Crontab is a short form of cron table. It is a configuration file that specifies shell commands to run periodically on a given schedule.

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Trigger a command upon every `crontab -e` edit

We are using a shared Linux server account where as everyone comes and edits the crontab. Usually we take a backup like this crontab -l > `date +\%Y-\%m-\%d\_\%H:\%M:\%S.txt` Is there an ...
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197 views

scheduling with cronjob to run the php file for only one time

How do I run the php file only once using the cron jobs. i.e., to schedule task to work on 20/06/2015 10:30:00 I tried something like this : 30 10 20 6 ? 2015 /usr/bin/php /path/to/my/file/...
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From what context is a cron task executed?

I am asking this question after royally destroying a Linux box. Let me give you some background so you know where I am coming from. I currently have (well... did have) a RedHat Linux box running ...
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how to run cron jobs on GMT not local time?

How can I make cron jobs run on GMT, not local time? this is my crontab file: #m h d m wday command TZ=GMT 5 0,6,12,18 * * * ~/Documents/bash/transfer.sh my jobs seem ...
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236 views

Is crontab running old version of file?

This has been driving me crazy: I run a set of Python scripts once per hour on a Raspberry Pi. I updated one of the scripts, but even after a reboot, it still seems to run an old version of the file. ...
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How do I run a `/usr/sbin/` binary in cron?

As root I added used crontab -e to add my script. However the script uses a binary in /usr/sbin/ and I get an error about it not existing when the script runs from cron. How do I fix this?
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1k views

Set default editor for crontab -e invoked with sudo

I'm using Bash on Debian Squeeze. I just read this topic: change default text editor for crontab to vim I have exported both variables VISUAL and EDITOR to vim for normal user and for root. And this ...
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cron expression for every hour starting from specific time

Every one hour (starting from "now") I am able to schedule using this cron expression (expression) using nodejs cron-job. But I need to set cron every one hour starting from a specific time. For ...
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626 views

Cron job for moving directories older than 24 hours

Well, what I want to do is The cron should run every hour or so It should move the directories in a folder /disk1/data/ older than 24 hours to /disk2/data/ The directories moved should contain all ...
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22 views

schedule a crontab to shutdown the machine after a specific process (with PID) has finished

Say I have this process with PID = 1234 currently running. I don't know how long it's gonna take for it to finish. Is it possible to schedule a cron tab to keep checking for the status of the ...
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440 views

Automating an ssh connection with crontab

I've been struggling to crontab automate a git push process with ssh, and it's proving tricky to setup a key with the ssh agent. Starting with a basic script to test the agent: # set paths (all ...
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249 views

automatically start netcat on localhost and remote-host and keep it active

I found this answer by @jeremytrimble on Stack Overflow which explains how you can read a FIFO file over network. I wonder if it’s possible to start these netcat commands automatically, e.g. in a ...
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5k views

Multiple crontabs for one user

is there a way to use multiple crontab files for one user? Thinking something along the lines of crontab file per project instead of crontab per user... Any help is appreciated...
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305 views

Why are some of my cron jobs not sending emails?

To send emails, I use the standard configuration with: MAILTO="example@gmail.com" Here is the content of my crontab: 00 3 * * 2 echo "Internal Backup (mysql) has started!" && tar -zvcf /...
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665 views

cannot rsync via ssh from crontab

I'm having issues transferring files with rsync via ssh. If I just run rsync -avz devel@10.10.10.83:/home/devel/ $/home/user/rsync/servidor it works as expected since the public key is stored in ...
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246 views

Incron Job is not being executed

I am using incron to monitor one of my file in /var/www/html directory. output of incrontab -l /var/www/html/test IN_ACCESS /home/intel/test.sh This job is supposed to create a file in home ...
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76 views

Check for screen using crontab

Currently, I'm using Debian with the following cronjob for screen at reboot: @reboot screen -dmS app1 /home/app1 @reboot screen -dmS app2 /home/app2 The problem is, that sometimes the application ...
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58 views

Is there any limitation on file names under Unix?

We are using crontab to schedule jobs and it was not picking the files for processing that contain [ or ] or ¿. Is there any limitation on file names or do these characters mean something in UNIX? ...
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9k views

How to save Crontab edits?

I ran crontab -e and made some changes, now how do I save it?
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136 views

Not able to open crontab -l

I am running crontab -l to view the crons on a RHEL server(v5.10) and getting the below error: crontab: error while loading shared libraries: libaudit.so.1: cannot open shared object file: No such ...
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235 views

Why isn't crontab working for me? (Ubuntu 11.04)

I can't get the crontab jobs running. I've checked /var/log/syslog and the scheduled jobs aren't there. I've edited the jobs with sudo crontab -e so they are created for root. This is how my jobs ...
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372 views

Why echo $(crontab -l) outputs current working directory listing and only then the content of crontab file itself?

So if cwd is the /tmp now: crontab -l > #min hour day mon dow command > * * * * * /usr/local/bin/growlnotify -t 'helloTitle' -m 'helloMessage' -n 'myApp' -sw but: echo $(crontab -l) > #...
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733 views

Crontab x minutes past every hour on Ubuntu

I haven't been able to find an example of how to run a command in crontab at 5 minutes past every hour. I assumed that this would work 5 */1 * * * But it doesn't run. Can anyone help? Thanks in ...
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93 views

Crontab cannot find program installed in local user's bin dir

I am trying to run a bash script on a dreamhost account that does some backup operations. The program I use to do the backup is installed in the home directory of the web hosting account under ~/usr/...
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944 views

Background Jobs from cron

I am running a cron on every two minutes. From the cron I am running other shell scripts in background with "&". After cron exits spawned shell script process still runs, this is desired behavior. ...
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How can I change the directory a command thinks it is running in?

How can I run a command that is in a different directory so that the command thinks I've ran it in the current directory? If a command is using basename() or argv[0] (or whatever it's called) to get ...
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42 views

How to execute a Linux Cron Job from day x to y on crontab?

I found that I can use an hour range by using a slash, for instance, 4-20 to run from 4AM until 8PM. But what about day range? Can I use something like: * * 5-20 * * CMD
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1k views

Crontab is using some sort of hidden cache?

I used to have a crontab that ran like this * * * * * /usr/bin/php /var/www/vhosts/default/htdocs/agent/time_keeper.php > /dev/null 2>&1 It worked fine. Now I moved that php script to a ...
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56 views

Performance loss when having too many files in /etc/cron.d?

Is there an amount of files in /etc/cron.d that would lead to worse performance? There are currently about 50 jobs in. In the future there can be up to 200 files in. Am I correct to expect the cron ...
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124 views

setting gvim as editor for crontab

I've see many post saying that by setting the following evnironment variable EDITOR=vim or VISUAL=vim will allow to use vim as code editor for crontab. I would likt to try to use gvim instead ...
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398 views

crontab and binaries in /usr/local/bin

I am working in Redhat and have few programs located in folder /usr/local/bin I would like to call from crontab for root user. I thought that by putting binaries in that folder would be sufficient to ...
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119 views

crontab email is not working as expected. First I got the emails at gmail, now I'm not getting them

First I ran a simple test to see if I could get crontab to send me an email. I created the following line: MAILTO = my_email_address@example.com 1 * * * * /bin/echo "foobar" This worked as expected ...
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How can I run a cron job from PM to AM? [duplicate]

I want to execute a script once an hour from 20:00 to 08:00. Would the following work? 0 20-8 * * * location_of_script_to_run I'm currently using the following: 0 20,21,22,23,0,1,2,3,4,5,6,7,8 * * ...
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641 views

How can I set the terminal encoding when running a crontab job?

I have a crontab job which executes a Ruby script on Arch Linux. It works basically, but when I call "googlecl" to post to my blog, it always shows a "safeDecodeError" exception (eg.: googlecl....
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85 views

Execute script when process reaches 6 hours of lifetime

I wonder if it's possible to execute a perl script when a process with a given PID file reaches a total of 6 hours of lifetime? Can this be done through crontab or similar? The perl script I want to ...
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901 views

Crontab Error Emails: Set Sender to Root Using -f

For a crontab entry in this format, */1 * * * * /usr/bin/php /app/<userid>/command --flag='value' I see this message emailed to <userid>@host (and view via mail) at one per minute: ...
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354 views

redirecting output in crontab

I have a shell script to monitor table stats and java apps. It works fine when I run manually. But if I put it in the crontab it will get stuck if I don't redirect it's output with export display ...
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1answer
285 views

Shutting down Linux server on first Wednesday of every month

I have written a crontab entry as: 00 19 1-7 * 3 /sbin/init 0 It should turn my linux server off on the first Wednesday of every month. Unfortunately the server went off on today (Thursday). Can ...
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1answer
180 views

Cronjob immediately shuts down mac after boot

I was messing around with cronjob trying to get it to forcibly shut down at a certain time everyday, but now I can't keep my computer on. It boots, loads whatever needs to load on startup, then ...
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49 views

Using undefined time in a crontab job

What happens if you program a crontab job like this: * * * * * the command Will it be executed every minute, or what?
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148 views

Getting crontab error on Xubuntu

When running the command crontab -e i get the following error: no crontab for 'myusername' - using an empty one 888 Can anyone please help?
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rsync works fine until I put it in crontab (UPDATE: 'date' doesn't work in crontab)

I've got this rsync command that works just fine when I run it from the command line (Ubuntu Server 12.04.1 LTS). I'd like it to run every hour, on the hour, and output the results (along with errors) ...
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4answers
5k views

Is it possible to use variables in crontab -e?

Can I say: MYPATH=/root/scripts MYSCRIPT=doit.sh 0 1 * * * $MYPATH/$MYSCRIPT in crontab -e ? Is it possible to use variables in crontab -e ?
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436 views

Cron unable to run shell script

I have been trying to get a shell script to run for hours using cron to no avail. I am trying to have the following bash script run every minute #!/bin/bash PATH=/usr/local/bin/ices:/usr/local/sbin:/...
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2k views

Can't get a script to run on startup in Debian 7

I want to get this script to run on startup on my Debian Wheezy server: /usr/bin/bitcoind so I go: $ sudo crontab -e @reboot /usr/bin/bitcoind 2>&1 >/tmp/bitcoind.out & Then save ...
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109 views

scheduling a script that accepts one argument in crontab

i am trying to schedule a shell script that runs for every 10 mins, and the script accepts some argument.. i have done it like this 0,10,20,30,40,50 * * * * sh /home/vpnuser/VPN_BL_GUI/VpnJboss/bin/...
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2answers
657 views

Run Crontab anytime after 4pm

I am trying to run a script through crontab in osx 10.8.5 that will run at 4:30. 30 16 * * 1-5 /Library/Frameworks/Python.framework/Versions/2.7/bin/python /Users/lego90511/PycharmProjects/Stock\ ...
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1answer
271 views

Why the command substitution in the crontab job doesn't work?

crontab -l: * * * * * /Users/michel/Desktop/myScript.sh myScript.sh: #!/bin/bash /usr/local/bin/growlnotify -t 'Fact' -m "$(/Users/michel/Desktop/anotherScript.sh data.txt)" -n 'myApp' it doesn'...
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184 views

Automating python script on a mac not running

I have tried to have this question answered twice now(1, 2). While both were informative none of the solutions have worked, and I don't know why. The first solution was to use launchctl the second was ...
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78 views

crontab schedule rule misunderstanding

I've got some strange behavior of one rule working unexpected. */40 * * * * myshellcommand here I though it would run each 40 minutes, e.g. 00.00 00.40 01.20 02.00 etc but instead it runs 00.00 ...