Why Linux?

If you are reading this article then you must be using windows or something else. I just want to say use Linux then you will love to wright an article like this. There are several causes why use Linux but I will mention a few.

Best thing in Linux:

1. Linux based on open source system, so it's free. So why spend money when you get best things free. Almost every application is free in Linux. So there is nothing between you and pure pleasure of computing.
2. Security: One small word but it's mean a lot. Virus, malware, spyware are almost useless in Linux. There several security protocols implemented in Linux which makes it self insensible.
3. Stable, Reliable and extremely powerful: Linux is one of the most stable system in OS world. It's open source so millions of people working and re-moderating as per our need. So, Linux used by most of the research and development sector.
4. I a haven for programer and developer. Linux support almost any type of software development environment. There are no other mach for development.
5. Install and updatability: There are two separate panels dedicated for these work If you want to install or update app, you need to click 1 or 2 times or a single commend can do it more easily. 
6. Fast: Linux app size is smaller than other OS so it work faster than other. Not only app size but also architecture of Linux make it faster.
7. Easy to use: What could be easier than opening a package manager, selecting the software you want, and letting Linux download it for you. It's a highly synchronized system. Just use it and you will realize that this is true.
8. Substitute: If there are some application you are habituated with in windows you can use wine and continue using windows software in Linux.
9. Looks: Now days Linux enhanced with graphics and animations. Windows even can't compete with its present look.
10. I can give you more the thousand causes in favor of Linux but I tell you to use Linux and proud to be a Linux user because we should . . .

Schedule a Task with 'at' command

Linux provides a really easy way to schedule future events so they run automatically. We can use the 'at' command to schedule reminders or administrative tasks or to run a command later when the computer won't be busy. 
 
After we specify the time (and optional date) for your event, at prompts you for the command to run. After entering your command, press ctrl-D to finish.  

Syntax:

at TIME [ DATE ]

Here are some examples:

at 8:15am Jul 14

echo "Remember to call"

^D

at midnight Monday

cp project/source backup

^D

To find out what events you have already scheduled with at, enter the following:

at -l
Date Owner Queue Job#
08:15:00 07/14/97 root c 1
00:00:00 01/10/97 root c 2

To cancel an event scheduled with at, use the -r switch and a job number (which you can find using the at -l command). For example, to cancel job 2, you would ent er

at -r 2

at now + 5 minutes < $HOME/listofcommands.txt

The Linux at command argument time can be one of the following:

• HH:MM format — For example, 04:00 specifies 4:00AM. If the time is already past, it is executed at the specified time the next day.

• midnight — Specifies 12:00AM.

• noon — Specifies 12:00PM.

• teatime — Specifies 4:00PM.

• month-name day year format — For example, January 15 2002 specifies the 15th day of January in the year 2002. The year is optional.

• MMDDYY, MM/DD/YY, or MM.DD.YY formats — For example, 011502 for the 15th day of January in the year 2002.

• now + time — time is in minutes, hours, days, or weeks. For example, now + 5 days specifies that the command should be executed at the same time in five days.

=> at - executes commands at a specified time.

=> atq - lists the user's pending jobs, unless the user is the superuser; in that case, everybody's jobs are listed. The format of the output lines (one for each job) is: Job number, date, hour, job class.

=> atrm - deletes jobs, identified by their job number.
batch executes commands when system load levels permit; in other words, when the load average drops below 1.5, or the value specified in the invocation of atrun.

Upgrade Fedora 15 to 16

I found 'preupgrade' is the best tool to upgrade you system. You can download fedora image from it's site and or you can use upgrade commands or you can use preupgrade tool to update your fedora15 to fedora16.

First update your system:

$ su             //enter super user password

$ yum update

Verify the upgrade:

$ yum repolist

$ yum distro-sync

Then install preupgrade:

$ yum install preupgrade

Start preupgrade:

$ preupgrade

The best part of preupgrade is you can stop your download any time and it resume downloading on start next time.

After complete all five steps the computer will restart and upgrade old system but it will take some time. So, Enjoy Fedora16 . . . 

Try overview of fedora 16