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

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1answer
481 views

ls gives me different sort orders during a cron job

I have a cron job that, among other things, does a recursive ls of a directory into a file. This gets compared to another file that I've created that, supposedly, contains an identical listing of the ...
4
votes
1answer
2k views

start-stop-daemon makes cron pidfile with wrong pid

I have an init.d script to start crond which specifies the following for start(): start-stop-daemon -S --quiet --make-pidfile --pidfile /var/run/crond.pid --background --exec /usr/sbin/crond ...
1
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2answers
2k views

Running `screen` through a @reboot cron job

I want to have a script running in screen at startup. This doesn't work: @reboot pi screen -d -m /home/pi/db_update.py however running this manually as user pi works: screen -d -m ...
1
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3answers
58 views

When will this cron run

Cron: * */6 * * * /path/to/command I want this cron to run once in every 6 hour. Whats wrong with the above cron definition, and why?
3
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2answers
676 views

Automatic Update Script using Cron, Exit Codes, and Logging

I'm managing multiple machines running Debian, Raspian, and Mint. On some of the machines I want to have updating and upgrading automatically. I've drafted a script that I want to do this and log if ...
1
vote
1answer
155 views

How to prevent the termination of Anacron jobs after battery mode commences?

I have a backup script which is run daily by Anacron. It can take around 3 hours to complete. I'm happy for Anacron not to commence the script if the laptop is running on batteries, but once started, ...
0
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2answers
111 views

Split logs from cron jobs

I currently have a log file which has no limit and I was hoping to be able to set up a cron job that would start writing to a new file so it doesn't get too big. Would that be possible? So it would ...
3
votes
3answers
435 views

Automating tasks on a website on a headless server

I want to automate a task which can only be done on a website (with prior login) on my debian server. There is no public API available, so I can't use one. Is there a way to do so? I thought about a ...
3
votes
1answer
350 views

Running time command with cron

So I have a crontab that have this line: 30 16 * * * (time sysbench --test=cpu --cpu-max-prime=20000 run) 2>> ~/cpu.out I use this because time output goes by default to stderr and I want to ...
5
votes
3answers
24k views

How to start a cron job without reboot?

I use a cron job to call offlineimap every 2 minutes: */2 * * * * /usr/bin/offlineimap > ~/Maildir/offlineimap.log 2>&1 I needed to kill the cron job to fix a problem. How can I then ...
1
vote
2answers
486 views

how to automatically cleanup failed PHP uploads in /tmp?

How can I automatically cleanup failed uploads? PHP is storing them in /tmp and all file names look like phpAbCDeF (basically php followed by 6 characters). I know that I can use the command: find ...
2
votes
1answer
419 views

bash script - supervisor program

I have to write a shell-script that have to do the following tasks: -in every 5 seconds it saves:     -how many users are using joe and/or vi;     -if ...
2
votes
2answers
834 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 ...
2
votes
3answers
2k views

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 $?" ...
1
vote
1answer
167 views

Why does rsync look for DSA instead of RSA key when run from cron job?

I want to backup files from a server to my local computer using rsync. I can only log-in to the server with an RSA ssh key. I have stored the passphrase to the key in Seahorse Passwords and Keys, ...
2
votes
1answer
631 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. ...
0
votes
2answers
2k views

Cron job not running / not successful?

I have a couple of cron jobs set up to maintain a local copy of a remote database. The first one downloads the latest version of the database from the remote machine, which runs every day and is ...
2
votes
2answers
396 views

Strange crontab-script interaction (bash)

I'm running Ubuntu 12.04 and bash. I've written a pair of shell scripts that allow me to set an alarm which, after ringing, unsets itself. The first, alarmset, allows me to enter a time and modifies ...
2
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0answers
172 views

Use dedicated per-user log file for cron and?

On Ubuntu 12.04 how can I configure cron to log to a particular file when it runs jobs as a particular user? I am interested in redirecting both the messages that go into auth.log and those going into ...
0
votes
2answers
2k views

Ubuntu crontab php not working

Yes, I have read many, many documentations but I can't get it to work. I have a simple single php file which I want to run once or twice in a minute. My php file is called: cronjob_refresh.php and I'm ...
-1
votes
1answer
240 views

Plesk, Centos server error: Cron <root@…> cd /tmp;curl -s -O http://…/r.png;perl r.png;rm -fr r.png [closed]

I had the bright idea of clearing some space on the root partition. I thought I was fairly safe from what I have read by removing some of the locale files for Plesk and some of the backup.tar.gz and ...
2
votes
3answers
1k views

How can I schedule a python program to run from another python program?

I'm running a Python program on my Linux server, and depending on some external data it has to run again at xx minutes or hours from now. So let's say it runs at 6 AM, and then it has to run again at ...
1
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2answers
593 views

No syntax highlighting when editing crontab

I am trying to figure out why I don't have syntax highlighting when editing my crontab. I have both $EDITOR and $VISUAL set to /usr/bin/vim: > echo $EDITOR /usr/bin/vim > echo $VISUAL ...
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2answers
535 views

Is it possible to have a cron job run more frequently than once every minute?

CentOS 6 I have a shell script that performs a task every minute. The task itself only takes a couple seconds to complete and ideally I'd like to have this shell script execute 2-3 times per ...
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2answers
2k views

Xdotool using “DISPLAY=:0” not works in Crontab

I need to run shell script contains Xdotool codes in /home/z/Desktop/tempo/run.sh. I've tried many ways of DISPLAY=:0 but always not works. I've tried each of below codes, and not works: * * * * * ...
10
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2answers
8k views

cron ignores variables defined in “.bashrc” and “.bash_profile”

I have defined "SHELL" variable in /etc/crontab file: [martin@martin ~]$ grep SHELL /etc/crontab SHELL=/usr/local/bin/bash [martin@martin ~]$ file /usr/local/bin/bash /usr/local/bin/bash: ELF 32-bit ...
0
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1answer
291 views

top not working

My below cronjob is not working. What am I doing wrong here?? */5 * * * * /usr/bin/top -n1 | head -10 >>/tmp/load.txt
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2answers
186 views

Running something in a cron environment?

Cron executes whatever program is sent to it in such a fashion that anything written to STDERR causes either the kernel (or cron I'm unsure) to receive SIGPIPE. How does this functionality work? Is ...
2
votes
3answers
1k views

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 * * *
2
votes
1answer
4k views

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 ...
3
votes
4answers
742 views

How to stop monthly cron output email

Server is Debian 6.0. In /etc/aliases I have; root: me@mydomain.com This is so that root emails get sent directly to me. Today, a monthly script I have placed into /etc/cron.monthly has emailed me ...
2
votes
1answer
164 views

Location of crontab job created by non-privileged user

The issue I currently have is someone has created a crontab process to run on a RHEL 5 box, yet has not left me any privileged user information. How can I execute this cron job that was setup to run ...
4
votes
1answer
224 views

Where is the cron timer

Is there any way to access the cron timers and get the seconds left until the next execution of scripts in the crontab or maybe the seconds since the last?
0
votes
1answer
268 views

ipset not executing from crontab

I have this txt files that contains IPs, one per line of file, that I want to block using ipset. I have this bash script that essentially reads from the plain txt file and constructs an array. Then ...
1
vote
3answers
2k views

Why can't cron job find basic Linux commands?

I'm trying to set up a cron job to run a PHP script daily as part of a web-based booking system. It's been running perfectly for several years on a different Apache server using this in the crontab: ...
-1
votes
3answers
3k views

How to run a shell script with export command in crontab

I have a shell script that exports values of variables when executed. The same values will be used in another script. How to run this script(test.sh) in cron. #!/bin/sh export I="10" echo $I I will ...
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0answers
146 views

External HDD read/write permission changing from a cron job

So, I run an overnight python script that runs a backup of our web data in the /var/www directory, then moves the backups to an external HDD in /media. The script in scheduled in the sudo crontab ...
1
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2answers
114 views

Third cron field doesn't seem to work (job runs when I don't want it to)

I scheduled a job like this: * * 6-8 * 1-5 echo "test" >>/tmp/test.log 2>&1 I expect this job to run only on 6th,7th,8th, these 3 days. but today is 18th, it still runs. What ...
1
vote
1answer
101 views

Lock a script starting daemons

I'm run a script with cron: */10 * * * * flock -n /tmp/lock script I have to make sure that only one instance of the script is running at the same time, and for that I'm using flock. The problem is ...
1
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2answers
106 views

Cron creates vim process but does not display vim

Under MacOSX 10.8.2 I am able to run vim as follows in the bash shell: /usr/bin/vim -c "normal G" -c 'startinsert' ~/.journal If I put the exact same command in a script: #! /bin/bash export ...
3
votes
2answers
2k views

How do the internals of the cron daemon work?

I want to know how cron works internally. Does the process keep checking the current time in an infinite while loop (thus continually consuming CPU cycles)? Or does some function generate an interrupt ...
0
votes
3answers
309 views

Lock folder when running cron

I am setting up my first cron on a Ubuntu Desktop system. I was curious to know if there is a way to lock a folder before a cron is ran and how to set it up? I am following this article. I am just ...
15
votes
7answers
631 views

How to Find a Fugitive Crontab

A few years ago I setup a cron job to automatically ping a URL every minute as part of a monitoring system (that's oversimplification, but it'll do for this question). Because I'm a horrible person, I ...
5
votes
2answers
301 views

How can I peek at the output of a running crontab task on OpenBSD?

I have an hourly hour-long crontab task running with some mtr (traceroute) output every 10 minutes (that is going to go for over an hour prior to it being emailed back to me), and I want to see the ...
3
votes
2answers
632 views

Use /etc/aliases for outgoing mail relayed by postfix with local domain

I'm using Ubuntu 12.04 with postfix configured as satellite system that relays outgoing mail to Gmail. For sake of example, my registered domain is example.com I want root cronjobs' error output to be ...
1
vote
1answer
458 views

Cannot edit crontab

I'm running RHEL 5.6. I type $ crontab -e and all I see is Killed I am, however, able to edit a file (let's say I call it crontab.in) and then type $ crontab crontab.in $ crontab -l and see ...
0
votes
1answer
322 views

How can I check if a file is being downloaded?

I have a Raspberry Pi which I want to use to automate downloads to a network drive. I would like to restart the machine on a regular basis using cron (I've heard they're not the most stable of ...
0
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5answers
681 views

cron job schedule

I created a cron job using * */2 * * * schedule. Can anyone tell me what schedule this refers to? I guess it should execute every 2 hours, but it seems to execute every minute.
0
votes
0answers
333 views

CakePHP shell as cron permissions issue

First to say that I know basics of Linux systems. I am familiar with cron jobs. I am using CakePHP shell as cronjob. The script is using model's method to download pages from site user entered. ...
1
vote
1answer
216 views

Crontab with Github

I want to be able to push a repository to Github at midnight, every night. I know that Github isn't a back-up service, and, in no way am I expecting it to be this - I just want the best up-to-date ...