Step-by-Step Installation
covered planning the installation of Ubuntu Linux: determining the requirements; performing an upgrade versus a clean installation; planning the layout of the hard disk; obtaining the files you need for the installation, including how to download and burn CD/DVD ISO images; and collecting information about the system. This chapter focuses on installing Ubuntu. Frequently the installation is quite simple, especially if you have done a good job of planning. Sometimes you may run into a problem or have a special circumstance; this chapter gives you tools to use in these cases.
Linux GUIs: X and GNOME
This chapter covers the Linux graphical user interface (GUI). It continues where Chapter 4 left off, going into more detail about the X Window System, the basis for the Linux GUI. It presents a brief history of GNOME and KDE and discusses some of the problems and benefits of having two major Linux desktop environments. The section on the Nautilus File Browser covers the View and Side panes, the control
bars, and the menubar. The final section explores some GNOME utilities, including the new Deskbar applet and Terminal, the GNOME terminal emulator.
Programming the Bourne Again Shell
introduced the shells and went into detail about the Bourne Again Shell. This chapter introduces additional Bourne Again Shell commands, builtins, and concepts that carry shell programming to a point where it can be useful. The first part of this chapter covers programming control structures, which are also known as control flow constructs. These structures allow you to write scripts that can loop over command line arguments, make decisions based on the value of a variable, setup menus, and more. The Bourne Again Shell uses the same constructs found in such high-level programming languages as C.
Although you may make use of shell programming as a system administrator, reading this chapter is not required to perform system administration tasks. Feel free to skip this chapter and come back to it when you will find it most useful.
System Administration: Core Concepts
1The job of a system administrator is to keep one or more systems in a useful and convenient state for users. On a Linux system, the administrator and user may both be you, with you and the computer being separated by only a few feet. Alternatively, the system administrator may be halfway around the world, supporting a network of systems, with you being one of thousands of users. On one hand, a system administrator can be one person who works part-time taking care of a system and perhaps is also a user of the system. On the other hand, several administrators can work together fulltime to keep many systems running.
exim4: Setting Up Mail Servers, Clients, and More
Sending and receiving email require three pieces of software. At each end, there is a client, called an MUA (mail user agent), which is a bridge between a user and the mail system. Common MUAs are mutt, Evolution, KMail, Thunderbird, and Outlook. When you send an email, the MUA hands it to an MTA (a mail transfer agent, such as exmi4 or sendmail), which transfers it to the destination server. At the destination, an MDA (a mail delivery agent, such as procmail) puts the mail in the recipient’s mailbox file. On Linux systems, the MUA on the receiving system either reads the mailbox file or retrieves mail from a remote MUA or MTA, such as an ISP’s SMTP (Simple Mail Transfer Protocol) server, using POP (Post Office Protocol) or IMAP (Internet Message Access Protocol).
Most Linux MUAs expect a local MTA such as exim4 to deliver outgoing email. On some systems, including those with a dialup connection to the Internet, the MTA sends email to an ISP’s mail server. Because most MTAs use SMTP to deliver email, they are often referred to as SMTP servers. By default, when you install exim4 on an Ubuntu system, exim4 uses its own builtin MDA to deliver email to the recipient’s mailbox file.
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Free PDF Ebook Praise for A Practical Guide to Ubuntu Linux
Free PDF Ebook Praise for A Practical Guide to Ubuntu Linux
