I am able to execute scrip from command line.
I'm executing it like this:
/path/to/script run
But while executing it from cron like below, the page is not comming:
55 11 * * 2-6 /path/to/script.pl run >> /tmp/script.log 2>&1
The line which is getting a webpage uses LWP::Simple:
my $site = get("http://sever.com/page") ;
I'm not modyfing anything. The page is valid and accessible.
I'm getting enpty page only when I execute this script from crontab. I am able to execute itfrom command line!
Crontab is owned by root. And job is executed as root.
Thanks in advance for any clue!
It's difficult to say what might be causing this, but there are differences between your environment, and the environment created by crontab.
You could try running it through a shell with appropriate args to construct your user environment:
55 11 * * 2-6 /bin/tcsh -l /path/to/script.pl run >> /tmp/script.log 2>&1
I'm assuming you are running it by cron with your own user ID of course. If you aren't, then obviously you should try running it manually with the user ID that cron is using to run it.
If it's not a difference in environment variables (e.g. those that specify a proxy to use), I believe you are running afoul of SElinux. Among other things, it prevents background applications (e.g. cron jobs) from accessing the internet unless you explicitly allow them to do so. I don't know how to do so, but you should be able to find out quite easily.
Related
I have a perlscript file was running fine in crontab but suddenly it stopped running without any modification.
cd /home/user/public_html/crons && ./script.pl 2>&1 >/dev/null
The top of the script file is #!/usr/bin/perl -X
The output expect from this script is changes in database
I have another script file with the same modification and still works fine
When I run the file in the browser it works fine and execute all lines without any problem
I tried full path /usr/bin/perl but it didn't work
I tried Perl at the beginning but it didn't work
I run the command from SSH using putty but nothing happened
I checked log file /var/log/cron but no errors at all
I created temporary log file cd /home/user/public_html/crons/script.pl> /tmp/temp.log 2>&1 to see the errors but the log is empty
Here is the solution:-
I found the issue, There is was a stuck process for the same cron file , so i killed this process and its fixed
You can find your file process like this
ps aux | grep 'your cron file here'
This is a really common antipattern people seem to tend toward with cron.
Cron sends you an email with the output of your script, if it generates any output. People often redirect output to /dev/null to prevent cron from sending the email. This is bad because now the output of your script is lost entirely. Even if the script has some built-in logging, it might generate errors before it gets the log file opened and those are lost. It also might crash in a way that doesn't get written to the logging mechanism.
At a bare minimum, you should just remove 2>&1 >/dev/null to start receiving the email. (and also, test your mail setup using a temporary cron job like 1 * * * * echo "Test" )
The next better solution is to change it to >> /var/log/myscript/current.log and then also set up something to rotate the log files (like logrotate) and also make sure to create that directory with permissions that the script user is allowed to write to it. By only redirecting STDOUT of the script, any errors or warnings it writes to STDERR cause you to get an email, and if there are no errors/warnings the output goes to the log file and no email gets sent.
Neither of those changes solve the root problem though, which is that when cron runs your script it does so with a different environment than you have on the command line. What you really want is a way to run the script with a consistent environment, and log it. The "ultimate solution" is to define your task in some kind of service manager, and then use cron to occasionally start it. For instance, you could use systemd and define a service that doesn't restart, then use systemctl start my_custom.service in your cron job. Now you can test independent of cron, and your tests will have the same exact environment, and be logged by the service manager. As extra bonuses, you are protected from accidentally running your script twice at once, and you get a clean way to stop a running cron job without the danger of stale pid files.
I don't particularly advocate systemd myself, but thankfully there are lots of alternatives:
Runit : http://smarden.org/runit/runsvdir.8.html
S6 : https://skarnet.org/software/s6/
Perp : http://b0llix.net/perp/site.cgi?page=perpd.8
(but installing and configuring a service manager is a bigger task than just using systemd if your distro is based on systemd) Each of these allows you to define a service that doesn't restart. Then you use a shell command to issue a "run once" directive to the supervisor, which runs the task as a child. Now you can easily launch the jobs yourself and see all the errors in the log, and then add that command to the crontab and know that it will run identically when cron starts it.
Back to your original problem, once you get some logging you are likely to discover it is a permission problem or a upgraded module in the system perl.
I am new to using cygwin and don't really understand how the scripting of it works. Currently I am running it on Windows 7 and using task scheduler to do this inefficiently.
What I want to do is to run a .bat file already made that runs tests in the cmd line and than take the results of that test and email that people.
Some side notes:
1. It doesn't HAVE to be a batch file, from my reading I think maybe a .sh would be easier to run with bash. Being able to run it on CentOS would be even better, that way others can run if I leave.
2. This needs to run daily. I would like to run the batch file at around 10 am and give it an hour till the emailed results are sent, unless you can trigger the email when the .bat is done.
3. Every time I run this .bat file it saves the results to a .htm file and overwrites it every time the .bat is run.
Thank you
That could be in the crontab for a a centOS server (/etc/crontab)
0 10 * * * user cd /path/ && /bin/bash file.sh >> result_file
Is that what you needed ? Also, you can install Cron as a windows service with cygrunsrv
I'm not sure how to title that more succinctly and still have it be meaningful.
(Note that this works fine when run mid-day, via cron or manually, so I "know" the script itself is sound.)
I have a cron job (ubuntu 13.04.)
It runs as my user (not root.)
The job itself runs at 6:00 in the morning. It's the first 'business level' job that runs all day.
1 6 * * 1-5 /home/me/bin/run_perl_job
run_perl_job is just:
#!/bin/bash
cd /home/me/bin
./script.pl
The script copies a file to "/mnt/shared_drive/outputfile.xls"
The mount point is defined in fstab as:
//fileserver/share /mnt/shared_drive cifs user=domain/me%password,iocharset=utf8,gid=1000,uid=1000,sec=ntlm,file_mode=0777,dir_mode=0777 0 0
Now. Given that:
When I run the script in a normal shell, it works fine.
When I look at the mount point first thing in the morning (via a normal terminal) it shows up (and is writeable) without event.
When I copy the crontab line and set it to run in a couple minutes, to see the symptom, it works fine (creates the file quite happily.)
The ONLY time this fails is if it's running in its normal time slot (6:01). The rest of the script functions ( the file itself has to be pulled down via sftp, etc.) So I know it's not dying.
It's driving me batty because the test cycle is 24 hours.
I just added the following couple lines to the beginning of the 'run_perl_job' script, hoping it exposes something tomorrow:
cd /mnt/shared_drive
ls -lrt >>home/me/bin/process.log
But I'm stumped. "It's almost as though" the mount point had gotten stale overnight and is waiting for some kind of access attempt before remounting. I'd run "mount -a" at the top of the 'run_perl_job' script if I could reasonably do it. But given that it's got to be sudo'ed, that doesn't seem reasonable to me.
Thoughts? I'm running out of ideas and this test cycle is awful.
how about putting a
umount -f -v /mnt/shared_drive
mount -v -a
into a root cron job just before your script runs. That way you don't need to sudo in your script and have the password in plain sight. -v might give you a hint on what is happening to make it stale
I have a perl script (which syncs delicious to wp) which:
runs via the shell but
does not run via cron (and i dont get an error)
The only thing I can think of is that it read the config file wrongly but... it is defined via the full path (i think).
I read my config file as:
my $config = Config::Simple->import_from('/home/12345/data/scripts/delicious/wpds.ini',
\my %config);
(I am hosted on mediatemple)
Does anybody have a clue?
update 1: HERE is the complete code: http://plugins.svn.wordpress.org/wordpress-23-compatible-wordpress-delicious-daily-synchronization-script/trunk/ (but I have added the path as above to the configuration file location as difference)
update 2: crossposted on https://forums.mediatemple.net/viewtopic.php?pid=31563#p31563
update 3: the full path did the trick, solved
The difference between a cron job and a job run from the shell is 'environment'. The primary difference is that your profile and the like are not run for a cron job, so any environment variables you have set in your normal shell environment are not set the same in the cron environment - no extensions to PATH, no environment variables identifying where Delicious and/or WP are hosted, etc.
Suggestion: create a cron job that simply reports the environment to a known file:
env > /home/27632/tmp/env.27632
Then see what is set in your own shell environment in comparison. Chances are, that will reveal the trouble.
Failing that, other environmental differences are that a cron job has no terminal, and has /dev/null for input and output - so interactive stuff does not work well.
it seems the problem is not in running perl, but locating the Config library
you should try:
perl -e "print #INC"
and run a similar perl script in cron, and read the output
it possible that they differ
I suggest looking at my answer to How to simulate the environment cron executes a script with?
This is an similar Jonathan's answer but goes a bit further.
Based on your crontab, and depending on your installation, the problem might be the "perl". As others note the environment, particularly the $PATH variable, is different for cron. perl may not be in the path so you need to put the full path to perl in the cron command.
You can determine the path with the command $ type perl
I run into the same problem ...
Perl script works but not via CRON => error: "perl: command not found"
... after an update from Plesk 12.0 to Plesk 12.5. But the existing answers were not very helpful for me.
It took some time, but than I found this thread in the Odin forum which helps me: https://talk.plesk.com/threads/scheduled-tasks-always-fail.331821/
They suggest the following:
/usr/local/psa/bin/server_pref -u -crontab-secure-shell ""
That deletes in the /var/spool/cron/crontabs files the line:
SHELL="/opt/psa/bin/chrootsh"
After that, my cron jobs run with out any error.
(Ubuntu 14.04 with Plesk 12.5)
If the perl script runs fine manually, but not from crontab, then
there is some environment path needed by the some package that is not
getting through `cron`. Run your command as follows:
suppose your cron entry like:
* 13 * * * /usr/bin/perl /home/username/public_html/cron.pl >/dev/null 2>&1
env - /home/username/public_html/cron.pl
The output will show you the missing package. export that package path in
$PATH variables
I have a perl script (part of the XMLTV family of "grabbers", specifically tv_grab_oztivo).
I can successfully run it like this:
/sw/bin/perl /path/to/tv_grab_oztivo --output /path/to/tv.xml
I use the full paths to everything to eliminate issues with the Working Directory. Permissions shouldn't be a problem.
So, if I run it from the Terminal (Mac OSX) it works just fine.
But when I set it to run via a cron job, nothing appears to happen at all. No output is created etc.
There isn't anything wrong with the crontab as far as I can see, because if I substitute a helloworld.pl for the actual script, it runs just fine at the right time.
So, what can I do to debug? I can see from looking at %ENV in the two cases that the environment is very different, but what other approaches can I take to debugging? How can I see the output of the cron job, which might be some kind of perl "die" message or "not found" message from the shell or whatever?
Or should I be trying to somehow give the cron version of the command the same environment as when it's running as me?
It's often because you don't get the full environment when running under cron. Best bet is to capture the ouput by using the command:
( /sw/bin/perl /path/to/tv_grab_oztivo ... ) >/tmp/qq 2>&1
and then have a look at /tmp/qq.
If it does turn out to be a missing environment, then you may need to put:
. ~/.profile
or something similar, into the execution chain of your cron job, such as:
( . ~/.profile ; /sw/bin/perl /path/to/tv_grab_oztivo ... ) >/tmp/qq 2>&1
If you're looking at %ENV in the two cases, I'd suggest that, as a first step in your perl script, set %ENV to what it is in a cron job, and then trying to run it from the command line. You may need to exec yourself once for this to take full control:
BEGIN {
if (exists $ENV{something_in_your_env_not_in_cron}) {
%ENV = (...);
exec $^X, $0, #ARGV;
}
}
Now try running it, and seeing if there's anything you can do to debug it (including running under perl -d if required). Most likely, you'll find that you end up adding items back into %ENV one at a time until it magically starts working (LD_LIBRARY_PATH is a good one for this, but ORACLE_HOME or DB2HOME for Oracle or DB2 apps might be good choices, too). Then you can either set the variable in your script, or in the crontab.
I'd run a simple shell script by absolute path from the cron command.
Inside that script, I'd ensure that I trapped stdout and stderr to a known (or knowable) file. I'd also ensure that enough of your environment is set. On Unix, you get almost no environment set at all when you run a command via cron - I'm not sure about MacOS X. The standard culprit for problems is PATH. I have a separate .cronfile that sets my working environment enough that I usually don't have problems - that's an analogue of .profile.
On occasion if you can't figure out what's going wrong with your command line, the simplest way to fix it is to turn the whole thing into a shell script. Ideally you shouldn't have to do this, but it can be the fastest way to solve the problem.
File: /files/cron1.sh
#!/bin/sh
/sw/bin/perl /path/to/tv_grab_oztivo --output /path/to/tv.xml
And then in cron:
/files/cron1.sh
This allows you to test the script independent of cron. Remember though that your login shell runs with different environment variables than cron does.
cron usually captures the output of stdout and stderr and e-mailes any output to the crontab owner.
Did you double check your crontab entry to make sure it's valid and will execute at the right time?
Make sure that the script does not need any environment variables set. Otherwise wrap it in another (bash) script, where you can set the environment variables that the other script expects.