Cron is a job scheduler that allows users to run commands periodically.
3
votes
1answer
46 views
Is it possible to put arithmetic expressions in a crontab?
I know I can do simple arithmetic in shell scripts, like so:
#!/bin/bash
((sum = 1 + 2))
echo sum
This will output 3 on execution. My question now is, can this kind of expressions be used in ...
-2
votes
1answer
28 views
How to send a message in Minecraft before rebooting the server? [duplicate]
I have a Ubuntu Linux Server 14.04 LTS which is running a Minecraft server.
I want it to reboot every 6 hours. I have that now and after the reboot, it starts the Minecraft server.
Now what I want. I ...
0
votes
1answer
34 views
Autodelete old files
I've many shares on my samba server with recycle bin module activated.
When deleting remote files from Windows I see .Trash directory.
I'd like to automatically remove older files, i.e. 30 days or ...
1
vote
1answer
16 views
Add a custom CRON job from the command line?
Debian seems to have directories for cron jobs such as /etc/cron.daily and /etc/cron.hourly, but is there a way for me to automate editing, removing, and updating cron jobs from an automated script?
...
2
votes
3answers
46 views
Limit a text file to 100MB
I have several log files on my server that I would like to limit to 100MB large. I'm considering creating a cron job that will run once a month and remove the oldest characters (closest to the top) ...
2
votes
0answers
47 views
`crontab -e` sometimes fails with “Creation of temporary crontab file failed”
From time to time crontab -e fails on me on a Ubuntu box. It is the same for all users including the root and crontab -eu <user> under the root. Goes like this on a regular basis, a success here ...
1
vote
1answer
24 views
Insert variable and keep the variable
I'm on VMWare which, no matter what anyone says, responds to most unix commands.
Some things are unique though, for example the fact that almost no files are persistent through reboot. Due to this ...
9
votes
1answer
75 views
Finding which cron jobs are scheduled to run at some future date/time X
Is there a way to "query" a crontab to find which cron jobs run at some arbitrary date/time, or during a certain range of times?
For example, determine which will be run at sometime between 14:00 and ...
2
votes
1answer
17 views
don't log cron events in auth.log
In my /etc/rsyslog.conf, I have following line to log auth facility into /var/log/auth.log:
auth,authpriv.* /var/log/auth.log
but the file is flooded with cron logs, sucgh as these:
...
0
votes
2answers
25 views
Write log for a false statement of an if condition which returns exit 2
I have a script running every 5 mins with two exits in a condition clause.
#!/bin/bash
date=$(date +%Y)
if [ $date -eq '2014' ]
then
echo "Current year is $date"
exit 0
else
echo "Current ...
1
vote
2answers
50 views
Script runs manually but not from cron
As per the monitoring of my mysql replication status. I wrote a simple shell script with the following code
#!/bin/bash
date > /tmp/mysql_repl_status.txt
cd /usr/bin/
"/usr/bin/mysql" "-e" "SHOW ...
2
votes
1answer
12 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 ...
4
votes
2answers
92 views
Execution order with multiple commands
I'm relatively new to Linux and I'm working on a CronTab for scheduled backups.
I figured out how to do multiple sequential jobs with ; and &&, but I'm unsure how the dependency affects the ...
1
vote
1answer
23 views
Crontab does not run?
crontab -e
0 */4 * * * root /usr/bin/rsnapshot hourly
30 3 * * * root /usr/bin/rsnapshot daily
0 3 * * 1 root /usr/bin/rsnapshot weekly
30 2 1 * * root /usr/bin/rsnapshot monthly
tail ...
1
vote
2answers
32 views
Where is the cron information stored on my gentoo system?
I have a Linux gentoo system, which performs a cronjob every day at 3:10 in the morning. However, no file in /etc contains any related information to this particular cronjob, and the result of crontab ...
3
votes
1answer
137 views
Cron job to delete files older than 3 days
I need to remove files older than 3 days with a cron job in 3 different directories. (these 3 directories are children of a parent directory /a/b/c/1 & /a/b/c/2 & /a/b/c/3) Can this be done ...
6
votes
1answer
173 views
Recover cron jobs accidently removed with crontab -r
I entered crontab -r instead of crontab -e and all my cron jobs have been removed.
What is the best way (or is there one) to recover those jobs?
3
votes
2answers
56 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 ...
2
votes
1answer
50 views
How do I set cron to run on background?
I am on ubuntu 12.04 and following this tutorial. I want to setup cron to run in the background but I don't have a chckconfig in sbin so I can't run sudo /sbin/chkconfig crond on
I am fairly new to ...
27
votes
1answer
1k views
Why aren't crontabs stored in user home directories?
I'm curious to know: why are crontabs stored in /var rather than in the user's home directories? It makes it a total pain to isolate these files for upgrades but I suspect that there is a logical ...
-1
votes
1answer
39 views
Cron spamming because of renice [closed]
I have a bash script that I execute using cron.
The script begins like this:
#! /bin/bash
DIR=/home/pi/bin/run
renice 19 -p $$
ionice -c 3 -p $$
:
Now, every time cron runs this script it sends ...
1
vote
1answer
109 views
Shell script and crontab to capture file size, name and date in a CSV file and then send via email?
I have a number of zip files in a certain folder. I want to capture file name and the size of the files in a CSV format in day wise and put it in crontab so I can report on a daily basis, and then ...
1
vote
1answer
30 views
Logrotate behaving unexpectedly
Find below the logrotate configuration that I'm using
/usr/local/nagios/var/nagios.log {
copytruncate
daily
rotate 7
compress
missingok
size 100M
}
And I could notice that ...
2
votes
1answer
30 views
XML command line tool postgres
I have an XML files to read and load into database daily at night (cron)
So i planed to do this in a batch.
Is there any command line tool to :
1. Create a postgres schema using an XSD file?
2. ...
3
votes
1answer
83 views
Automatically detect when a file has reached a size limit
I would like to send an email when a file reach a certain size limit.
The only way I thought of doing this is by doing a cronjob which will check the file size and send the email if the file is ...
0
votes
0answers
64 views
Using gpg-agent to decrypt password in cron job
I have two scripts that both need to decrypt passwords using gpg-agent. Both of them run fine when launched from the terminal. The problem is that when run via cron, they both fail with these ...
0
votes
2answers
142 views
Run a script at startup
I am using Ubuntu 14.04. I wrote a small script named trial. The contents of the script are as follows:
#!/bin/sh
SHELL=/bin/sh
PATH=/bin:/sbin:/usr/bin:/usr/sbin
sh -c firefox
I copied the ...
3
votes
1answer
63 views
Crontab suspicious activity
I tried using crontab -l from my terminal as root, it showed no crontab for root. So I tried crontab -e, it returns the following
no crontab for root - using an empty one
888
and then the ...
1
vote
1answer
54 views
debian7 cron.allow & cron.deny files
Almost 3 weeks that, in my downtime, I try to find out where the files cron.allow & cron.deny are located in debian7 distro. No way, it seems that by default they are not in the system.
'Just' ...
0
votes
0answers
40 views
Fetching all Git repositories in the background
I'm thinking about setting up a cronjob for fetching all my repositories every once in a while, to have the current status ready in case I'm offline. Something like the following (wrapped for better ...
4
votes
1answer
87 views
BASH_ENV and cron jobs
I have several questions related to non-interactive, non-login shells and cron jobs.
Q1. I have read that non-interactive, non-login shells only "load" $BASH_ENV.
What does this exactly mean? Does ...
1
vote
0answers
50 views
Cron job running but not establishing tunnel
I have a script which establishes a reverse tunnel on an endpoint HostB. It looks like this:
cat tun.sh
#!/usr/bin/env bash
# Test code
/usr/bin/ssh -V 1> /home/userA/bin/tun.stdout 2> ...
0
votes
1answer
45 views
How to force crontab to check for changed files
I have a gentoo Linux system in which I am logged in as root. How can I force crontab to read new/changed files in /etc/cron.d immedeately, so that even a new cronjob is executed if even only seconds ...
2
votes
2answers
71 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 ...
1
vote
3answers
495 views
How do I find out why cron is not running my jobs?
I'm using Ubuntu 14.04, and the cron daemon is running:
# ps ax | grep cron
822 ? Ss 0:00 cron
but it is not executing any jobs. I was previously getting entries in /var/log/syslog such ...
1
vote
2answers
42 views
cronjob time 13 * * * *
It surely going to sound like a silly question but
i wanted to have a confirm about that crontab time
13 * * * *
does it really mean to launch at the 13th minute of every hr of every day of every ...
1
vote
0answers
54 views
Incrontab does not execute command
When I use incrontab out of the box, I mean no changes,
I get no result, as if the command was not executed.
my incron line is :
/crrae IN_CREATE,IN_CLOSE_WRITE,IN_MOVED_TO /usr/bin/unix2dos $#
the ...
2
votes
1answer
28 views
Conflict between cron.deny and allow who wins?
which one wins in conflict deny or allow? Is the behavior the same for hosts.allow and all the other similar files?
3
votes
2answers
65 views
System Crontab or Root Crontab
System crontab:
/etc/crontab
Root crontab:
sudo crontab -u root -e
Which way is preferred? As they all run tasks within administration privilege.
3
votes
2answers
253 views
Automating backups run from a bash script in Linux the right way
I have a bash script I wrote to backup a Moodle installation. It works fine, I've tested the backups, but there's a problem with it; when I do the backups, since I have to use sudo to type the ...
2
votes
1answer
98 views
Executing PHP with CronJobs in CentOS 6.4 not working?
So I've spent around 2-3 hours now and some times researching, I found several of the same responses online but none seem to work!
I'm trying to execute a PHP script every minute (as a test), but it ...
-1
votes
1answer
98 views
How to set up a cron entry that runs at 00 and 30 after the hour?
I have a cron entry that runs every 30 minutes -
*/30 * * * * /home/myuser/myscripts.sh
How to set this up such that it runs exactly at 30 minute intervals but also exactly at (for example)
3:00 ...
16
votes
4answers
759 views
Path independent shebangs
I have a script that I want to be able to run in two machines. These two machines get copies of the script from the same git repository. The script needs to run with the right interpreter (e.g. zsh).
...
1
vote
2answers
62 views
Running a cron job from another shell
I would like cron to run a script from a specific shell (Zsh). I thought the following would work:
00 02 * * * exec zsh; /path/to/script.sh
but apparently it doesn't, why?
This also made me ...
1
vote
0answers
27 views
How to block the user for a certain amount of time
Suppose, I am working in X environment, and I want to have an obligatory periodic rest. Is it possible to setup a root cron job, that will block my user for 5 minutes every 45 minutes?
I am using ...
3
votes
5answers
502 views
bash restart mysql when it gone run well in SSH part, but not in cronjob
My system is centos 6.5,
I write a simple bash shell to check if mysql is crashed, restart service again. I put it in /home/myspace/mysql.sh chown root:root /home/myspace/mysql.sh then run every ...
0
votes
0answers
74 views
why daily cron isn't running on CentOS 6?
I have a daily cronjob set up on CentOS 6 OS which should look after the log rotation job. The file is /etc/cron.daily/logrotate and it's contents are
#!/bin/sh
/usr/sbin/logrotate ...
1
vote
1answer
72 views
Why CRONTAB tasks are lost when quit Putty session? [closed]
I logged to remote computer, running under Solaris, using Putty and added some jobs to be run by cron. When I quit console and logged once again all jobs was lost.
crontab -l myuser
How do I ...
2
votes
1answer
183 views
Why do deleted files continually reappear?
I've been having a strange issue recently, where I would delete files from a location (i.e. Desktop), and then empty the Trash. However, a day or so later (I'm not sure exactly what triggers it), the ...
1
vote
1answer
93 views
automate updates with a bash script and cron
I'm trying to automatize the updates of debian system, without making upgrades. Then i'll send an e-mail to me, everytime there is an upgrade available.
I've tryied to do it with cron-apt, but i ...
