Cron is a job scheduler that allows users to run commands periodically.

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Are changes in crontab applied when the file is saved, or when the editor is closed?

When I do crontab -e, are the changes applied immediately when I save the file, or do I have to exit vim for it to be applied?
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Calling scripts from inside other scripts

I have a script which I call every 10 minutes with a cronjob: */10 * * * * ~/mydirectory/myscript.sh Now, inside ~/mydirectory there is also another script, let's say myotherscript.sh which I'd ...
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Cron job to check if PHP script is running, if not then run

I am wondering if someone might point me in the right direction. I've got little experience working with the Linux command line and recently due to various factors in work I've been required to gain ...
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How come crontab -e is different from less /etc/crontab?

Im pretty new to unix and crons, I was currently about to try to add crons to an existing cron file. I read you could do this with crontab -e. The confusing thing to me is just that crontab -e shows ...
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370 views

How can I manage my crontab effectively to avoid issue by multiple updates by multiple users?

I have a crontab that includes many users updating it. The problem is that because of this, it is not easy to know who did what modification of a cronjob. I was thinking to create a script to do a ...
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900 views

cron from multiple files

How do I make cron daemon check cron entries from more than one files. In my project I need to frequently update cron file, so instead of manipulating the existing file I was planning to write my ...
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Shall I save my crontab file in /tmp?

I ssh to a server, and want to add some daily jobs (specifially to renew Kerberos tickets even when I log out and I still want my programs in screen or tmux continue to run) to cron. So I run crontab ...
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Cron not running my script

I'm not sure why but my app never executes when I reboot my machine. In crontab > crontab -e I see @reboot /root/myscriptname.sh The file is #!/bin/bash nohup mono-sgen /root/myapp.exe ...
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Installing crontab using bash script

I have created a script to install two scripts on to the crontab. #!/bin/bash sudo crontab -l > mycron #echo new cron into cron file echo "*/05 * * * * bash ...
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719 views

Script to check a folder, print the files then delete those files

I am looking for some guidance on creating a script that will check a specific folder, print all documents (if any) and then delete those documents. I would also like to run this script as a cron job. ...
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Crontab entry with hour range going over midnight

Is this valid crontab time specification, doing what is expected: 0 22-4 * * * Or is it necessary to do something like 0 22,23,0,1,2,3,4 * * *
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Python script to shutdown system doesn't work in cron

A python script to shutdown system works fine from the terminal but doesn't work when included in crontab. The script is called by cron but ends with an error 'shutdown command not found'or 'init 0 ...
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crontab “0/15” minutes + “11-15” hour field: when does that end?

Given a crontab expression like "0 0/15 11-15 ? * MON-FRI", how is that parsed? I am correct in assuming the 11-15 does not mean "between 11 and 15" but "when the hour is 11-15, inclusive" - i.e. ...
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Why is cron ignoring a / (forward slash) interval?

I want to set up a job to run every 15 minutes, starting at the 5th minute. This is my crontab line: 5/15 * * * * /root/job.sh >> /root/job.log But it only runs once an hour, on the fifth ...
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84 views

Time remaining for the next run

I need to calculate the time remaining for the next run of a specific job in my Cron Schedule, I've a Cron with jobs having frequencies of per hour, thrice a day etc, no jobs running on specific ...
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48 views

How to suspend a process for a certain period of time?

I have several running processes which is started by a shell, but I don't want them to run during 08:00am - 20:00pm for each day because they are really bandwidth-consuming, so , I have to suspend ...
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3k views

How to run a cron job to execute every minute?

I am trying to create a directory having timestamp in its in name in /home directory. I have created following cron job as root user. But it's not running. What's wrong I am doing? Following is my ...
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Incorrect cron for midnight?

I checked the crontab set by the hosting company and they have this: 0 * * * * /usr/bin/php /www/sites/[domain.com]/files/html/shell/indexer.php reindexall Does this cron run constantly or once at ...
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265 views

where does Cron look for the default mail binary?

I have setup Cron Jobs to run inside a Chroot Environment, depending on the User/Group; I have noticed that these cron jobs, running inside the chroot environment, fail to send any mail. Log files ...
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cronjob for automatic DB backup to date prefixed file

I am using the latest Linux Mint. I was wondering if it's possible to create a special cronjob for a database backup. In my /etc/cronjob file I have the following code: # Minute Hour Day of ...
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cron midnight 00 24 or 00 00? [closed]

My current crontab looks like this: 00 00 * * 1-5 "/home/user/script.sh" But it seems like it is not being triggered, all others are triggering fine except the one running at midnight. What is the ...
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72 views

Is it possible to use the at command to schedule a job to run at a given timestamp?

I want to schedule a file to run using the at command, as described in this tutorial. I see that the at command supports the posix format -- but I don't see any mention of timestamps. Surely it is ...
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How can a normal user trigger a root cron task to execute immediately, without delay?

I have a root cron task that runs every day. But I want to allow normal users to request that it run immediately, if they so wish. It is a harmless process and it can run as often as needed and these ...
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788 views

How to restore default crontab file

I have recently lost my cronjobs. now when i do crontab -e i am presented with an empty file. i would like to get the default file back with the nifty comments and explanaitions at the top!
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346 views

Cronjob output to log

I'm using a script for testing broadband speed and I would like to set up a cronjob for testing every n minutes and output to a file. The command to launch it from a shell console and append to ...
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Need help with a script to test for memory usage [closed]

I'm trying to put up a temporary band-aid while I work out a solution for a app's memory leak. What I wrote was a small bash script that I put in the root on the server. This is what the script is ...
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Stop cron sending mail for backup script?

I have set up a backup script to back up world data on my Minecraft server hourly using cron, but because the worlds being constantly edited by players, tar was telling me that files changed while ...
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set up local mail delivery to user from cron script

A line in my cron.daily script not work as expected. I haven't any special smtp mail server in system, this line rsync -avun --inplace /oneuser/file.xls /otheruser/file.xls| mail -s "$0 $?" ...
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Users home path in a bash script

I'm writing a bash-script that will be run as a cron job everyday. Very basic, I was wanting to change the wallpaper daily. I have mint-14 with mate. The thing I'm getting caught up on right now ...
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Watchdog script to keep an application running

I currently use an application called MxEasy on my linux servers to display video from a couple of IP cameras. The software is rather buggy and crashes occasionally. I've wrote a script that checks to ...
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481 views

How to use crontab (Gentoo)?

First I installed and ran crontab: emerge cron crontab -e In another console, I ran man cron, but this has no examples of how to use crontab. Where can I get examples, and why are there none in the ...
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Periodically download attachments from mail box

Is there a preferably CLI based program I can use to regularly (through cron for example) use to check a mailbox, and download the attachments into a folder? I have a mailbox called ...
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Custom directory for cron commands

I'm using vixie cron on Debian/Ubuntu. How to set a custom directory to be read by cron? I want to lead crontab to run commands found in a series of files, e.g. /home/cron/*.cron or perfectly ...
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740 views

Is there anything in unix crontab to determine this should be executed in PST/CST standard time?

There is this thing in QuartzScheduler where we can say execute this in CST/BST/ or whatever timezone. This is also good when you want to execute some jobs in certain timezones and certain jobs in ...
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List currently running cron tab and stop it

I created a cronjob, it runs for a very long time but now don't know how to stop it. Please help.
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789 views

Is there any handy command line tool to manage Cron jobs?

Would someone suggest any handy command line (NOT web) tool or script which adds, enables and disables Cron jobs? I am looking, for example, for the following (or similar) behavior: sh manageCron.sh ...
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stop parallel processing for a cron triggered process

I have configured my webservers cron jobs to trigger some php script, every 15min, but sometimes the script takes morethan 15 min to complete execution, by the time another process of the same script ...
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186 views

Stop cron script from destroying my mirrorlist with invalid data

I have to following cron script that runs daily. As you should be able to see from the code, it outputs the results from reflector to /etc/pacman.d/mirrorlist. $ cat /etc/cron.daily/update-mirrorlist ...
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Only allow process to run between hours x and y

I use a mobile data connection service. I only have unrestricted bandwidth between 9am and 4pm. I wonder how I can "silence" applications such as the Dropbox applet outside that schedule. I thought ...
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59 views

Script not run with cron [closed]

i have a python script when i launch my script all it's ok but when i lauchn my scrypt under crontab i have this errors: .. 2015-04-24 14:36:02,163 ERROR Problème dans le module ...
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Emulating /etc/cron.d/ on OSX

On most modern unixes, cron supports individual crontab files in /etc/cron.d, in which each task executes as a specified user. These files automatically update the crontab once edited. They allow ...
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581 views

Send backup by email with crontab

I use this cron job to do a backup of /home/blah/ each day at 01:00 a.m. : 0 1 * * * tar -zcf /home/blah/backup.tgz /home/blah/ In fact I would prefer that an email is sent to me with the .tgz file ...
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471 views

How to execute recurring Bash script at specific times?

How would I set a script to execute on every Tuesday and Thursday at 11:50am? I've been looking at the at command, but I can't conceive how to use it the way I need to from its man page.
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Cron job not behaving as expected

So I have a python script that pulls down git/svn/p4 repositories and does some writing to a database. I'm simply trying to automate the running of this script and based from what I see in syslog it ...
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95 views

Qt program not invoked by cron

I had a simple Qt program, when running, it shows a simple window with a countdown timer. If you might be interested in the code, please see here. I had crontab line * * * * * ...
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361 views

How can I pass a filename containing percent signs (%) as a parameter to a shell script in cron? [duplicate]

We have currently setup a cron job for our new script as below: 46 22 * * * /gzm_common/diagbat9/global/prod/chgstatus.sh /backups/diagbat9/Demantra/output/SK_ITEM_EXTRACT_MFGPRO_$(date +%m%d%y).txt ...
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178 views

How could I signal to a cron job to skip runs?

I have a cron job that runs every X mins and that I would like to have a way to "signal" it not to do anything if needed. Is there a standard way for this? The only idea I had is to check some ...
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562 views

Suddenly lost all cronjobs

All of a sudden my cron jobs don't work any more. When I type crontab -e I am presented an empty file in the editor /tmp/crontab.3fMYGi/crontab And by empty I mean that not even this standard ...
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1answer
548 views

How to respawn vpnc when it stops?

As root, I've setup a crontab rule that launches vpnc everyday early in the morning (before I arrive at my workplace). But it often occurs that the vpn stopped mid day. As a result, I have to sudo ...
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127 views

How to run a script as soon as the week number changes?

I would like to keep my download folder sorted. My goal is to have the files of the current week in the download folder, and the older files in a folder named after week number and year (eg 2013.09, ...