Computers: Automating Tasks in Linux using Cron

Automating Tasks in Linux using Cron

Written by Vinu Thomas

Linux has a powerful task scheduler called Cron. Cron will allow you to run commands automatically at times specified by you. Cron is similar to repparttar

task scheduler you find in Windows. To keep track of repparttar 107744

schedules and tasks it has to run, Cron requires a file called Crontab (CRON TABle). All repparttar 107745

Cron schedules and tasks should be stored in this table. The Crontab files cannot be directly edited. You can add or delete entries in repparttar 107746

crontab file using repparttar 107747

crontab command.

What's Cron and Crontab ?

You must be wondering what repparttar 107748 difference between cron and crontab or wether they are repparttar 107749 same. Cron is a process or program which wakes up every minute and looks for jobs it has to execute at that moment. Crontab is repparttar 107750 list of jobs and times at which they have to execute.

Crontab Format:

Each entry in Crontab has at least 6 fields separated by a single space. Field 1 Minute Range of Values : 0-59 Field 2 Hour Range of Values : 0-23 Field 3 Day Range of Values : 1-31 Field 4 Month Range of Values : 1-12 Field 5 Day of week Range of Values : 0-6 (Sunday being 0) Field 6 Command to Execute

Now let's see how to make a crontab entry. Let's say you want to run a script backup.sh every day at 6:00pm.The entry would look like this:

0 18 * * * /home/user/backup.sh

The asterisk (*) is used to indicate that every instance of repparttar 107751 particular time period will be used (i.e. every hour, every weekday, etc.). I've used to full path to repparttar 107752 script /home/user/backup.sh instead of just using backup.sh. This is because cron runs as root, you should fully qualify your path names to any scripts that will be run. Let's see some more examples :

* Let's run repparttar 107753 script printinvoices.sh every sunday at 12:45pm.

45 12 * * 0 /home/account/printinvoices.sh

* How about clearaccount.sh every month beginning at 1:32am ?

Internet Explorer Shortcuts

Written by Rick Yost

Internet Explorer is repparttar

most useful free browser on repparttar 107743

net. Here are a few Explorer tips I find useful.

To search for a particular word or phrase on a web page just press CTRL + F to open repparttar 107744 Find dialog.

Hold down repparttar 107745 shift key when you click a link to have it open in a new window. If you know you're coming back to repparttar 107746 same page, a new window is faster to open and close than backtracking pages.

Hit repparttar 107747 Backspace key on your keyboard to go back a page, or press ALT + repparttar 107748 Left Arrow. ALT + repparttar 107749 Right Arrow goes forward a page, and ALT + Home take you to your home page.

Hit repparttar 107750 Spacebar to jump down repparttar 107751 page one screen length. Hold repparttar 107752 shift key down as you press repparttar 107753 Spacebar to jump UP repparttar 107754 page. Use repparttar 107755 Up and Down Arrows to scroll slower.

In IE 5.5, in most cases you can just type "domain_Name.com" instead of typing repparttar 107756 "www" first. IE knows to search for it on repparttar 107757 web. Works for most sites, but a few can't be found without repparttar 107758 www - that's a server issue, not an IE issue.

CTRL + O opens repparttar 107759 dialog to type in a web address.

Press repparttar 107760 F11 key to open your browser into full screen mode. Press it again to leave full screen mode.

Right-click repparttar 107761 tool bar and select Auto-hide. This hides repparttar 107762 tool bar for true full screen surfing. To use repparttar 107763 hidden tool bar, just move your mouse to repparttar 107764 top edge of repparttar 107765 screen. Move your mouse away and it disappears again. You can do this with your taskbar too, by clicking repparttar 107766 Start button, pointing to settings, and clicking Taskbar & Start Menu. Then place a check by repparttar 107767 Autohide feature and click Apply.

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