Showing posts with label Linux. Show all posts
Showing posts with label Linux. Show all posts

Critical Linux Flaws

Last week three new vulnerabilities were announced by Polish security firm iSec Security Research in the latest Linux kernel which could allow an attacker to elevate their privileges on the machine and execute programs as the root administrator.

These are just the latest in a series of serious or critical security vulnerabilities discovered in Linux over the past few months. The board room at Microsoft is probably getting some amusement, or at least feeling some relief, from the irony that open source is supposed to be more secure and yet these critical flaws continue to be found.

It misses the mark though in my opinion to claim that open source software is more secure by default. For starters, I believe that the software is only as secure as the user or administrator who configures and maintains it. Although some may argue that Linux is more secure out of the box, a clueless Linux user is just as insecure as a clueless Microsoft Windows user.

The other aspect of it is that the developers are still human. Out of the thousands and millions of line of code that make up an operating system it seems fair to say that something might get missed and eventually a vulnerability will be discovered.

Therein lies the difference between open-source and proprietary. Microsoft was notified by EEye Digital Security about the flaws with their implementation of ASN.1 eight months before they finally announced the vulnerability publicly and released a patch. Those were eight months during which the bad guys could have discovered and exploited the flaw.

Open source on the other hand tends to get patched and updated much faster. There are so many developers with access to the source code that once a flaw or vulnerability is discovered and announced a patch or update is released as quickly as possible. Linux is fallible, but the open source community seems to react much quicker to issues as they arise and respond with the appropriate updates much quicker rather than trying to bury the existence of the vulnerability until they get around to dealing with it.

That said, Linux users should be aware of these new vulnerabilities and make sure they stay informed of the latest patches and updates from their respective Linux vendors. One caveat with these flaws is that they are not exploitable remotely. That means that to attack the system using these vulnerabilities requires the attacker to have physical access to the machine.

Many security experts agree that once an attacker has physical access to a computer the gloves are off and almost any security can be eventually bypassed. It is the remotely exploited vulnerabilities- flaws that can be attacked from systems far away or outside of the local network- that present the most danger.

For more information check out the detailed vulnerability descriptions from iSec Security Research to the right of this article.


View the original article here

Unix / Linux File Permissions

Unix and Linux operating systems assign access rights to files and directories using one of three types of access (read, write and execute) assigned to each of three groups (owner, group and other users).

If you list details of a file's attributes using the ls command with the -l switch (for example ls -l filename), it would return information that would look something like -rwe-rw-r-- which equates to read, write and execute privileges for the owner, read and write privileges for the group and only read access for all other users.

Each of the types of access rights has an associated numeric value listed below: read = 4 write = 2 execute = 1

The values for the access rights for each of the groups is added together to obtain a value between 0 and 7 which can be used to assign or modify permissions using the chmod (change mode) command.

In the example above, the access rights for the file in question could be assigned by entering chmod 764 filename. The number 764 is derived from: rwe = 4 (read) + 2 (write) + 1 (execute) = 7 rw = 4 (read) + 2 (write) = 6 r = 4 (read) = 4 You can use the chmod command to assign access rights to files and directories. Keep in mind that Unix and Linux commands and object names are case sensitive. You must use "chmod" and not CHMod or any other combination of upper and lower case letters.

Below are some other examples of how to use the chmod command: full access for everybody:
chmod 777 filename full access for owner and group privileges but other users can only read and execute:
chmod 775 filename full access for owner, but restricting group and other user privileges to only read and execute for files in the directory:
chmod 755 dirname full access for the owner with no access rights or privileges for anyone else:
chmod 700 filename no access to files in directory for group or other users and owner restricted to read and execute privileges to prevent the accidental deletion or modification of files in the directory:
chmod 500 dirname allowing the owner and group read and write access to a file, allowing others in the group to edit or delete the file as well as the owner, but with no access for other users:
chmod 660 filename

View the original article here

Primary Advantages of Linux

When compared to various commercially available operating systems, Linux�s best assets are its price, its reliability, and the freedom it gives you. With the latest 2.6 Linux kernel, you can also argue that scalability is one of its greatest assets. Today, Linux is used in the New York Stock Exchange, banks, highly secure U. S. government installations, and many other institutions for which uptime, security, and performance are critical. It�s also used in hand-held devices, netbooks, and commercial TV video recorders.

Most people know that its initial price is free (or at least under $50 when it comes in a box or with a book). However, when people talk about Linux�s affordability, they are usually thinking of its total cost, which includes no (or low) licensing fees, the ability to reuse any of the code as you choose, and the capability of using inexpensive hardware and compatible add-on applications that are free to download and use. Although commercial operating systems tend to encourage upgrading to more powerful hardware, Linux doesn�t require that (although faster hardware and larger disks are nice to have).

In terms of reliability, the general consensus is that Linux is comparable to many commercial UNIX systems but more reliable than most desktop-oriented operating systems. This is especially true if you rely on your computer system to stay up because it is a Web server or a file server. (You don�t have to reboot every time you change something, unless you�ve replaced the kernel itself.).

This reliability also extends into the realm of safety. While there have been exploits aimed at Linux software, Linux users are for the most part safe from the culture of malware and viruses that plague Windows users. With so many people peering at the Linux source code, a benefit of its freedom, mistakes are often fixed in record time. Large-scale Linux deployments don�t need to install anti-virus software, a situation you would never allow with Windows in a corporate setting. Furthermore, when people install anti-virus software on Linux, it is usually to scan files and e-mail messages for Windows viruses, to help the distraught users of Windows.

Because you can get the source code, you are free to change any part of the Linux system, along with any open source software that comes with it, in any way that you choose. Unlike many self-contained commercial products, open source software tends to be built in pieces that are meant to interact with other pieces, so you are free to mix and match components to suit your tastes. As I mentioned earlier, Linux is a culture that encourages interoperability. For example, if you don�t like a window manager, you can plug in a different one because so many were built to operate within the same framework.

Another advantage of using Linux is that help is always available on the Internet. There is probably someone out there in a Linux newsgroup or mailing list willing to help you get around your problem. Because the source code is available, if you need something fixed you can even patch the code yourself! On the other hand, I�ve seen commercial operating system vendors sit on reported problems for months without fixing them. Remember that the culture of Linux is one that thrives on people helping other people.

Source of Information :  Wiley - Adobe Fedora Bible 2010 Edition Featuring Fedora Linux

Common Linux Features

No matter what distribution of Linux you use, the piece of code common to all is the Linux kernel. Although the kernel can be modified to include support for the features you want, every Linux kernel can offer the following features:


� Multiuser � Not only can you have many user accounts available on a Linux system, you can also have multiple users logged in and working on the system at the same time. Users can have their own environments arranged the way they want: their own home directory for storing files and their own desktop interface (with icons, menus, and applications arranged to suit them). User accounts can be password-protected, so that users can control who has access to their applications and data.


� Multitasking � In Linux, it is possible to have many programs running at the same time, which means that not only can you have many programs going at once, but that the Linux operating system can itself have programs running in the background. Many of these system processes make it possible for Linux to work as a server, with these background processes listening to the network for requests to log in to your system, view a Web page, print a document, or copy a file. These background processes are referred to as daemons.


� Hardware support � You can configure support for almost every type of hardware that can be connected to a computer. There is support for floppy disk drives, CDs, removable disks (such as DVDs and USB flash drives), sound cards, tape devices, video cards, and most anything else you can think of. As device interfaces, such as USB and FireWire, have been added to computers, support for those devices has been added to Linux as well.

For Linux to support a hardware device, Linux needs a driver, a piece of software that interfaces between the Linux kernel and the device. Drivers are available in the Linux kernel to support hundreds of computer hardware components that can be added or removed as needed.


� Networking connectivity � To connect your Linux system to a network, Linux offers support for a variety of local area network (LAN) network interface cards (NICs), modems, and serial devices. In addition to LAN protocols, such as Ethernet (both wired and wireless), all the most popular upper-level networking protocols can be built-in. The most popular of these protocols is TCP/IP (used to connect to the Internet). Other protocols, such as IPX (for Novell networks) and X.25 (a packet-switching network type that is popular in Europe), are also available.


� Network servers � Providing networking services to the client computers on the LAN or to the entire Internet is what Linux does best. A variety of software packages are available that enable you to use Linux as a print server, file server, FTP server, mail server, Web server, news server, or workgroup (DHCP or NIS) server.


To make a Linux distribution useful, components need to be added on top of the Linux kernel. For humans to access a Linux system, they can enter commands to a shell or use graphical interfaces to open menus, windows, and icons. Then you need actual applications to run. In particular, a useful Linux desktop system includes the following:


� Graphical user interface (X Window System) � The powerful framework for working with graphical applications in Linux is referred to as the X Window System (or simply X). X handles the functions of opening X-based graphical user interface (GUI) applications and displaying them on an X server process (the process that manages your screen, mouse, and keyboard).

On top of X, you use an X-based desktop environment to provide a desktop metaphor and window manager to provide the look-and-feel of your GUI (icons, window frames, menus, and colors, or a combination of those items called themes). There are a few desktop environments and and even more window managers to choose from. (Fedora focuses on the GNOME and KDE desktop environments, but also has several other desktop environments, such as Xfce, and window managers, such as Blackbox and AfterStep, available. )


� Application support � Because of compatibility with POSIX and several different application programming interfaces (APIs), a wide range of free and open source software is available for Linux systems. Compatibility with the GNU C libraries is a major reason for the wide-ranging application support. Often, making an open source application available to a particular version of Linux can be done by simply recompiling the source code to run on that Linux version.

Source of Information :  Wiley - Adobe Fedora Bible 2010 Edition Featuring Fedora Linux

Linux�s Roots in UNIX

Linux grew within a culture of free exchange of ideas and software. Like UNIX � the operating system on which Linux is based � the focus was on keeping communications open among software developers. Getting the code to work was the goal and the Internet was the primary communications medium. Keeping the software free and redistributable was a means to that goal. What, then, were the conditions that made the world ripe for a computer system such as Linux?

In the 1980s and 1990s, while Microsoft flooded the world with personal computers running DOS (Disk Operating System) and Windows operating systems, power users demanded more from an operating system. They ached for systems that could run on networks, support many users at once (multiuser), and run many programs at once (multitasking). DOS and Windows didn�t cut it.

UNIX, on the other hand, grew out of a culture where technology was king and marketing people were, well, hard to find. Bell Laboratories in Murray Hill, New Jersey, was a think tank where ideas came first and profits were somebody else�s problem. A quote from Dennis Ritchie, co-creator of UNIX and designer of the C programming language, in a 1980 lecture on the evolution of UNIX, sums up the spirit that started UNIX. He was commenting on both his hopes and those of his colleagues for the UNIX project after a similar project called Multics had just failed:

What we wanted to preserve was not just a good environment in which to do programming, but a system around which a fellowship could form. We knew from experience that the essence of communal computing as supplied by remote-access, time-shared machines, is not just to type programs into a terminal instead of a keypunch, but to encourage close communication.

In that spirit, the first source code of UNIX was distributed free to universities. Like Linux, the availability of UNIX source code made it possible for a diverse population of software developers to make their own enhancements to UNIX and share them with others.

By the early 1980s, UNIX development moved from the organization in Murray Hill to a more commercially oriented development laboratory in Summit, New Jersey (a few miles down the road). During that time, UNIX began to find commercial success as the computing system of choice for applications such as AT&T�s telephone switching equipment, for supercomputer applications such as modeling weather patterns, and for controlling NASA space projects.

Major computer hardware vendors licensed the UNIX source code to run on their computers. To try to create an environment of fairness and community to its OEMs (original equipment manufacturers), AT&T began standardizing what these different ports of UNIX had to be able to do to still be called UNIX. To that end, POSIX standards and the AT&T UNIX System V Interface Definition (SVID) were specifications UNIX vendors could use to create compliant UNIX systems. Those same documents also served as road maps for the creation of Linux.

Elsewhere, the UNIX source code that had been distributed to universities had taken on a life of its own. The Berkeley Software Distribution (BSD) began life in the late 1970s as patches to the AT&T UNIX source code from students and staff at the University of California at Berkeley. Over the years, the AT&T code was rewritten and BSD became freely distributed, with offshoot projects such as FreeBSD, OpenBSD, and NetBSD still available.

Linux has been described as a UNIX-like operating system that reflects a combination of SVID, POSIX, and BSD compliance. Linux continues to aim toward POSIX compliance, as well as compliance with standards set by the new owner of the UNIX trademark, The Open Group (http://www.unix.org). Much of the direction of Linux today comes from the
Linux Foundation (http://www.linuxfoundation.org), which was founded in 2007 by a merger of the Free Standards Group and the Open Source Development Labs.

Source of Information :  Wiley - Adobe Fedora Bible 2010 Edition Featuring Fedora Linux

Pinguy OS: Linux For Dummies

It�s an old trope, one that has almost entirely lost its meaning over time, but there�s another Linux distro that is designed for the average (or slightly below average) computer user.

This one, however, is about as close as any have come to creating an idiot-proof Linux distro. Pinguy OS (www.pinguyos.com) is based on Ubuntu and is mighty fun to play with.


A Little Background
Pinguy OS was built by a fellow named Antoni Norman who wanted a Linux OS that he could give to friends and family�without having to constantly provide tech support. He�d been recommending Ubuntu but grew frustrated with how stark it was. Even though it�s relatively easy to add software, codecs, and the like with Ubuntu�s repositories, he found that many novice users were still having trouble finding everything they needed to make their system work as they wanted it to.

He looked at what his family and friends wanted to do with their computers, determined which applications would satisfy those needs in the most userfriendly way possible, and then decided to install those applications along with anything needed to make them run properly.

Along the way, Norman hit on an interesting problem with Linux repositories: It�s great that virtually any and every application you could possibly want is right there for the taking, but most users don�t know which applications they really want or need.

For example, everyone wants a wordprocessing application, a photo editor, a music player, and so on, but which one should you choose? The options can be overwhelming. Pinguy OS is kind of like having a personal shopper; you still have 50 choices for spaghetti sauce, but Pinguy OS more or less removes the decision-making process for you.

Pinguy OS is a simple and smart, if slightly counterintuitive, approach to a Linux distro. Instead of giving the user his or her own tabula rasa operating system as the user-friendly Ubuntu does, Pinguy OS packs in all the programs, patches, browser plug-ins, and other tweaks that (he�s pretty sure) the average user will want, and it�s all designed to be optimized from the get-go. He also used a variety of programs to tweak the interface so it�s as attractive as possible, such as using MintMenu for the main menu. The result is an operating system that should �just work� and looks pretty, to boot.


A Tour
It was somewhat jarring to boot a Linux OS and be greeted by a relatively busy desktop. On the left side of the screen is a vertical dock with folders for documents, music, pictures, and so on, and another dock on the bottom of the screen displays applications. Docky (which, as it happens, created both on-screen docks), Firefox, Mozilla Thunderbird, the Deluge BitTorrent client, Rhythmbox, VLC media player, Terminal, and a trash can are pinned to the dock (again, created by Docky) by default, but it also displays any open applications.

The top of the screen has a straightforward file menu (not created by Docky), which contains Places, System, Applications, and Search; Desktop, with a Spotlight-like search bar; and the predictable File, Edit, View, Places, and Help.

One item that seems to clash a bit with Pinguy�s raison d��tre is the large, transparent widget that displays information about CPU usage and other under-the-hood information about your system. Although this is a nice tool for knowledgeable computer users, Pinguy OS�s target audience probably won�t even know what it�s for, and it takes up a lot of screen space. It seems rather unnecessary.


Test Drive
For the most part, Pinguy OS is as advertised. Everything is intuitive, smooth, and responsive, and I was able to watch streaming video from a number of sites without having to install anything. (Netflix streaming was a nogo, however.) Little things make the overall experience enjoyable, such as the use of Elementary-Nautilus to pull album art meta data into Rhythmbox.

Although Norman set up Pinguy OS to open a given file in the �right� program, it didn�t always work that way. For example, video opens in VLP Player and images open in Image Viewer by default, which is great, but my test MP3 files opened in Movie Player for some reason. (A similar oddity occurs when you connect an iOS device�the system didn�t recognize an iPod as a music player, although it worked fine after forcing the system to open it in Rhythmbox.) It�s not difficult to change those settings, but the whole point of Pinguy OS is that you shouldn�t have to.

Some of the chosen applications make a lot of sense. For example, the office application (OpenOffice), Web browser (Firefox), and email application (Thunderbird) are great options. However, there seem to be a few applications with overlapping functions that add to the already large number of programs. Do we really need the Deluge and TED BitTorrent clients; Dropbox and Ubuntu One for online storage; Brasero and DeVeDe to burn discs; and GNOME MPlayer, VLC, and Rhythmbox to play media, to name a few?

At the same time, Pinguy OS is smart about efficiency in other areas. For example, under Gaming, instead of littering the section with a dozen casual games, Pinguy OS has just one entry: PlayOnLinux, which lets you play a lot of PC gaming titles on your Linux machine.


In Sum
What�s somewhat amusing about Pinguy OS is that it has a certain Mac feel to it. It�s pretty, it makes heavy use of docks, and everything is all set up for you ahead of time. Further, for the most part, it removes the need for people to choose which programs to use.

This is a terribly un-Linux-like approach and no doubt drives some purists crazy, but that�s OK because, of course, Pinguy isn�t for the purists. It�s designed to reach out a bit further than even Ubuntu does, to the less-experienced user looking for a bona fide OS option beyond Mac or Windows machines. In fact, Pinguy OS is a rather logical evolution for many people looking to get on the open-source bandwagon (or people trying to convince others to do so).

Hopefully, Norman will continue to work on Pinguy OS and the open-source community will continue to support it. It�s well worth the effort.

Source of Information :  Computer Power User (CPU) January 2011

An Ecosystem of Distributions

Many hundreds of GNU/Linux distributions are in active use today. A quick look at Distrowatch�s database (distrowatch.com) demonstrates the staggering number and growth of distributions. One of the first GNU/Linux distributions was called Softlanding Linux System, or SLS. For a number of reasons, a programmer named Patrick Volkerding thought he could improve on SLS. Because SLS was free software, Volkerding had the freedom to make a derivative version of SLS and distribute it. Volkerding did just this when he took SLS�s code and used it as the framework or model upon which to create his own variant called Slackware. Subsequently, Slackware became the first widely successful GNU/Linux distribution and is maintained to this day.

With time, the landscape of GNU/Linux distribution has changed. However, the important role of derivation that made Slackware possible has remained fully intact and is still shaping this landscape. Today, the hun dreds of GNU/Linux distributions serve a multitude of users for a myriad of purposes: There are distributions specially designed for children, for dentists, and for speakers of many of the world�s languages. There are distributions for science, for business, for servers, for PDAs, for nonprofit organizations, for musicians, and for countless other groups.

Despite this diversity, the vast majority of derivatives can be traced back to one of two parent distributions: Red Hat and Debian. While it is not necessary to understand the details of how these projects differ, it�s useful to know that Red Hat and Debian offer two compelling, but frequently different, platforms. Each project has strengths and weaknesses. For almost every group making a Linux-based OS, one of these projects acts as square one (with a few notable exceptions, such as the Gentoo project).

However, while the process of deriving distributions has allowed for a proliferation of OS platforms serving a vast multiplicity of needs, the derivative process has, historically, been largely a one-way process. New distributions based on Red Hat�Mandriva and Novell�s SUSE, for example�begin with Red Hat or a subset of Red Hat technology and then customize and diverge. Very few of these changes ever make it back into Red Hat and, with time, distributions tend to diverge to the point of irreconcilable incompatibility. While the software that each system includes remains largely consistent across all distributions, the way that it is packaged, presented, installed, and configured becomes increasingly differentiated. During this process, interdistribution sharing and collaboration grow in difficulty.

This growing divergence indicates a more general problem faced by distribution teams in getting changes upstream. Frequently, the users of GNU/Linux distributions find and report problems in their software. Frequently, distribution teams fix the bugs in question. While sometimes these bugs are in changes introduced by the distribution, they often exist in the upstream version of the software and the fix applies to every distribution. What is not uncommon, but is unfortunately much less frequent, is for these bug fixes to be pushed upstream so that all distributions and users get to use them. This lack of collaboration is rarely due to malice, incompetence, or any tactical or strategic decision made by developers or their employers. Instead, tracking and monitoring changes across distributions and in relation to upstream developers is complicated and difficult. It�s a fact of life that sometimes changes fall on the floor. These failures are simply the product of distribution-building processes, policies, and tools that approach distributions as products in and of themselves�not processes within an ecosystem.

Like many other distributions, Ubuntu is a derivative of Debian. Unlike the creators of many derivatives, the Ubuntu community has made it one of its primary goals to explore the possibility of a better derivation process with Debian, with Debian and Ubuntu�s common upstreams (e.g., projects such as Linux or GNU), and with Ubuntu�s own derivatives. A more indepth discussion of Debian can help explain how Ubuntu positions itself within the free software world.

Source of Informaion : Prentice Hall The official Ubuntu Book 5th Edition 2010

A Brief History Of Linux Text Editors

Years ago, text files were primarily used for system administration-related files, such as startup scripts and configuration files. But as computers evolved, people began using text files to write essays and term papers for school work. However, once the home computing market grew and word processors came onto the scene, those text files were once again relegated to system administration functions. It is in this environment that text editors such as the MS-DOS Editor and Windows Notepad were created.

Although text files are still used for system administration purposes, they�ve taken on a new purpose. Specifically, text files are used to create all sorts of tools, from desktop programs to sophisticated Web pages. To be sure, programmers creating desktop programs use programs that give a complete development environment, but the core of that environment has a specialized text editor that lets the user write the actual program. The code that is created to make those programs is just a text file. Sufficiently complicated programs and Web pages may use many different files, but the vast majority of them are text files.

There is a wide variety of text editors for Linux. Whether it�s editing a system file or managing a large-scale programming project, there�s a Linux text editor for you.


Default Text Editors
Notepad for Windows is the very definition of a basic text editor. You can edit one file at a time and view files with long lines wrapped or not. Find and Replace is its most powerful feature. This is fine if all you want to do is make little edits to a set of instructions, for example, or if you�re taking a quick note. But because text files are so widely used in the Linux world, its text editors necessarily have to be more powerful.

GNOME and KDE are two of the more popular desktop environments in the Linux community, and each includes its own text editor. GNOME has gedit, while KDE offers Kate; both editors share similar features. KDE actually has an older, less powerful text editor, called Kwrite, but its development has been folded into Kate. In fact, some Linux distributions bypass Kwrite altogether, instead just installing Kate.

Kwrite can best be described as a little bit more advanced than Notepad. Like Notepad, Kwrite only lets you edit one file at a time per window. (Of course, if you don�t mind the desktop clutter, you can launch multiple instances of Kwrite to edit multiple files, just like Notepad.) Where Notepad�s most advanced feature is Find and Replace, Kwrite also has a spell checker. So if all you need is a minimal text editor with spell check capability, Kwrite may be right up your alley. If you�re looking for more power, use Kate.

Generally speaking, you should use gedit and Kate, as they offer a lot more features�not only for general text editing but also for lightweight programming. Both editors let you edit multiple files at the same time in a single window. Kate shows the files in a list
view down the left side, while gedit shows your open files in a tabbed view across the top.

But, more importantly, both gedit and Kate have syntax highlighting. What this means for programmers is that these editors will display different bits of code in different colors. For example, variables used in your code may appear in one color, values appear in a second, comments appear in a third, and so on. This makes it very easy to see how everything is laid out in your code.

Another particularly useful feature that gedit and Kate share is the ability to extend the editor with plug-ins. These plug-ins can do all sorts of things, from manipulating text in the file to running external commands. For example, there are plug-ins for gedit and Kate that turn each into an SQL client for database connectivity. If you�re writing a lot of database code, this plug-in is ideal to verify that your SQL queries work correctly while you�re coding.


Cross-Platform Editors
Beyond gedit and Kate, there are a number of text editors that exist on both Linux and other platforms. Most of these editors are open source, so it�s no surprise that they are able to run on different platforms.

But because of Windows� popularity in the operating system market, there are a lot of Windows-only text editors. What happens if you�re a fan of one of these editors but want to be able to run it on Linux? Although you can use WINE to run many of the Windows-native editors in Linux, some developers have created Linux versions of their respective editors.

One prominent example is UltraEdit (www.ultraedit.com), a highly regarded commercial text editor for Windows. IDM Computer Solutions, the makers of UltraEdit, recently released a Linux version of its text editor. Versions ready to install and run are available for the following Linux distributions: Ubuntu, Fedora, openSUSE, and RedHat. For users of other Linux distributions, a generic precompiled binary is also available as a Gzipped TAR file.


Console Text Editors
Although we�ve been discussing text editors, we�ve primarily focused on the graphical text editors. Long before there were graphics, text editors were consolebased. These editors worked fine but often had cryptic keystrokes. As a result, they usually presented novices with a steep learning curve. With the advent of the modern desktop, you may wonder why anybody would continue bothering with console text editors.

One reason is that system administrators, like programmers, tend to be creatures of habit. So once they find a tool they like, they usually stick with it for as long as possible; that includes text editors. An example of how devoted people are to tools they like can be seen in ed, which is an early 1970s Unix text editor. It survives to this day in the Linux world, as you would expect, and the Windows world.

Another reason why people still use console text editors is that they�re more universally available. Sure, GNOME and KDE come with their graphical text editors, but in some environments, you won�t have access to the GUI. Some corporate security policies will specifically allow only remote console access to sensitive systems. In these cases, you have no choice but to use a console text editor.

There are a number of very powerful console text editors, each with its own strengths and weaknesses. In fact, before there were the operating system debates, Web browser debates, or smartphone debates, there were the text editor debates. People used to argue vehemently that their favorite console text editor was better than someone else�s.

One such popular text editor is vi, which works in two modes, Insert Mode and Command Mode. On most Linux distributions, vi has been replaced by Vim, which is very similar, but not identical, to vi. In vi�s Insert Mode, whatever you type on the keyboard is inserted into the file you�re editing. To start vi�s Insert Mode, you have to press I, to insert text, or O to create a new blank line and start inserting text. When you�re done inputting text, press ESC to start Command Mode. While in Command Mode, you can move around the file with the arrow keys and delete characters with the X key. When you�re done working with a file in vi, you have to go into Command Mode and type :wq. This will write the file to disk and close vi.

Certainly, vi is much more powerful than such a brief introduction we�ve given it. It has search and replace capability, either globally or within a certain range, the ability to save part of a file as another file, and macro capability. In fact, vi�s macro capability is so complex that it is able to let the user play simple games with it.

Text editors fill an important need in the world of Linux systems administrators and programmers. And Linux has a very good selection of editors.

Source of Information : Computer Power User (CPU) December 2010    
 
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