AL RI Part 1 MA TE Starting Out with Ubuntu Chapter 1: W hat Is Ubuntu? D Chapter 2: Playing with the LiveCD TE Chapter 3: Installing Ubuntu CO PY RI GH Chapter 4: Exploring the Desktop
What is Ubuntu? Secrets in This Chapter The Linux Kernel The GNU Utilities The Linux Desktop Environments Linux Distributions Ubuntu Linux Chapter 1
Part 1: Starting Out with Ubuntu O ne of the most confusing features of Linux is the concept of a distribution. Many novice Linux users get confused about what a distribution is and why there are so many of them. Before diving into the world of Ubuntu, it often helps to have an understanding of what Linux is and how it relates to Ubuntu. This will help you understand where Ubuntu came from, and you’ll have a better idea of which flavor of Ubuntu is right for you.
Chapter 1: What is Ubuntu? 5 Application Software Windows Management Software GNU System Utilities Linux kernel computer hardware Figure 1-1: The Linux system. Allowing anyone to change programming code in the kernel would result in complete chaos. Therefore, to simplify things, Linus acted as a central point for all improvement suggestions. It was ultimately Linus’s decision whether or not to incorporate suggested code in the kernel.
Part 1: Starting Out with Ubuntu Virtual Memory PhysicalMemory Swap Space The Kernel Figure 1-2: The Linux system memory usage. The memory locations are grouped into blocks called pages. The kernel locates each page of memory in either the physical memory or the swap space. It then maintains a table of the memory pages that indicates which pages are in physical memory and which pages are swapped out to disk.
Chapter 1: What is Ubuntu? 7 Figure 1-3: The Ubuntu System Monitor utility, showing the current memory usage. A shared memory page allows multiple processes to read and write to the same shared memory area. The kernel maintains and administers the shared memory areas, controlling which processes are allowed access to the shared area. The special ipcs command allows us to view the current shared memory pages on the system.
Part 1: Starting Out with Ubuntu Each shared memory segment has an owner that created the segment. Each segment also has a standard Linux permissions setting that sets the availability of the segment for other users. The key value is used to allow other users to gain access to the shared memory segment. Software Program Management The Linux operating system calls a running program a process.
Chapter 1: What is Ubuntu? 4759 4761 4814 4832 4920 5417 5425 5426 5437 5451 5632 5638 5642 6319 6321 6322 6343 6385 $ 9 ? Ss 0:00 /usr/sbin/gdm ? S 0:00 /usr/sbin/gdm ? Ss 0:00 /usr/sbin/atd ? Ss 0:00 /usr/sbin/cron tty1 Ss+ 0:00 /sbin/getty 38400 tty1 ? Sl 0:01 gnome-settings-daemon ? S 0:00 /usr/bin/pulseaudio --log-target=syslog ? S 0:00 /usr/lib/pulseaudio/pulse/gconf-helper ? S 0:00 /usr/lib/gvfs/gvfsd ? S 0:05 gnome-panel --sm-client-id default1 ? Sl 0:34 gnome-system-monitor ? S 0:00 /usr/lib/gnom
Part 1: Starting Out with Ubuntu The Linux system identifies hardware devices as special files, called device files. There are three classifications of device files: ♦♦ Character ♦♦ Block ♦♦ Network Character device files are for devices that can handle data only one character at a time. Most types of modems and terminals are created as character files. Block files are for devices that can handle data in large blocks at a time, such as disk drives.
Chapter 1: What is Ubuntu? 11 Table 1-1: Linux Filesystems Filesystem Description ext Linux Extended filesystem—the original Linux filesystem ext2 Second extended filesystem; provided advanced features over ext ext3 Third extended filesystem; supports journaling hpfs OS/2 high-performance filesystem jfs IBM’s journaling file system iso9660 ISO 9660 filesystem (CD-ROMs) minix MINIX filesystem msdos Microsoft FAT16 ncp Netware filesystem nfs Network filesystem ntfs Support for Microso
Part 1: Starting Out with Ubuntu The GNU organization (GNU stands for GNUs Not UNIX) developed a complete set of UNIX utilities but had no kernel system to run them on. These utilities were developed under a software philosophy called open-source software (OSS). The concept of OSS allows programmers to develop software and release it to the world with no licensing fees attached. Anyone can use the software, modify it, or incorporate it into his or her own system without having to pay a license fee.
Chapter 1: What is Ubuntu? 13 The bash shell was developed by the GNU project as a replacement for the standard UNIX shell, called the Bourne shell (after its creator, Stephen Bourne). The bash shell name is a play on this wording, referred to as the Bourne-again shell. Besides the bash shell there are several other popular shells that Ubuntu supports. Table 1-2 lists the more popular shells available in Ubuntu.
Part 1: Starting Out with Ubuntu The XFree86 software package is the older of the two, and for a long time it was the only X Windows package available for Linux. As its name implies, it’s a free, open-source version of the X Windows software. Recently, a new package called X.org has come onto the Linux scene. It too provides an open-source software implementation of the X Windows system.
Chapter 1: What is Ubuntu? 15 Figure 1-4 shows the standard GNOME desktop used in Ubuntu. Figure 1-4: The default GNOME desktop in Ubuntu 8.10. GNOME developers have produced a host of graphical applications that integrate with the GNOME desktop. These applications are shown in Table 1-3.
Part 1: Starting Out with Ubuntu As you can see, quite a few applications are available for the GNOME desktop. Some of these applications are included in Ubuntu by default, while others you have to install from the Ubuntu repository. Besides all of these applications, other Linux applications use the GNOME library to create Windows-based applications that run on the GNOME desktop.
Chapter 1: What is Ubuntu? 17 All of the panel features are similar to what you would find in Microsoft Windows. Besides the desktop features, the KDE project has produced a wide assortment of applications that run in the KDE environment. These applications are shown in Table 1-4.
Part 1: Starting Out with Ubuntu Table 1-5: Other Linux Graphical Desktops Desktop Description xfce A lightweight desktop that packages components separately so you can pick and choose which features you want to implement fluxbox A bare-bones desktop that doesn’t include a panel—only a pop-up menu to launch applications fvwm Supports some advanced desktop features such as virtual desktops and panels, but runs in low-memory environments fvwm95 Derived from fvwm, but made to look like a Windows
Chapter 1: What is Ubuntu? 19 Linux Distributions Now that you have seen the four main components required for a complete Linux system, you may be wondering how you are going to put them all together to make a Linux system. Fortunately, there are people who have already done that for us. A complete Linux system package is called a distribution. Many different Linux distributions are available to meet almost any computing requirement you have.
Part 1: Starting Out with Ubuntu These days, with home computers commonly having CD and DVD players built in, Linux distributions are released as either a CD set or a single DVD. This makes installing Linux much easier. However, beginners still often run into problems when they install one of the core Linux distributions. To cover just about any situation in which someone might want to use Linux, a single distribution has to include lots of application software.
Chapter 1: What is Ubuntu? 21 Many of the specialized Linux distributions (including Ubuntu) are based on the Debian Linux distribution. They use the same installation files as Debian but package only a small fraction of a full-blown Debian system. The Linux LiveCD A relatively new phenomenon in the Linux world is the bootable Linux CD distribution, which lets you see what a Linux system is like without actually installing it. Most modern PCs can boot from a CD instead of the standard hard drive.
Part 1: Starting Out with Ubuntu Some Linux LiveCDs, such as Puppy Linux, are designed with a minimum number of Linux system files and copy them directly into memory when the CD boots, which allows you to remove the CD from the computer as soon as Linux boots. Not only does it make your applications run much faster (because applications run faster from memory), but it frees up your CD tray for ripping audio CDs or playing video DVDs from the software included in Puppy Linux.
Chapter 1: What is Ubuntu? 23 The Ubuntu workstation distribution provides a complete home, school, and even office desktop environment, all in one package and all for free.
Part 1: Starting Out with Ubuntu Ubuntu Cousins The Ubuntu workstation distribution uses only the GNOME desktop environment. Consequently, other Ubuntu distributions have been developed to offer customers a choice (because that’s what Linux is all about).
