>&1 >> /var/log/rdiff-backup.log;
/opt/bin/rdiff-backup --force --print-statistics /volume1/homes /volume1/backups/homes 2>&1 >> /var/log/rdiff-backup.log;
cat /var/log/rdiff-backup.log | /opt/bin/nail -s "rdiff-backup log" me#email.com;
if I run the script from the command line, in this way:
nohup /path/to/my/scipt.sh &
it works fine, appending each rdiff-backup statistic report to the rdiff-backup.log and sending this file to my email address, as expected. But if I put the script in the crontab, the script make only one rdiff-backup job sending statistics via email. I cannot understand because the script doesn't work in the same way...
Any idea?
this is my cronjob entry:
30 19 * * * /opt/bin/bash /volume1/backups/backup.sh
via crontab only the last job is executed correctly, I think because this is the only one local backup. When I execute the script from command line I use the root user, and the public key of the root user is in the /root/./ssh/authorized_keys of the remote machine. The owner of the crontab file is the root user too, I created them through "crontab -e" using the root account.
First of all you need to make sure the script used in cron doesn't output anything, otherwise:
cron will assume there is an error
you will not see the error if any
A solution for this is to use
30 19 * * * /opt/bin/bash /volume1/backups/backup.sh 2>&1 >> /var/log/rdiff-backup-cron.log;
Second of all, it appears you are losing env variables when executing via cron, try adding the env settings to your script
#!/opt/bin/bash
. /root/.profile
/opt/bin/rdiff-backup --force --print-statistics myhost::/var/bkp /volume1/backups/sql 2>&1 > /var/log/rdiff-backup.log
if /root/.profile doesn't, exist try adding . /root/.bashrc or /etc/profile
I hope this helps.

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