The Linux users' guide Linux(R) Troubleshooting for System Administrators and Power Users Z Vm and Linux Operations for Z Os System Programmers. Linux for Programmers and Users - Ebook download as PDF File .pdf), Text File .txt) or read book online. Linux. An overview of Linux, the kernel, the C library, and the C compiler. • Reading from With Linux System Programming, you will be able to take an in-depth look at Linux from both a theoretical Real, Effective, and Saved User and Group IDs.

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4th Edition, M, pdf. John Wiley & Sons - Linux Bible, Edition, M, pdf Linux for Programmers and Users By Graham Glass, King Ables, M, chm. So if you are a Linux User, you might be using Ubuntu, Arch Linux, Manjaro, All the mentioned Linux Tutorial books originally come with a pdf version, and I IBM Developer Kit for Linux, Java 2 Technology Edition; The GNU Compiler for. The Linux Programmer's Guide is c , by Sven Goldt ber he released the first prototype by e-mail to some other Minix users on the internet.

It also explains how to make the most effective use of the GIMP tools for touchup, compositing, 3D rendering and the presentation of graphics on the Web. Available both for online viewing and as an HTML download.

A wide ranging look at the development of operating systems for personal computers. Although the emphasis is on Microsoft Windows and the Macintosh, this material could be of interest to many Linux users and developers as well.

Available for online viewing and downloading in. Gough, An overview for new users but also suitable for more advanced trainees as a desktop reference. There are many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant.

The first edition of this O'Reilly book. The fourth edition of this O'Reilly book. Part of the Linux Documentation Project, this work describes day-to-day administration and maintenance issues commonly faced by system administrators. This O'Reilly book is not just about writing device drivers but also about the Linux kernel as well. Linux Dictionary - by Binh Nguyen. Available for online viewing and in downloadable forms. Linux From Scratch, Version 5.

Step-by-step instructions for assembling a minimalist Linux distribution using only the source code for the kernel, utilities and a few other small programs. Working through this project takes considerable time and persistence, but the reward is a better understanding of what makes Linux tick, including how things work together and depend on each other.

Constructing a Linux distribution from scratch also makes possible 1 a high degree of customization, 2 a very compact system and 3 tight control over security. Available for viewing online and also downloadable in several formats.

This well written and useful although somewhat dated book is available for viewing online on The Linux Documentation Project website.

The Linux kernel - by Andries Brouwer, Linux Kernel 2. This introduction to the Linux 2. It is part of the Linux Documentation Project and can be viewed online and downloaded in various formats. A book for dedicated kernel hackers that begins gently with an explanation of kernel modules and the traditional "Hello World" programming example. Covers Linux system administration for popular distributions including Red Hat and Debian.

Suitable for use as a tutorial for new users and as a reference for experienced administrators. Mesman, Piet W.

Plomp and Willem A. Schreuder, The Linux Professional Institute Certification exam differs from Red Hat's exam in that it is completely vendor independent and distribution neutral and that it is developed and conducted by an independent, non-profit corporation. Bailey, RPM not only helped Red Hat Linux become the top distribution in just two years, but it has also been ported to several commercial Unix systems and is used by other commercial software companies.

An updated edition of the best-selling guide to the Concurrent Versions System, the most popular version control software for open source projects. Can be downloaded in PDF format. The first edition is available in multiple formats including online and downloadable HTML.

Jacobs, This page book treats parsing in great depth and covers almost all parsing methods, not just the popular ones.

A second edition is scheduled for release in Pocket Linux Guide - by David Horton, A guidebook for building a small diskette-based system called Pocket Linux from source code. Available for viewing online and downloadable in several formats. Emphasizes the fundamental concepts of programming languages including higher-order functions, data structures, mutable state, exceptions, objects and classes, and types as well as language implementations.

Available online as well as in downloadable text and PDF versions. Available in PDF format. Available for viewing online and for downloading in compressed form.

Wheeler, You may need to consult the specific installation guide to find out how to load SCSI drivers if Linux doesn't "see" the disks when it starts. Minimal system without many optional software applications MB to 1 GB Typical Linux workstation including common user applications 12 GB Linux workstation or server including many optional software packages 24 GB Full Linux installation including everything on GB depending on your installation media distribution selected Most Intel-based PC systems contain disk drives that use the Integrated Device Electronics IDE interface.

Many distributions of Linux initially default to using a x display for greatest compatibility with the greatest number of monitors and video cards. After Linux is installed. As with other hardware. The X Window System must be configured in a separate step after installation. The good news is that only a few distributions are widely deployed. This is the strength of Open Software. FeatherLinux can be booted from a USB pen drive.

While many more distributions exist than could be discussed here. Most of the distributions we survey here can be downloaded. Debian is a very reliable distribution and popular with experienced users. Although Debian has a reputation for being a bit hard to install. Debian has been ported to more different hardware platforms than most other distributions.

A great deal of information on these and many other distributions can be found at the following web sites: Linux distributions are available for all manners of boot media. The installation is text based rather than using a graphical interface. Once Debian is installed. Many large companies. Several distributions of Linux e. There are many options during Linux installation. Fedora Core is quite satisfactory. Mandrake was originally based on an early Red Hat distribution.

Mandrake is arguably the most popular distribution today. To avoid neglecting this large and loyal class of user. Fedora Core is listed as experimental and not for critical environments.

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Red Hat created an entity they named Project Fedora. For more information on Fedora Core and Red Hat. This success took Red Hat away from the smaller customer and individual Linux user.. Like most distribution creators. Fedora Red Hat. Mandrake Mandrake Linux is a commercial distribution.

The objective of Project Fedora is to provide a new distribution at a fast development pace. Red Hat has focused on business customers who wanted higher levels of support for enterprise applications. In business enterprise and other more critical environments. It also does a nice job of helping you decide which optional packages to install.

Fedora Core includes a nice graphical installation tool and is better than many other distributions at recognizing a variety of devices during installation. The distribution produced by Project Fedora is known as Fedora Core Linux and is popular due to its ease of installation and use. While Red Hat sponsors Project Fedora. Mandrake's popularity is largely due to its ease of installation. The installation process is text. It also includes its own package tool called pkgtool instead of RPM.

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To install. Volkerding while at Moorhead State University and he is still heavily involved today. Experienced users with whom Slackware is most popular appreciate that it doesn't clutter things up with a lot of "unnecessary" third-party code. What Slackware lacks in bells and whistles. Like Debian. This is probably one reason Mandrake is very popular with beginners. YaST performs the installation sometimes in text mode. It is a derivative of the Slackware distribution but with the typical additional features of a commercial distribution.

The installation tool is also helpful when selecting which optional packages to install. Somewhat like Debian. For more information on Mandrake Linux.

Slackware is a noncommercial distribution and tries to stay more traditional and closer to a "pure" Linux distribution. One way Slackware differs from most other Linux distributions is that it uses BSD-style boot scripts when booting instead of the more common System V style. The graphical installation program includes an excellent disk partitioning tool that can even shrink a Windows partition to make room for Linux more about that later.

Slackware Slackware Linux was the first distribution of Linux. For more information on Slackware. Mandrake also does excellent hardware detection. TurboLinux includes an easy-to-use installation program. For more information on TurboLinux. For more information on SuSE Linux. TurboLinux is a wholly owned subsidiary of Livedoor.

Linux users in other parts of the world will. TurboLinux is the leading supplier of Linux in the Asia Pacific region and is very popular there because of its excellent multibyte language support thus it runs well in Chinese. This consistency is comforting and provides a single place to do everything. Like many distributions. Unless you plan to use your Linux system as a server or only for command-line functions. Until mid Consider Optional Software Packages Once you decide which distribution you want.

Desktop Environments If you plan to run your Linux system as a graphical workstation. Where the X Window System provides the basic windowing functions and interfaces to the screen. Due to changes in the licensing. You may see either package. You can install additional packages later.

For more information on open source implementations of the X Window System. You don't have to decide on each and every package. You should consider things like whether you'll have a graphical workstation or a text-only interface. There are. Debate rages over which is "better. The differences are more in the philosophy of the designers and what problems they were trying to address.

Both come with most distributions of Linux. In the UNIX tradition. To greatly oversimplify. It is a user desktop as well as a development platform for graphical applications that can be written in a variety of languages. Both desktop environments provide a menu bar of useful applications.

Two desktop environments have emerged as the main players in Linux environments and are now used in many UNIX environments as well: On the surface.

Which you prefer is largely a matter of personal taste. Mandrake to KDE. While this gives many users. Some people don't like that KDE's roots were in some licensed software. Figure shows an example of a KDE desktop. It provides more applications specific to the KDE environment and tries to serve more purposes for more types of users. This item is displayed on page 26 in the print version [View full size image]. When installing Slackware Linux.

Linux for Programmers and Users

Networking If you are installing your Linux computer in an environment where it will be connected to a local network. If you want to install only one. Your network or systems administrator should be able to provide you with the information you need.

Most installation programs have a section where they let you set this information. If hosts on the network use DHCP to gather information about themselves when.

You can also define all the network-related information after installation is complete. If you plan to allow other computers to access the file systems on your Linux computer. Sun Microsystems sponsors and participates in the open source project OpenOffice. Office Tools A nice suite of office productivity tools is available with most distributions of Linux and if not.

Beginning Linux Programming

Based on Sun's StarOffice which cannot be completely released as open source due to licensing restrictions on parts of it. Some Linux distributions default to using IPv6 the latest version of the Internet Protocol networking protocol and in some environments this can actually cause performance problems.

If your network is still running IPv4 most probably do. A computer using DHCP sends out a broadcast as it boots up. Writer word-processing tool for reports. Draw drawing tool for everything from simple diagrams to 3D and specialized images Base database user tools that support dBASE. Java comes with many distributions. For more information about OpenOffice. If you must use a PC that already runs Windows.

Another option is to run Linux from within Windows. This way you don't risk losing any data by doing something wrong during the installation of Linux. The disk may contain only one partition the whole disk or it may be divided into smaller units. Some distributions can run Linux "live" off a CDKnoppix. Disk Partitioning If you plan to install Linux software on your hard drive. If you install Linux along with any other operating system.

Partitioning a disk is. If you. The ideal situation is that you have a PC that you no longer use and can put Linux on it. If you already have or can justify downloading a spare system. You can also put multiple distributions of Linux on a system if you have enough disk space and create a multiboot system.

Design Your System Now that you've decided what distribution and what tools to put on your system. I would strongly recommend going with a completely separate system. Only create a dual-boot system if you have the media to enable you to reinstall your original system should it become necessary.

If you make a mistake during the Linux installation. But you'll be happier later if you take a few minutes to think about what you need from your Linux system and design an appropriate plan. The most likely option is that you will install Linux on your system alongside Windows. Used computer stores sell older models at a fraction of the price of a new system.

Be sure the distribution you choose supports running directly from the CD without having to install files on the system.

A commercial product called VMware www. A partition is an area of the disk that is treated as a separate unit. If you could not reinstall and restore your original system on an empty disk. One other partition is required on a Linux system.

Nothing is stored in a swap partition. The simplest partitioning for a Linux system is to put the entire root file system in a single partition. This is useful when you need more than the four partitions that a partition table could support. You also have the option of creating other partitions for parts of the Linux file system. This is not a file system but rather a raw area on disk in which the kernel can "scribble. An extended partition has an entry in the partition table but points to a group of one or more logical partitions.

If you dual-boot or multiboot a system with more than one distribution of Linux. Every disk drive has a partition table. This spreads the swapping activity across different devices and will speed things up somewhat. Some partitioning tools don't even show you the difference between primary and extended partitions. This is known as the root file system.

You can use either type of partition: This partition is used by the virtual memory manager to swap data in and out of memory while the system is running. If you have two disk drives. If you have two empty disk drives on your system. A primary partition has an entry in the partition table and points to a fixed area on the disk.

Most partition tables allow four entries. When setting up one or more partitions for Linux to use.

By Graham Glass, King Ables

Partition Types Most disk drives support two types of partitions: Types of File Systems Many different file system implementations exist. For the purposes of installing Linux.

If you are really lucky. Most distributions of Linux come with several different file systems from which to choose. If you have a spare disk drive that Windows is not currently using. Partitioning for Linux and Windows If you must install Linux on a system where Windows is already installed.

All Linux distributions support these common file systems: Most Windows systems are installed using all of the disk space on the system. A file system is a data infrastructure that keeps track of file names and their associated data blocks in a hierarchical structure that makes it easy for humans to navigate around. Linux File Systems A partition is merely an area on the disk drive that can hold data. For Linux to be able to read and write directories and files.

This will involve shrinking the existing Windows partition to make room. Many PCs. Organization of File Systems The Linux directory tree. Most people choose ext2 linux native or ext3 unless they have a preference or a need for one of the more specialized file systems. The minimum amount of space in which you would ever want to install Linux would be about This works fine for most individual workstations. Depending on your intended use of the system.

When you separate a directory onto its own partition. Size of File Systems It is hard to say exactly how much space you'll need for various Linux file systems. System directories that are used for a lot of temporary data are also good candidates for separate file systems. This directory is sometimes put in its own small partition to guarantee it stays located at the beginning of a disk drive.

This is mostly a historical requirement for old boot hardware that could only read a limited area of the disk and is usually not an issue today. On a system with many users such as a server. The important issue for installation is how. XFS SGI's journaling file system You may choose any file system available in your distribution's installation program. It only stores files required for booting the kernel and associated files so it doesn't require much space.

Of course it is more work to set up separate partitions. Users will no longer be able to create new files. Windows boot code. On a Windows machine. That program. If you install the boot code into the MBR. The more optional software you add. Both do basically the same job: I would recommend you mount any Windows file system read-only so that files are not accidentally altered.

Some file systems can be mounted readwrite. Sharing File Systems If you plan to dual-boot your system with Windows or another distribution of Linux. I would not recommend this option. Most distributions of Linux come with a choice of boot loaders: Boot Loaders What we refer to as "booting" a computer derived from the word "bootstrap" as in.

Both can install themselves in the MBR.

The hardware knows how to load a small program from a known location and execute it. When the boot process starts. Windows partitions can be mounted and read by Linux.

If you install the boot loader to the first sector of the root drive. On a Linux machine. If you split the entire file system across multiple partitions. How big you make the other partitions especially a directory for users' home directories is mainly a factor of how much disk space you have available.

Windows code is notorious for "not playing well with others. The Linux boot loader program loads the kernel. If you plan to dual-boot your Linux system with Windows.

I had to reinstall both Windows and Linux. You should always make the boot floppy. A boot floppy allows you modify kernel parameters and location in the event a "normal boot" is not working because of a failure. Because I hadn't made a boot floppy this was a test system. But the default behavior is to boot the kernel on your hard drive just like a boot loader. Boot Floppy During the Linux installation process of most distributions.

This is a floppy disk that can be used to boot Linux in the case of a system crash or other failure that damages the boot sector of your hard drive. You may never use it. If you are installing a multiboot system. The floppy disk contains somewhat different information in this case.

Windows will boot. When you want to boot Linux. This removes the need to install a boot loader on your hard drive. This is by far the safest way to configure a dual-boot system. Don't let this happen to a system you care about! You can also use a boot floppy to boot Linux instead of a floppy with a boot loader installed. Everything was working fine until one day I powered up the system and got the message "Lilo timestamp mismatch" and then nothing.

If you are installing a single distribution on a system by itself. A boot floppy is a cheap insurance policy. Get Linux Once you have your hardware ready and have decided which distribution you want to run. Even if you don't know anybody who already has a copy. Approximate cost of some popular Linux distributions. While there is no license fee for the software. This is also true for the GNU utilities that go along with the Linux kernel to make up a typical Linux distribution.

Should you ever need to reinstall your Linux machine. Because the GPL allows it to be redistributed free of charge. There are many ways you can obtain Linux installation media or images. The blessing is that for nearly any type of machine with any limitation you can imagine.

CDs are easy to download. The curse is that there are so many options. That is both a blessing and a curse. The disadvantage of CDs is you generally have to download them. Talk to your systems administrator. Unless others at your company or school are experienced in such activities. Download If you are installing Linux in an environment with existing Linux machines such as a medium-tolarge company or a university. Downloading installable images involves copying standard ISO install images and writing them onto a CD or local hard disk.

You might be able to copy install images from another machine via any number of network utilities as long as you have a network card in your computer. Linux is available for download in many places. This is truly only an option if you have a high-speed connection to the internet.

At some point.

If you have a connection to the internet. The web sites I have found most useful are: I would highly recommend downloading an inexpensive distribution. Unless your PC is very old. Install Linux As I mentioned at the beginning of this chapter. Get the Documentation for Your Distribution The first thing you should do is get installation instructions for your Linux distribution.

Although they may do it differently. The names and locations of these files may vary. You may also find installation notes on the web sites of the various distribution sponsors. If it is not. Partition Disks. Fedora's Hardware Browser hwbrowser or Mandrake's Harddrake tool. If you install on a laptop when a removable floppy drive is not present.

Mandrake's Disk Drake tool creates extended partitions as necessary without asking you. Debian and Slackware still rely on cfdisk although a. Most distribution providers have created their own disk partitioning tools and no longer use fdisk and cfdisk. These special files are discussed in more detail in Chapter I cannot stress strongly enough how important it is that you make a backup copy of all data on the system that you care about before you attempt to repartition a disk.

As we saw previously. Fedora's Disk Druid allows you to "force" a partition to be primary. Each of the hard drives that are divided into multiple partitions will also have device names for each partition. All distributions of Linux include fdisk and cfdisk. In case you've missed it thus far. If you create more than a couple of partitions it can quickly get confusing. This is your final warning.. Also remember that some disk partitioning tools don't show you the difference between primary and extended partitions.

As you create partitions and assign them to parts of your Linux file system. Some of the more "bare bones" distributions e.

Whatever partitioning tool you use. This will be the limit to how much you can shrink your Windows partition. Some Linux distributions e. Once you update the partition table. I would also recommend letting it do the bad-block check during the format it takes longer. Unless you know your disk is in good shape.

One such tool with a fine reputation for ease of use and reliability is Symantec's PartitionMagic. Windows XP provides no tools to shrink its NTFS file system it has some disk management tools but they can only expand a file system. This is not necessary if a partition was not changed and it had been formatted previously. Once you have determined the correct new size for your Windows partition. System Setup. Debian puts it in the "tools" directory.

Mandrake and TurboLinux provide it in the "dostools" directory. The details of this vary a bit between different versions of Windows.. If you are not sure. If your Windows system uses the FAT file system format. One alternative is to download one of a number of commercial partitioning tools.. However you choose to shrink an existing Windows partition.

Until you write the partition table to the disk. There is no "undo" if you overwrite a disk partition that contained data you wanted! The Boot Loader During the installation process. Some distributions allow you to specify a security setting that will install or configure security functions. In this way. After the disk partitions have been created.

When you set the time on Linux. After editing the configuration file. This file also contains all the information about the various operating systems and boot parameters. LILO is the standard boot loader for Linux. This can be a problem if you dual-boot with Windows. In the system setup part of installation. This is all part of the same process in most distributions. Fedora and SuSE.

When time is displayed by an application. GRUB provides more capability. In a more simple process like Debian. If you do choose to rewrite your MBR. Even though boot loaders can install themselves in such a way that they can still let you boot Windows.

But it is safer to only write boot loader code into the MBR if you do not plan to boot Windows anymore i. I would recommend that you write your boot loader to a floppy disk instead and leave your Windows boot code alone. GRUB includes a command shell called grub that can modify boot information and write the new boat loader out to disk.

During Linux installation. Boot loaders usually preserve the Windows boot information and create a boot loader that will list Windows as one of the boot options. Describe the function of a boot loader. What is a dual-boot system? Exercises 1.

What is the major difference between the ext2 and ext3 file systems? Find three Linux distributions not mentioned in this chapter and state why someone might choose each of them over the more popular distributions. What are the minimum disk space and memory required for a system to run Linux reasonably well? How many primary partitions can be created on a disk drive?

What is the minimum number of disk partitions required to run Linux? Projects 1. Obtain a distribution of Linux and install it you saw that one coming. Obtaining an Account Section 3. Setting Your Password: Listing the Contents of a Directory: Listing the Contents of a File: Special Characters Section 3. Shells Section 3.

Obtaining Online Help: Absolute and Relative Pathnames Section 3. Logging Out Section 3. Creating a Directory: Poetry in Motion: Exploring the File System Section 3.

Renaming a File: Logging In Section 3. Creating a File Section 3. Changing Groups: Counting Words in a File: Changing a File's Owner: Groups Section 3. Determining Your Terminal's Type: Editing a File: Electronic Mail: File Attributes Section 3. Deleting a File: Deleting a Directory: Copying a File: Changing a File's Permissions: Printing a File: Moving to a Directory: Listing Your Groups: Changing a Terminal's Characteristics: Changing a File's Group: Epilogue Section 3.

I'll show you how to log on and off a Linux system. I'll also introduce you to the mail system so that you can enter the world of computer networking. If you don't have access to a Linux system. If not. If you have installed your own Linux system. See page of Chapter It is extremely important to create your own account rather than simply using the root account. Obtaining an Account In order to login on a Linux system.

If you will be using someone else's Linux computer. The root account has full system privileges and if you use that account all the time. Other possible events that might occur when you log in are: A help system recognizes that you're a first-time user and asks you whether you'd like a guided tour of Linux. The "news of the day" messages are displayed to your screen.

Linux is case sensitive. Depending on how your system is set up.. You are usually allowed to press the Enter key for the default terminal setting.

Logging In In order to use a Linux system. Here's an example login: This is so that it can set special characters like the backspace and cursor movement keys to their correct values. Last login: Sun Feb 15 You are then presented with a graphical desktop similar to the examples in Chapter 2. On a system with a fully installed X Window System. Many Linux machines display a login box rather than a text prompt. When you enter your password.

You are first prompted for your username and then for your password. I'll show you later how to change the terminal type if necessary.. It's sometimes necessary to press the Enter key also known as the Return key a couple of times to make the system give you a login prompt. It lets you run programs. In this chapter the only shell facilities that I use are the abilities to run utilities and to save the output of a process to a file.

A shell executes all of the commands that you enter. Let's go ahead and run a few simple GNU utilities. The three most popular shells in Linux environments are: This book contains information on how to use all three shells. One reasonable question to ask is: Why would you write a program in a shell language rather than a language like C or Java?

The answer is that the shell languages are tailored to manipulating files and processes in the Linux system. A shell is a program that acts as a middleman between you and the Linux operating system.

The optional ss is the number of seconds. From now on. It's self-explanatory. Not all systems have exactly the same utilities installed. I'll write a small synopsis of its typical operation in the format shown in Figure I also implicitly mean that you should press the Enter key after the text.. Only a super-user may set the date.

People tend to use these descriptions interchangeably. If arguments are provided. One utility that every system has is called date. Please note that I do not list every different kind of option or present a particularly detailed descriptionthis is best left to the manual pages available on your Linux system. This tells the shell that you've entered the command and that you wish it to be executed.

To run a utility. Description of the date command.

The clear command. Another useful utility is clear. This enables commands to interact with the terminal easily and still use input from other places and write output to other places when necessary. Standard output. Linux can write to files. Standard error. By default. Standard input. When man displays help about a given utility. Linux systems have a utility called man short for "manual" which puts this information at your fingertips.

The first usage of man displays the manual entry associated with word. Library Functions 4. Special Files 5.

You may also want to look up an argument not described in this text. System Calls 3. The second usage of man displays a list of all the manual entries that contain keyword.

The man command. If no section number is specified. File Formats 6. They contain information about utilities. User Commands 2. Miscellaneous 8. Games System Administration and Privileged Commands 9. Kernel Interfaces not included in all distributions Sometimes For example.. CHMOD 2. Here's an example of man in action: Special Characters Some characters are interpreted specially when typed in a Linux terminal window. The default meaning of each option is shown in Figure Option Meaning erase Backspace one character.

The stty utility is discussed fully at the end of this chapter. These characters are sometimes called metacharacters. Hi Tim. To do this Some of these characters won't mean much to you until you read some more chapters of this book. If you instruct a utility to do the latter. Terminating a Process: Control-C Often when you run a program you wish to stop it before it's finished. Control-D means "end-of-input. I hope you get this piece of mail.. Although there are a few programs that are immune to this form of process termination.

The standard way to do this in Linux is to press the keyboard sequence Control-C. Control-D Many utilities may take their input from either a file or the keyboard. Option Meaning intr Terminate interrupt the foreground job with no core dump.

How about building a country one of these days? The mail utility is fully described later in this chapter. This is because it's quite easy for someone to set up a computer program that runs through all the words in a standard dictionary and tries them as your password. Note that you wouldn't normally be able to see the passwords. To set your password.

You are prompted for your old password and then twice for the new one since what you type isn't shown on the screen. Description of the passwd command. If you can become the administrator New UNIX password: Here's an example.

If you forget your password.

A password should generally be at least six letters long. Retype new UNIX password: GWKW passwd: Changing password for ables current UNIX password: Most systems then display a "login: In the next few sections I'll describe some more utilities that allow you to explore the directory hierarchy and manipulate files. Graphical desktops are discussed in more detail in Chapter You've now seen how you can log into a Linux system I'm done!

Fedora Core release 2 Tettnang Kernel 2. Logging Out If you are simply logged in on the Linux console i. If you are running a graphical desktop environment. The next few sections are a running commentary on the Linux utilities that I used to create a final version of one of my song's lyrics. One of my hobbies is to compose music. Action Utility I displayed my current working directory. Exploring the File System I decided that the best way to illustrate some common Linux utilities was to describe a session that used them in a natural fashion.

Script of upcoming examples. Action Utility I removed the "lyrics. To illustrate this utility. To display your shell's current working directory. When you log into a Linux system.

The login shell starts at the user's home directory. Description of the pwd command. Figure shows the absolute pathnames of the "A. Different files may have the same name.

Absolute pathnames. A pathname relative to the root directory is often termed an absolute or full pathname. Although these files have the same name. Figure shows a small hierarchy that contains a "ksh" process and three files called "myFile. A pathname is a sequence of directory names that lead you through the hierarchy from a starting directory to a target file. Current and parent directories.The idea that an operating system could be written in a high-level language was an unusual approach at that time.

In general. Sumitahha Das. Transportation and. While most people refer to a complete system as Linux. The above chapters and: Ubuntu is well known for its robustness and security. Sharing Resources Another operating system function that Linux provides is the sharing of limited resources among competing processes.