I have a pretty simple db back-up script that runs perfectly from shell.
php /home/db_backup/db_backup.php
When I attempt to add a Crontab, I get the vague 'Bad Command errors in crontab, can't install."
I've tried w/ php and full path to php.
which php
returns /usr/bin/php
* 1 * * * php /home/db_backup/db_backup.php
* 1 * * * /usr/bin/php /home/db_backup/db_backup.php
Both return the same error.
Centos 6.6. logged in as root. Editing crontab thusly
crontab -e
Spent too many hours trying to get this working. What am I missing?
I bet your problem is when editing the crontab file not with the commands itself.
Be sure to let a blank line at the end of file.
I mean the cursor must be in an empty line after the last entry.
Related
I have a strange problem of being to able to run a bash script from commandline but not from the crontab entry for root. I am running Ubuntu 12.04.
* * * * 1-5 root /home/xxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/jmeter-cron-randomise.sh >> /home/xxxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/cron.log
If I run the script from the cmd line using bash, it works fine but sh fails with following error:
> jmeter-cron-randomise.sh: 7: jmeter-cron-randomise.sh: arithmetic
> expression: expecting primary: " % 1 "
Having googled the problem, it seems like standard shell doesn't have the same math operators, like % (modulus), as bash. I'm Not sure why the cron job is failing in the script? I am assuming it is because it's not using the bash shell? It's definitely being fired by the cron daemon (can see it in /var/log/syslog). Any help much appreciated.
You likely need to tell cron that the shell to use is the bash shell as it defaults to sh. You can do that for all crontab entries by putting this line in your crontab:
SHELL=/bin/bash
Note that this will cause all scripts in the crontab to be run under bash which may not be what you want. If you want to change the crontab line itself to just run bash, change it to this:
* * * * 1-5 root /bin/bash /home/xxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/jmeter-cron-randomise.sh >> /home/xxxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/cron.log 2>&1
Note that I have also caused stderr to be written to the cron.log file (2>&1) which may not be what you want but is pretty common practice. This may help you further diagnose errors from the script.
In case this helps anyone: for me this appeared to be because I had ended up with "DOS" line endings (CR-LF) instead of "unix" line endings (LF). This can be checked using od or your favourite hex dump tool, e.g.:
od -c <script_file>
... and look for \r\n instead of just \n.
It seems (and this article supports it) that the CR character stops the "shebang" from working because it's interpreted as part of the shell executable's filename.
(The line endings themselves appeared because the file came from a git repository and was transferred via a Windows machine).
I also encountered this problem trying to schedule a database backup as root and it made me pull my hair out! I was working on a CentOS 7 box.
Whenever I would check /var/spool/mail/root I would see a log:
sh: root: command not found, yet the command would run perfectly in the terminal.
This is what worked for me:
I created the crontab entry using crontab -e while logged in as root.
Using the command above as an example:
* * * * 1-5 root /home/xxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/jmeter-cron-randomise.sh >> /home/xxxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/cron.log
I deleted the root user entry like:
* * * * 1-5 /home/xxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/jmeter-cron-randomise.sh >> /home/xxxxxxx/jmeter/VerificationService-0.0.1-SNAPSHOT/cron.log
That solved my problem.
I have a script to backup my database at /home/<user>/bin/dbbackup. The script is executable by all users, and owned by me. The files /etc/cron.allow and /etc/cron.deny do not exist.
In my crontab I have the following lines (including a new blank line after the last line of code):
#reboot /home/<user>/.dropbox-dist/dropboxd
30 2 * * * bash /home/<user>/bin/dbbackup
However, cron is not running my dbbackup script. When I run a manual test of the script it works. When I run this test on the command line: * * * * * /bin/echo "cron works" >> ~/file I get the following error:
No command 'dbbackup' found, did you mean:
Command 'dvbackup' from package 'dvbackup' (universe)
Command 'tdbbackup' from package 'tdb-tools' (main)
dbbackup: command not found
My server is running Ubuntu Trusty. Any help please?
As the comments noted, it appears that amiga_os needed remove the reference to bash in the line.
30 2 * * * bash /home/<user>/bin/dbbackup
Should be.
30 2 * * * /home/<user>/bin/dbbackup
I usually just call scripts from their path and use "#!/bin/bash" (or wherever your bash lives) as the first line of the script. It appears the amiga_os had already done this, which is good. I don't like putting sentences into cron because it makes me nervous.
I think it was a path issue as cron executes as the user but does not read the bash profile and therefore does not work exactly like it would under your shell as it might not have access to your $PATH.
i have this crontab,
* * * * * php /etc/raddb/overloaded.php
but it is not running fine, meaning it doesnt run every minute, but when i manually enter this into the terminal (php /etc/raddb/overloaded.php), the script works
thank you guys
PS: im using centos 32 bit. also im using the "crontab -e" to insert and save crontab, but it looks like that crontab is not running? i typed "crontab -e" and yet (* * * * * php /etc/raddb/overloaded.php) appears. where is the issue here? thanks
Crontab syntax is right. Please check if your cron daemon is running and you can check log, maybe it conatins some usefull info.
I think the most possible problem is that cron has its own environment settings. Try to run php with its full path, e.g.
/sbin/php
or w\e path you have
I maintained a database (MySQL), I would like back up some data to the database using a perl script. To save my trouble, I would like cron to do it for me, I inserted the following using crontab
*/5 * * * * blctrl /home/blctrl/code/perl/tt01.pl
However, cron never does its job, any suggestions to get it done? The Linux installed is Centos 5?
*/5 * * * * blctrl /home/blctrl/code/perl/tt01.pl
That looks like the syntax for /etc/crontab, the system-wide crontab file. The first 5 words indicate when to run the command, the 6th is the account under which to run it, and the rest of the line is the command to execute.
(The clue was that the command is under /home/blctrl, which would be the home directory for the account blctrl.)
The syntax for your own crontab, the one you feed to the crontab command, is different. You don't specify an account name, because it only runs under your own account.
Try this:
*/5 * * * * /home/blctrl/code/perl/tt01.pl
EDIT: Incidentally, the first thing I would have tried when encountering a problem like this would be to replace the command with something simple, perhaps touch /tmp/FOO. That would have told you whether the problem was with your Perl script or with your crontab.
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.