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

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502 views

Regex for crontab validation

I need to check in bash whether an entry into the crontab file is valid. Is there a crontab command switch? I can extract individual lines and try to control individual items through regex. But I ...
3
votes
4answers
276 views

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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2answers
16k views

How to kill a process in shell script which is running through cron?

I have a shell script which runs in cronjob. This shell script has to kill a process which is running and start the new process again. When I run the script manually it works perfectly fine, but when ...
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2answers
2k views

crontab exclude specific date only

How can I write a cron that will exclude a specific date. let say : I need to run a crontab 6pm to 9pm in every 30 min on weekends and want to exclude 10th may 2014 only. Is It possible? How can I ...
3
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1answer
921 views

output of top gets truncated to 80 columns when run by cron

I have got the following logging script: #!/bin/bash top -b -c -n 1 >> /var/log/toplog/top.log And the following record in my crontab: */1 * * * * /home/clime/scripts/toplog.sh The ...
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3answers
2k views

Solaris: how to forward cron e-mails?

If a cron job produces output it is e-mailed to the user's account. I would like to redirect this e-mail to another e-mail account. Preferably on a user-by-user basis. I've looked into some options ...
3
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1answer
399 views

Cron job results are different from executing from own shell

I am using Ubuntu 12.0.4 I have a script basically with the following codes: lockfile=/var/tmp/mylock if ( set -o noclobber; echo "$$" > "$lockfile") 2> /dev/null; then exit_normally ...
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2answers
859 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 ...
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2answers
1k views

How do I check active crons?

I'm trying to hunt down a cron job (or the equivalent) which I know is running, but I can't find it in the default cron files for my system (FreeBSD / Linux / BSD). How can I tell which ones are ...
3
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1answer
3k views

Maximum Number of Entries in Crontab

If it exists, what is the maximum number of cron jobs (entries?) that can be added to a server's crontab? How do I tell? I'm on RHEL 6. I googled around, but did not see a conclusive answer -- some ...
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1answer
798 views

Scheduled task on reboot

How can I schedule a task to run on next reboot? I understand that we have tools like cron and at to help with scheduling. But they seem to allow scheduling at a specific time and not on specific ...
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2answers
23 views

Control character handling in cron/mailx

I have a cron job which runs a long script producing lots of output. Some of the output is lines delimited by single carriage returns; when run from the command line, these make the successive lines ...
3
votes
1answer
101 views

What could be happening between pidof and kill to cause “no such process”?

I've inherited quite a bit of code and am looking at a cron job that restarts a service once an hour, no other scripts touch this process and this code is ran. #The name of the process has been ...
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2answers
99 views

Find and rm command not obeying exclude list occassionally

I am running a find and rm -rf directory list modified earlier than 7 days with an exclusion list of directories which should not be deleted at any case. This is the script excerpt find ...
3
votes
1answer
55 views

fault-tolerant crond replacement

I'm looking for a replacement to crond, or possibly an extension of it. The feature that I definitely would want to have is fault-tolerance. E.g. if a job failed to run due to the computer not being ...
3
votes
1answer
274 views

What's the easiest way to set up a 2-hour alarm?

I want my computer to play some given .mp3 every 2 hours. I want it to run at startup, and be modifiable with a given .conf file. The choice of .mp3 will also be in the .conf file. The reason is, I ...
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votes
1answer
2k views

Daily logRotate for apache at specific time

How can I execute logRotate daily at a specific time (3h30) each day? Specific details on how to do this would be appreciated. I'm on Debian.
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votes
1answer
4k views

Crontab + Ruby on Rails: /usr/bin/env: ruby: No such file or directory

I have a ruby on rails app and I need to schedule a crontab for a rake task. */5 * * * * RAILS_ENV=production /usr/local/bin/rake -f /usr/local/www/mysite-web-production/current/Rakefile ...
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1answer
1k views

How to add crontab in FreeBSD

I am trying to add a job to my crontab in FreeBSD but it is not working : I have used this to add the job: sudo crontab -e -u vaibhav @daily /home/vaibhav/applications/comparison/scrapy but it is ...
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1answer
223 views

Executing 'ssh-add -D' from a cron job doesn't work

I've set up an openSSH server on an ubuntu-server machine, and I configured it to use public/private key (without password). I want to require both password and key check when the client connects to ...
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4answers
5k views

How to display a (zenity/GUI) dialog to the user after a root cron task has completed

I have a simple periodic cron task that must run as root. I want to use Zenity (or similar) to display a GUI informational dialog to user 1000 (or logged in user or all users) when the cron task ...
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2answers
2k views

Bash script doesn't work as cronjob

I'm trying to get this simple bash script to work within a cronjob. It's used to generate static nginx webserver statistic pages using GoAccess. I tried everything I know to resolve this issue, it ...
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1answer
349 views

ipsec auto --status fails in cronjob

I have a server monitoring script which, among other things, checks the state of an IPSec tunnel using ipsec auto --status It works like a charm when run from the console (as root) but as soon as I ...
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3answers
474 views

cron, every minute ram issues

I have a cronjob which runs php on a wordpres cron.php file. Its mainly used to schedule post and i believe it may refresh cache. Anyways... I run the cron job every minute. I checked out the ps ...
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1answer
56 views

Soft raid1 schedule resync

Debian has a cronjob /etc/cron.d/mdadm that starts a raid check (& resync?). It costs a lot of IO and can take up to 96 hours on 3TB disks. At this time the performance of the service will go ...
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1answer
369 views

Cron can't access my home directory when I'm logged out

I have quite a strange problem using cron. I distilled it thus far: I created following simple bash script in /home/user1/cron_dir/cron.sh: #!/bin/bash echo "Success" As user1 I created following ...
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2answers
132 views

How to run a command as if it is called from cron

I write a script and set it as a cron job. But due to a difference of environment variables it doesn't work as it should be. In that case I change a little bit with crontab -e and set a cron job time ...
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1answer
2k views

Crontab change MAILTO for only one specific job in Root's crontab

Can I do the following to change where mail goes for one specific crontab job in root's crontab (don't sent to root for Do Something job, just send to porklover): # Make a hambone appear * * * * * ...
3
votes
1answer
3k views

Is there a update manager whitout gnome dependencies for xfce?

I'm looking a update manager for Debian Xfce. I installed xfce on a computer which will be use by laypersons. Therefore, I want another way (graphical) to launch apt-get update && apt-get ...
3
votes
1answer
2k views

Why does sftp hide the log from stdout?

I have a script a.sh, which has an sftp command: echo "Starting to sftp..." sftp xxx@xxx.xxx.xxx.xx << END_SCRIPT ls mput *.csv.gz bye END_SCRIPT echo "Sftp successfully." If I run it ...
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88 views

How do I schedule a cron task to run

I'm looking to crontab a script every hour starting Friday at 5pm... ending Monday at 5am. This script checks if it's completed this week and if it's currently running. If no/no, start task. Off the ...
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3answers
357 views

Detecting cron tasks run by another user

I am currently working through the Nebula challenges on exploit-exercises.com, and one of the challenges relies on a script being run by cron. This is run by another user (flag03) and the user I am ...
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2answers
846 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 ...
3
votes
1answer
585 views

How do I push a Mercurial repository to BitBucket over ssh? [closed]

I created a public key for ssh and registered that key with BitBucket. I then attempted to push: $ hg push ssh://jhayward@bitbucket.org/johncharrell/[project name] pushing to ...
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3answers
5k views

/etc/crontab what does “test -x” stand for

In my /etc/crontab file I have: # m h dom mon dow user command 17 * * * * root cd / && run-parts --report /etc/cron.hourly 25 6 * * * root test -x /usr/sbin/anacron || ( cd / ...
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5answers
181 views

crontab -e not working

I'm running these commands on crontab and it seems that the script are not running every 5 minutes 5 * * * /etc/my_scripts/telnet.sh | telnet >> /tmp/top_Jay.txt 5 * * * ...
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3answers
270 views

Crontab syntax: using '*' for minutes value

What happens if I use '*' for the minutes value? Is the command going to be run every minute? For example: * 4 * * 0 <command>
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2answers
552 views

Is it possible to schedule a cron job to run fortnightly?

Is there a way to schedule a cron job to run every fortnight? (One way I can think of, within crontab, would be to add two entries for "date-of-month"...)
2
votes
1answer
244 views

Cron job not running after giving command in crontab

I am trying to run a cron job in Linux with following command: crontab -e typing the following details and saving it MAILTO="mail@domain.com" 00 01 * * * /usr/local/bin/php /var/www/html/cron.php ...
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votes
3answers
476 views

Weekly cron job to save list of installed packages

I am having trouble figuring out how to set up my first cron job. I simply want to run this command once every week: dpkg -l > ~/Dropbox/installed_packages My /etc/crontab file contains the line ...
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votes
2answers
178 views

Cron only occasionally sends e-mail on output and errors

On Debian 8.1, I'm using a Bash feature to detect whether the stackoverflow.com website is reachable: (echo >/dev/tcp/stackoverflow.com/80) &>/dev/null || echo "stackoverflow unreachable" This is ...
2
votes
1answer
285 views

Task not run by crontab

crontab strangely does not execute my script, although the script is running just fine from the shell terminal. I already made sure that scripts are separated from each other by a new line space. ...
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2answers
595 views

Can I configure error notifications on a specific cronjob entry to go to a different email address?

I have multiple cron job entries configured under a single account: 0 0 * * * /foo/foo.sh 0 2 * * * /foo/foo2.sh 0 4 * * * /foo/foo3.sh Right now, if any of these encounter an error, an email is ...
2
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2answers
7k views

how to set crontab PATH variable

I had a problem running a script from crontab. After some research I understood the problem was because PATH parameter doesn't include /sbin. I looked what it does include in /etc/crontab: ...
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2answers
3k views

Cron to delete particular file(s) from a specific directory

I am new to shell scripting. I am trying to write a cron for unix shell that will delete some files, say after 2 weeks or after 1 month from a specific directory. /somedir1/somedir2/ if(somedir2) ...
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2answers
846 views

Is crontab related to server performance?

I am using Solaris 10, and I am adding many cronjobs to my server's crontab. Currently I have 30 cronjobs in my crontab. one cronjob takes 8 hours to complete ,one other cron job takes 5 hours to ...
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1answer
1k views

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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3answers
138 views

Read each directory and perform actions in Bash script

I have this directory structure at /var/sync: # tree -d /var/sync/ /var/sync/ ├── sync_bi │   ├── replicator => Replicator.php │ sync.php ├── sync_pfizer │   ├── replicator => Replicator.php ...
2
votes
4answers
795 views

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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votes
4answers
2k views

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 ...