Can't make crontab work - linux

I am new to Linux and Ubuntu and I seldom have to use it. I am trying to make this PHP script to run every minute using cron, but firstly I wanted to make some tests.
I created an empty file at /var/www/html/ called test. I ran on terminal:
sudo crontab -e
And added this line:
0 * * * * rm /var/www/html/test
Then saved it and exited. It said "Installing new Crontab"
Nothing happened. Then I created a file bfile.sh that contained:
#!/bin/sh
rm /var/www/html/test
and added the following to crontab:
0 * * * * bash /var/www/html/bfile.sh
Still nothing happened.
What do I have to do to see anything happening from crontab? By the way I checked and the service is running

0 * * * * basically says "run this at 0th minute of every hour."
If you need cron to run your command every minute do * * * * *.

0 * * * * runs once every 1 hour. If you want to run every minute it should be */1 * * * *
You can also check the /var/log/cron file for any errors

Related

CRON job outputting blank lines

I tried to create a CRON job that runs every minute. As a root user, I ran crontab -e, and in the cronjob, I put in my command * * * * * /usr/bin/php {redacted}/index.php > {redacted}/output.txt
the {redacted} file path has permissions added: chmod ogu+rwx -R so everyone should be able to access it. I even created a new user with no sudo or root privileges, and running /usr/bin/php {redacted}/index.php > {redacted}/output.txt obviously writes the output of {redacted}/index.php to {redacted}/output.txt. However, my cron job ends up overwriting and turning the .txt file to just blank, nothing. I have no idea what is going on since I already made sure there were no permission errors, and cron jobs don't seem to have a visible log or output?
I would love to have any ideas about this. I even tried to add the cron job * * * * * root /usr/bin/php {redacted}/index.php > {redacted}/output.txt, all to the same output.
One more thing... I have tried to set the {redacted} location to /var/www/html, /var/www/{a user with sudo perms}, and {/usr/local/bin} all with the same result.
Update:
I tried something as simple as * * * * * php -v > {redacted}/output.txt and * * * * * /usr/bin/php -v > {redacted}/output.txt still with the same result, so it seems like the error is not with requiring root permissions to run my php program

Run yarn script into crontab

I made a script in TypeScript that download data from some api and store inside a mongo DB.
If i run yarn start from the app folder it works well.
I would like to put this command in a cron job that will be executed every 5 minutes.
I try it with some sintax in crontab but ti doesn't work.
I try to put the call in a run.sh script but it doesn't work too.
*/5 * * * * cd /opt/app-folder/src/ && /home/username/.nvm/versions/node/v16.15.1/bin/ts-node main.ts
*/5 * * * * cd /opt/app-folder && /usr/bin/yarn start > /home/username/app-name-out.txt
*/5 * * * * /home/username/run.sh > /home/username/app-name-out.txt
*/5 * * * * /home/username/.nvm/versions/node/v16.15.1/bin/ts-node /opt/app-folder/src/main.ts > /home/username/app-name-out.txt
*/5 * * * * cd /opt/app-folder/src/ && /home/username/.nvm/versions/node/v16.15.1/bin/ts-node main.ts > /home/username/app-name-out.txt
Can someone help me to execute the main.ts every 5 minutes?
Thanks
I get rid of this problem.
There was 2 problems, the first related to the output redirection.
I fixed by redirect stdout in a file and stderr in another one.
The second was related the the $PATH of crontab: it was /usr/bin:/bin.
To fix it I log into my user where script works and I print my $PATH with echo $PATH.
I copied the value and I set it before the crontab line in crontab file.
This is what it looks like:
# Set the same path of user username to have the correct path in script
PATH=/home/username/.nvm/versions/node/v16.15.1/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/snap/bin
# Execute oracle every 5 minutes
*/5 * * * * /bin/sh /home/username/run.sh >> /home/username/app-name-info.txt 2>> /home/username/app-name-error.txt
Now it works.

Cronjobs do not run

I'm trying to run a cronjob to start and stop a server under a non-sudo user. I've tried asking others and doing what I saw from looking on google before asking here, but I'm still stuck.
Here's what's in my crontab for the server user:
* * * * * /home/server/startup/stop.sh
* * * * * /home/server/startup/start.sh
Here is what is in my stop.sh script:
#! /bin/sh
screen -r server -X quit
Everything runs normally if I run it using sh, and I only encounter a problem when using cron.
From what I see there could be 2 possible problems:
If the lines you are running in crontab are (and only those):
home/server/startup/stop.sh
home/server/startup/start.sh
then you are missing the time part of the line. If you want to run your program only once on boot you can run:
#reboot home/server/startup/start.sh
You are not giving the full path to your program (possibly you are just missing a / in the begging). Try running
* * * * * /home/server/startup/start.sh
or
#reboot /home/server/startup/start.sh
If these don't work I recommend you try the following to troubleshoot the issue:
Run the command using sh in the cron:
* * * * * /bin/sh /home/server/startup/start.sh
Try redirecting the stdout and stderr of your command to a file and see if any errors occur

Running cron for nodejs and deleting files in temp

I'm trying to run nodejs /var/www/html/back/elastic/users.js g command every 10 minutes in cron but I don't seem to be able to
*/10 * * * * /usr/local/bin nodejs /var/www/html/back/elastic/users.js
I've added this to crontab -e but when I check syslog it doesn't show there.
Same for the following command I want to delete files in temp every day, it doesn't work either
30 2 * * * rm -rf /var/www/html/data/users/temp/*
What am I missing? Thanks for any help
Ubuntu Server 15.04
Try:
*/10 * * * * /usr/local/nodejs /var/www/html/back/elastic/users.js
and
30 2 * * * /bin/rm -rf /var/www/html/data/users/temp/*
You should try removing the space from the first crontab
*/10 * * * * /usr/local/bin/nodejs /var/www/html/back/elastic/users.js
the second command looks correct to me, is the path correct? Maybe a permission issue.
It should delete everything under /var/www/html/data/users/temp/ at 2:30am

Crontab - simple echo not running

I've got such situation:
I want to schedule a job with crontab on a linux server. I'm not super-user, so I'm editing (with crontab -l, editor vim) only my crontab file. For testing, I put there:
* * * * * echo asdf
And the job is not running. Is the restart of the server needed? Or maybe some administrator move?
May be it is, cron jobs will run in their own shell. So you can't expect to see asdf on your console.
What you should try is
* * * * * echo asdf > somefile_in_your_home_directory_with_complete_path.log
Next check the file by doing a tail:
tail -f somefile_in_your_home_directory_with_complete_path.log
And if it's not, check if the cron daemon itself is running or is down:
# pgrep crond
OR
# service crond status
If you want to echo something on your shell you could use wall:
* * * * * wall <<< "Hello from cron"
* * * * * echo "Hello from cron" | wall
These two lines basically do the same but the first one might not work on older shell, just choose your favorite.
Anyway, be aware that wall will send your message to every user currently connected.
For me * * * * * /bin/echo text > file is not working...I don't know why, previleges and everything is set.
(This command is running normaly when I execute it as the particular
root user, just to clarify this.)
This can be solved by injecting the path PATH=$PATH:/bin in my example.
Instead * * * * * echo text > file is working fine, probably path issue.
Hope I helped

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