I have a crontab like this. the python script will send a message to my phone.
when I execute '/usr/local/bin/python /home/work/alibaba-rocketmq/monitor/monitor.py ' on the command line,I can get the message. but in the crontab . It doesnot work.
why. Thanks for your help
* * * * * /usr/local/bin/python /home/work/alibaba-rocketmq/monitor/monitor.py
You could use another approach and:
Put your script in a file foo.py starting with
#!/usr/local/bin/python
Make sure you give execute permission to that script:
chmod a+x /home/work/alibaba-rocketmq/monitor/monitor.py
use only /home/work/alibaba-rocketmq/monitor/monitor.py in your crontab file.
Related
I want to use cron for execute a script periodically. I want to try a simple script first but it does not work.
This is my script (scritp.sh) which permission are 700:
#!/bin/sh
clear
echo "Hello!"
mkdir Hello
And this is the crontab file when I edit it with the command crontab -e:
SHELL=/bin/sh
* * * * * /home/padro/Documents/script.sh
EDIT:
I have that script on /home/padro/Documents folder. What I do after it is execute the command crontab -e for modify the cron file. In this file I put the shell that I want SHELL=/bin/sh and also the cron schedule expression * * * * * /home/padro/Documents/script.sh. This schedule teorically run the script every minute. Finally I save the file and when a minute passes I can't see the echo of the script on the terminal.
EDIT2:
I have added mkdir hello, because I don't know if the echo of the script is shown on the terminal. But the hello directory is never created.
Any output generated by a program called from cron will by default be emailed to the user owning the crontab (assuming local delivery of mail messages is possible). So I'd suggest that you look in your inbox on the local machine.
To save the output into a file, use a redirection in the crontab, or arrange for the script to write its output to a file.
Jobs started by cron does not run with a terminal, so you should not expect to see your terminal being cleared every minute by running this script through cron.
The Hello folder should have been created in the working directory used by the script (possibly your home directory). To make absolutely sure you know where the script's working directory is, use cd in the script to move to the correct location.
I do not have enough reputation to add comment.
My humble comment would be.
Is the cron file you mentioned via root?
cos chmod 700 a file would be only be executed by owner.
If you are using redhat linux, the user account you use on the first log in is user rights NOT root.
Reference link to a cheat sheet.
su - root
system will prompt root password
crontab -e
* * * * * /home/padro/Documents/script.sh
You can even run a test script, which I did encounter the similar situation as you when I first learnt scripting into your crontab-
* * * * * date > export/home/padro/Documents/testing.txt
If you could, restart the server.
Check if your directory is correct using the command
pwd in linux/unix.
I hope my comment based on my recent learning have helped you.
Edit 1: Remove clear in your script. Thanks...
Edit 2: I believe your Hello folder is created at the core of the root folder try looking for it... or the home directory of the user...
I'm having issues getting my crontab to run I have the following line added to my crontab -e but it won't start. The command runs fine if I run it manually.
0 */3 * * * cd /home/sam/p/ && /usr/bin/python3.5 start.py
Not getting any error messages and can't see the process when I run top or grep for it.
Usually this happens because the cron environment is different from your own. Make sure your start.py script uses full paths to any referenced files or external scripts. Make sure that your start.py script does not rely on environment variables that you have in your shell but it may not. Try piping the cron output to a mail command so you can see what it is doing, like so:
0 */3 * * * cd /home/sam/p/ && /usr/bin/python3.5 start.py | mail -s "cron output" myself#example.com
An easier way to troubleshoot this is to write a wrapper shell script and send the output to a log file.
Create file python_start_cron.sh with contents
#!/bin/bash
cd /home/sam/p/ && /usr/bin/python3.5 start.py
Set the execute bit on this script script and make sure the script works manually
Modify the cronjob as shown below
0 */3 * * * python_start_cron.sh >/tmp/python_start_cron.log 2>&1
After cron executes, check the contents of the log file to ascertain the cause of the problem.
I have the following CRON configuration:
crontab -l
* * * * * curl http://x.com/script.php
But it just doesn't work. The command "curl http://x.com/script.php" triggered manually works
all fine so it's obviously something wrong with CRON. What could go wrong?
From the top of my head, 'curl' is not in the PATH, when cron is trying to execute it. Type its absolute path, or use the PATH variable in the crontab. If that doesn't help, I would check if /usr/sbin/cron is running. If it is, also check permissions of /var/cron/tabs/ and its contents, and check the log file /var/log/cron for any suscpicious errors.
I have added a script in crontab for every 30 minutes. The line goes as follows:
*/30 * * * * root perl /root/perl.pl
The above script has a execution of system command 'top' and it gets printed in a log file.
If I run it manually it runs fine. But while running it via crontab, it does not show up the desired results. Please can somebody help me with this. Thank you.
The command in the above perl script is:
$top = `sudo top`;
The error I am getting is:
sudo: sorry, you must have a tty to run sudo
I changed my command from sudo to visudo. But still the problem remains.
You should use the full path in cron (and use which perl to find the full path):
*/30 * * * * root /usr/bin/perl /root/perl.pl
OR better yet, make the script executable using chmod +x, and add the interpreter to the beginning of the script #!/usr/bin/perl -w and call it directly from cron
*/30 * * * * root /root/perl.pl
Also if there is a problem in the perl script, you could output the result from cron like this
*/30 * * * * root /root/perl.pl > /tmp/myscript.log
You should look into the requiretty setting with regard to visudo. Look for a line that reads Defaults requiretty. You could try commenting it out, but you will be sacrificing some security. See man sudoers.
You could also try running top in batch mode with one iteration:
$top = `sudo top -bn1`;
Batch mode option is for sending output to other programs.
I'm trying to execute a shell script from cron on Freebsd.
To test whether crontab is working at all, I wrote the line
* * * * * echo "Hello" > /home/myuser/logile
and it work fine.
But when trying to execute any script it doesn't do anything, not even an error. (In the script I tried to run is just the same echo command)
Below is the output of crontab -l:
SHELL=/bin/sh
PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin
HOME=/home/myuser
MAILTO=myuser
* * * * * /home/myuser/shellscript.sh > /home/myuser/logfile
Why is the script not getting executed, although crontab is obviously running?
Permission for all files are set to rwxr-xr-x.
* * * * * /bin/sh /home/myuser/shellscript.sh
or
* * * * * /bin/bash /home/myuser/shellscript.sh
worked for me in Macosx 10.6 as rootuser
Have you checked that the command line has a linefeed/CR at the end of the line? I struggled for hours trying to find a reason for non-executing php script on cron when I simply hadn't pressed enter at the end of the line when I edited the cron jobs with crontab -e :-)
Have you checked /var/log/cron for clues?
Have you tried
* * * * * /bin/sh /home/myuser/shellscript.sh > /home/myuser/logfile
cron sends any errors via email to owner of the crontab file (often "root" so you might check that account's email). To have any errors mailed to "crontabOnFreebsd" put:
MAILTO=crontabOnFreebsd
in your crontab (near the top).
For more info issue this command:
man 5 crontab
If you are getting an error, then your logfile might not capture it, try this:
* * * * * /home/myuser/shellscript.sh > /home/myuser/logfile 2> /home/myuser/errorfile
Its been a while since I did any cron stuff; but things that always used to get me:
Environment variables not been set: generally I found it necessary to set up full paths (even to things like 'cat') to all commands [or at least set ENV variables within the script itself].
Ensure the user who owns the script etc is really the user which is running the script: this might not be the same user when you test from the interactive shell. Same goes for the directories/files that the script might write to.
Also: check the email for the root user - you might find that the errors have been diverted to the inbox, which may help you troubleshoot this further.