Posted By admin On 23/08/21
  1. Recover photos, WhatsApp, contacts and more from any iTunes or iCloud backup (including iOS 13 iCloud backups!) with iPhone Backup Extractor by CopyTrans.
  2. Reliable backup power is more important than ever. At Kohler, we offer powerful, lasting generators to back your home and business. Find yours today.

A hit that allows the batter to make a complete circuit of the diamond and score a run. Backup power mode, called Backup-Only in the Tesla app, reserves 100% of your Powerwall energy to provide seamless power to your home in the event of an outage.Powerwall will charge from the grid (if you don’t have solar) or from your solar system and only discharge during a grid outage.

ow do I add cron job under Linux or UNIX like operating system?
Cron job are used to schedule commands to be executed periodically. You can setup commands or scripts, which will repeatedly run at a set time. Cron is one of the most useful tool in Linux or UNIX like operating systems. The cron service (daemon) runs in the background and constantly checks the /etc/crontab file, and /etc/cron.*/ directories. It also checks the /var/spool/cron/ directory.

crontab command

Tutorial details
DifficultyIntermediate (rss)
Root privilegesYes
Estimated completion time20m
crontab is the command used to install, deinstall or list the tables (cron configuration file) used to drive the cron(8) daemon in Vixie Cron. Each user can have their own crontab file, and though these are files in /var/spool/cron/crontabs, they are not intended to be edited directly. You need to use crontab command for editing or setting up your own cron jobs.

Types of cron configuration files

There are different types of configuration files:
  1. The UNIX / Linux system crontab : Usually, used by system services and critical jobs that requires root like privileges. The sixth field (see below for field description) is the name of a user for the command to run as. This gives the system crontab the ability to run commands as any user.
  2. The user crontabs: User can install their own cron jobs using the crontab command. The sixth field is the command to run, and all commands run as the user who created the crontab
Note: This faq features cron implementations written by Paul Vixie and included in many Linux distributions and Unix like systems such as in the popular 4th BSD edition. The syntax is compatible with various implementations of crond.

How Do I install or create or edit my own cron jobs?

To edit your crontab file, type the following command at the UNIX / Linux shell prompt:
$ crontab -e

Syntax of crontab (field description)

  • 1: Minute (0-59)
  • 2: Hours (0-23)
  • 3: Day (0-31)
  • 4: Month (0-12 [12 December])
  • 5: Day of the week(0-7 [7 or 0 sunday])
  • /path/to/command - Script or command name to schedule
Easy to remember format:

Example: Run backup cron job script

If you wished to have a script named /root/backup.sh run every day at 3am, your crontab entry would look like as follows. First, install your cronjob by running the following command:
# crontab -e
Append the following entry:
0 3 * * * /root/backup.sh
Save and close the file.

More examples

To run /path/to/command five minutes after midnight, every day, enter:
5 0 * * * /path/to/command
Run /path/to/script.sh at 2:15pm on the first of every month, enter:
15 14 1 * * /path/to/script.sh
Run /scripts/phpscript.php at 10 pm on weekdays, enter:
0 22 * * 1-5 /scripts/phpscript.php
Run /root/scripts/perl/perlscript.pl at 23 minutes after midnight, 2am, 4am .., everyday, enter:
23 0-23/2 * * * /root/scripts/perl/perlscript.pl
Run /path/to/unixcommand at 5 after 4 every Sunday, enter:
5 4 * * sun /path/to/unixcommand

How do I use operators?

An operator allows you to specifying multiple values in a field. There are three operators:
  1. The asterisk (*) : This operator specifies all possible values for a field. For example, an asterisk in the hour time field would be equivalent to every hour or an asterisk in the month field would be equivalent to every month.
  2. The comma (,) : This operator specifies a list of values, for example: '1,5,10,15,20, 25'.
  3. The dash (-) : This operator specifies a range of values, for example: '5-15' days , which is equivalent to typing '5,6,7,8,9,..,13,14,15' using the comma operator.
  4. The separator (/) : This operator specifies a step value, for example: '0-23/' can be used in the hours field to specify command execution every other hour. Steps are also permitted after an asterisk, so if you want to say every two hours, just use */2.

How do I disable email output?

By default the output of a command or a script (if any produced), will be email to your local email account. To stop receiving email output from crontab you need to append >/dev/null 2>&1. For example:
0 3 * * * /root/backup.sh >/dev/null 2>&1
To mail output to particular email account let us say [email protected] you need to define MAILTO variable as follows:
MAILTO='[email protected]'
0 3 * * * /root/backup.sh >/dev/null 2>&1

See 'Disable The Mail Alert By Crontab Command' for more information.

Task: List all your cron jobs

Type the following command:
# crontab -l
# crontab -u username -l

To remove or erase all crontab jobs use the following command:
# Delete the current cron jobs #
crontab -r
## Delete job for specific user. Must be run as root user ##
crontab -r -u username

Use special string to save time

Instead of the first five fields, you can use any one of eight special strings. It will not just save your time but it will improve readability.
Special stringMeaning
@rebootRun once, at startup.
@yearlyRun once a year, '0 0 1 1 *'.
@annually(same as @yearly)
@monthlyRun once a month, '0 0 1 * *'.
@weeklyRun once a week, '0 0 * * 0'.
@dailyRun once a day, '0 0 * * *'.
@midnight(same as @daily)
@hourlyRun once an hour, '0 * * * *'.

Home Backup Power Options


Run ntpdate command every hour:
@hourly /path/to/ntpdate
Make a backup everyday:
@daily /path/to/backup/script.sh

More about /etc/crontab file and /etc/cron.d/* directories

/etc/crontab is system crontabs file. Usually only used by root user or daemons to configure system wide jobs. All individual user must must use crontab command to install and edit their jobs as described above. /var/spool/cron/ or /var/cron/tabs/ is directory for personal user crontab files. It must be backup with users home directory.

Understanding Default /etc/crontab

First, the environment must be defined. If the shell line is omitted, cron will use the default, which is sh. If the PATH variable is omitted, no default will be used and file locations will need to be absolute. If HOME is omitted, cron will use the invoking users home directory.
Additionally, cron reads the files in /etc/cron.d/ directory. Usually system daemon such as sa-update or sysstat places their cronjob here. As a root user or superuser you can use following directories to configure cron jobs. You can directly drop your scripts here. The run-parts command run scripts or programs in a directory via /etc/crontab file:
/etc/cron.d/Put all scripts here and call them from /etc/crontab file.
/etc/cron.daily/Run all scripts once a day
/etc/cron.hourly/Run all scripts once an hour
/etc/cron.monthly/Run all scripts once a month
/etc/cron.weekly/Run all scripts once a week

How do I use above directories to put my own scripts or jobs?

Here is a sample shell script called clean.cache. This script is created to clean up cached files every 10 days. This script is directly created at /etc/cron.daliy/ directory. In other words create a text file called /etc/cron.daily/clean.cache as follows.
Save and close the file. Set the permissions:
# chmod +x /etc/cron.daily/clean.cache

How do I backup installed cron jobs entries?

Simply type the following command to backup your cronjobs to a nas server mounted at /nas01/backup/cron/users.root.bakup directory:
# crontab -l > /nas01/backup/cron/users.root.bakup
# crontab -u userName -l > /nas01/backup/cron/users.userName.bakup

Now that you signed up for a Comodo Cloud (CCloud) account, the next step is to back up your files online. The easy and quick way is to use Comodo Backup. Follow the steps below:

Home Backup Generator Dealers Near Me

  • 1. If you've haven't done so already, download the Comodo BackUp setup file from http://download.comodo.com/cbu/download/setups/CB_setup.exe and install it in your computer. Your computer will restart on completion of installation.
  • 2. Start the application by clicking Start > All Programs > Comodo > Comodo Backup > Comodo Backup. Comodo Backup first time run wizard will start to backup your important files.
  • 3. Click 'Login' from the top-right corner and enter your username (your email address) and password as entered during Sign-Up.
  • 4. Comodo Backup scans your system to discover and categorize the different types of files on your computer. Select the file type(s), so that all the files of relevant types stored in your computer (all the drive partitions of your hard disk drive) will be backed-up.
    • My Pictures - All the pictures, image files, photographs, screen captures etc., stored in image file formats like .jpg. .png, .gif.
    • My Documents - All the notepad files, text files, documents, spreadsheet files, presentation files etc., stored in document file formats like .txt, .rtf, .doc, .xls, .ppt, .odt, .ods, .odp, .wpd.
    • My Music - All the sound, audio and music files stored in audio file formats like .mp3, .wma, .wav, .aac.
    • My Videos - All the video files stored in file formats like .mp4, .wmv, .avi, .flv, .swf.
  • 5. Click 'Online Backup'.
    That's it! Your important files are now backed-up to your online storage space.

You can also schedule for backup of your important files and folders from different locations.

  • 1. Start the application by clicking Start > All Programs > Comodo > Comodo Backup > Comodo Backup.
  • 2. Click 'Backup Now' on the summary screen.
  • 3. Select the files, folders and other important areas that you want to back up from the 'Backup Source' area and click 'Next'.
  • 4. Select 'Online Storage' as the 'Backup Destination'
  • 5. Enter your username (email address) and password then click 'Sign In' (remember to enable 'Sign In Automatically')
  • 6. Click the alarm clock icon to configure a backup schedule.
  • 7. Click 'Next' if you wish to configure advanced backup settings.
  • 8. Click the 'Backup Now' button when you are ready to start copying your files to online storage.

That's it. Comodo Backup will begin copying your files over to your online storage immediately. Future backups will run according to the schedule you specified.
The powerful application Comodo Backup also allows you to backup your files and folders, Windows Registry, Email account settings, IM conversations and much more, with granular configuration. For more details on using Comodo Backup application, please refer to the online guide at http://help.comodo.com/topic-9-1-281-2732-Comodo-BackUp-Introduction.html.

Watch falling skies online free