Mastering Red Hat Linux 9 [Electronic resources] نسخه متنی

Learning about GNOME Extras

GNOME comes with a number of bonus applications, accessible through the Main Menu button. They fall into several categories: Accessories, Internet, Preferences, Multimedia, and System Tools. This is not a comprehensive list of programs available through the Main Menu button; many are covered in the following three chapters. While most are based on the work of the GNOME project, a few third-party utilities are included in this section as well.

Accessories

GNOME includes several accessories that help you with simple computing tasks. They’re accessible through the Main Menu Ø Accessories submenu. As you can see in Chapter 17.

Figure 16.28: Accessories menus

Calculator

GNOME includes a simple scientific calculator, as shown in Figure 16.29. It responds to entries in a keyboard numeric keypad. You can copy the results to other GUI applications.

Figure 16.29: The GNOME Calculator

Character Map

The Character Map application, shown in Figure 16.30, allows you to work with a number of non-English languages that still use Roman-style alphabets. It provides an interface where you can include special letters and accented characters in your documents.

Figure 16.30: The GNOME Character Map

Dictionary

The GNOME dictionary provides access to the online dictionary server at dict.org. It uses TCP/IP port 2628, which is why there is no "www" or "http" in front of the URL. As long as you’re connected to the Internet, it’s easy to find the definitions that you need. An example is shown in Figure 16.31.

Figure 16.31: The GNOME Dictionary

File Roller

The GNOME File Roller is functionally similar to various Zip utilities associated with Microsoft Windows. In other words, it can view and extract the files from within a compressed archive. An example view of the files within a .tar.gz archive is shown in Figure 16.32.

Figure 16.32: The GNOME File Roller

Handheld PDA

When you select Main Menu Ø Accessories Ø Handheld PDA, GNOME opens the Pilot Link utility described earlier in this chapter.

Print Manager

When you run Main Menu Ø Accessories Ø Print Manager, GNOME opens a print monitor that checks for documents in your print queue. If you want to know more about the applicable documents, click Edit ‚ Preferences. If you haven’t configured a printer before, GNOME Print Manager starts the redhat-config-printer utility described in Chapter 25.

Text Editor

The gedit program is the standard GNOME GUI text editor. It’s surprisingly versatile for a Linux text editor, especially when compared to vi. Figure 16.33 illustrates a gedit view of the /etc/fstab configuration file.

Figure 16.33: gedit at work

The gedit program is also quite customizable. Click Edit Ø Preferences to open the Preferences menu. It allows you to customize the look and feel of text. For example, you can use it to modify fonts, colors, add line numbers, configure print settings, and add plugins.

VNC Viewer

AT&T’s Virtual Network Computing (VNC) provides a way to access remote graphical operating systems. You can start the VNC Client Viewer via Main Menu Ø Accessories Ø More Accessories Ø VNC Viewer. VNC Viewer works in conjunction with a remote VNC Server.

The VNC Viewer program opens a small VNC Server window, where you can enter the IP address and password of the remote server. As you can see in Figure 16.34, I’ve used it to open up a fully functional view of a remote Windows 2000 computer.

Figure 16.34: VNC Viewer accesses remote operating systems.

Documentation

Red Hat Linux now includes a Documentation menu, which supports easy access to any Red Hat Linux 9 documents that you might have installed. You can access this menu via Main Menu Ø Documentation as shown in Figure 16.35.

Figure 16.35: Documentation menu

When you select one of the documents shown, Red Hat Linux opens it in the default web browser.

Games

If you’ve installed any standard GNOME or KDE games packages on your system, you’ll be able to access them through Main Menu Ø Games. We do not cover the startup or operation of any Linux games. There are some who believe that games can give Microsoft Windows users more comfort during any transition to Linux.

Internet Utilities

GNOME includes a number of utilities and applications for communicating on the Internet. The difference between a utility and an application in this case is somewhat arbitrary; we’ll look at the Mozilla browser, the Ximian Evolution personal information manager, and the Gaim instant messaging (IM) utility in the Internet Applications section.

In this section, we’ll examine more basic programs, including instant messengers, chat programs, and other miscellaneous connection utilities. Internet Utilities are accessible when you click Main Menu Ø Internet; some are available through Main Menu Ø Internet Ø More Internet Applications, as shown in Chapter 17.

Figure 16.36: Internet menus

Video Conferencing

You can start GnomeMeeting by selecting Main Menu Ø Internet Ø Video Conferencing. Gnome- Meeting is a fully featured H.323-compliant videoconferencing application. In other words, you can use it to connect to other videoconferencing clients, such as Microsoft’s NetMeeting. It supports audio and video, which means you need a sound card and a “webcam” that is supported in Linux. The basic screen is shown in Figure 16.37.

Figure 16.37: GnomeMeeting

The first time you start GnomeMeeting, you should see a First Time Configuration Druid; otherwise, click Edit Ø Configuration Druid to get the screen shown in Figure 16.38. You’ll need your identifying information, your connection type (e.g., modem, ISDN, or DSL adapter), and sound and video device drivers. You can also use GnomeMeeting to connect your PC to the regular telephone network using a MicroTelco account from www.microtelco.com. You can modify your preferences later by clicking Edit Ø Preferences.

Figure 16.38: GnomeMeeting First Time Configuration Druid

exmh

The exmh program is an X window user interface for for Unix-style e-mail mail handlers (MH). It’s useful for searching through internal messages, as shown in Chapter 25, you’ll be able to reply or forward any messages that you receive.

Figure 16.39: exmh handles mail.

The first time you open exmh, it checks whether you have an MH account. If not, it goes through a wizard to set up your MH environment, and sets up a .mh_profile in your home directory.

Galeon

While the default Red Hat web browser is Mozilla, there’s an alternative GNOME browser known as Galeon. The first time you open this browser, you’re prompted to set it up using bookmarks from Netscape or Mozilla, toolbars, and proxy settings on your gateway (if any).

You can also integrate Galeon as the default client for normal (HTTP) web pages, secure (HTTPS) web pages, FTP sites, and GNOME help, and for browsing files in local directories.

As you can see in Figure 16.40, Galeon does not include Mozilla’s functions in the left-hand pane; some might suggest that provides a cleaner interface. You can edit your preferences with the Settings Ø Preferences command.

Figure 16.40: The GNOME Galeon browser

IRC

Linux includes an Internet Relay Chat (IRC) program, X-Chat, that allows access to many different chat servers, as you can see in Figure 16.41. Other groups may have their own IRC servers, which you can set up by clicking the New Server button.

Figure 16.41: X-Chat and IRC

Once you’ve configured X-Chat, select the chat server of your choice and click Connect. If the server is available, you’re taken to a chat window similar to what is shown in Figure 16.42.

Figure 16.42: Chatting on IRC

Pan

GNOME includes a graphical newsreader known as Pan. As shown in Figure 16.43, it allows you to read and post messages on different newsgroups.

Figure 16.43: Pan can read newsgroups.

When you start Pan for the first time, you’re prompted for basic login information, including your e-mail address, the SMTP server, and the name of the news server. If you’re using sendmail on the local computer, you can use localhost; otherwise, use the outgoing e-mail server for your ISP.

If you want to change the look of your posts, click Tools Ø Posting Profiles. If you want to change or add a news server, click Tools Ø News Servers.

Remote Desktop Connection

If you have a remote desktop server, you can connect to it with the Remote Desktop Connection utility, shown in Figure 16.44. It works with computers with VNC servers. The advantage of a remote desktop connection is that it takes you into a full-screen mode. Except for a small label at the top of the screen, your desktop environment appears identical to the remote computer.

Figure 16.44: Making a remote desktop connection

Sylpheed

Sylpheed is an e-mail client developed with the same basic tools as GNOME: GTK+ (GNOME Tool Kit). It’s developed in Japan so it reportedly includes a strong Japanese language interface. It’s a lightweight mail manager, unencumbered by any web browser. A configured version is shown in Figure 16.45.

Figure 16.45: The Sylpheed mail manager

Sylpheed is fairly easy to configure. You start with the Configuration menu, which offers a series of menu command options, described in Table 16.3.

Internet Applications

In this section, we’ll cover three basic applications commonly run by Linux users on the Internet. These are Red Hat default programs: the web browser, Mozilla; the Personal Information Manager, Evolution; and the Instant Messenger (IM) client, Gaim, which are accessible via Main Menu Ø Internet.

Mozilla

The default Red Hat web browser is Mozilla. It is a fully featured web browser, built on the code that Netscape re-released as open source in 1998. You can navigate between several features by clicking on the icons shown in the lower-left corner of the window (see Figure 16.46). From left to right, these icons are associated with a browser, mail and newsgroups reader, web page composer, address book, and IRC chat client.

Figure 16.46: Mozilla icons

Alternatively, there are control keys associated with each of these features, as described in Table 16.4.

The Mozilla Browser

The default Mozilla web browser has the same look and feel as Netscape, as shown in Figure 16.47. It includes commands associated with Netscape, such as the What’s Related sidebar.

Figure 16.47: The Mozilla web browser

You can customize various Mozilla settings. Click Edit Ø Preferences to open the Preferences window shown in Figure 16.48. The options should be familiar to Netscape users.

Figure 16.48: Setting Mozilla preferences

The Mozilla Mail and Newsgroup Reader

When you open the Mozilla Mail and Newsgroup reader for the first time, you’re prompted to set up an e-mail or newsgroup account. If you want to add additional accounts, click Edit Ø Mail And Newsgroups Account Settings. In the window that opens, click Add Account.

For an e-mail account, you need your name, e-mail address, incoming POP or IMAP e-mail servers, and your outgoing SMTP server. You should be able to get this information from the ISP associated with your e-mail address. More information on these mail protocols is available in Chapter 26.

Once configured, Mozilla includes hyperlinks for basic functions, as shown in Figure 16.49.

Figure 16.49: Mozilla and e-mail

The Mozilla Composer

The Mozilla Composer allows you to create and edit web pages. For example, the code shown in Figure 16.50 comes from the help files associated with the redhat-config-httpd utility. As you can see, you can review the web page in a normal view, with HTML tags, from the HTML source code, and preview how it will look in a browser.

Figure 16.50: The Mozilla Composer

The Mozilla Address Book

The Mozilla address book allows you to collect a variety of information for each of your contacts, as shown in Figure 16.51.

Figure 16.51: A Mozilla address book entry

The Mozilla Chat Client

Mozilla chat, also known as ChatZilla!, is a link-based program. When you start Mozilla chat, you should see the screen shown in Figure 16.52. You can click on one of the Available Networks, which are actually in blue in a ChatZilla screen.

Figure 16.52: ChatZilla!

For example, to access the undernet IRC network, click on its link in the ChatZilla! window. Once it logs you into the server, you’ll be able to join the chat room of your choice. In some cases, you’ll see a link in the opening messages, such as

/join #phoenix

If you know the room that you want, you can just type in the associated command; in this case, substitute the desired chat room for phoenix. If successful, you’ll see a room with users such as that shown in Figure 16.53.

Figure 16.53: Communicating with ChatZilla!

Evolution

While the name of the program on the GNOME desktop is Evolution Email, it is so much more. It serves as a personal information manager, similar to Microsoft Outlook.

When you first start Evolution, you’re prompted to configure your profile. Evolution can handle all types of standard e-mail, including POP, IMAP, and MH-style servers. It also requires that you identify your time zone, and it prompts you to import your address book and e-mail from other formats.

As you can see in Figure 16.54, the Evolution summary view lists the status of your local weather, e-mail, appointments, and upcoming tasks. One additional useful feature for Linux administrators is a list of the latest Red Hat errata.

Figure 16.54: Ximian Evolution

Instant Messenger

GNOME includes an instant messenger (IM) client, suitable for connections to a variety of servers, including those provided by America Online (AOL), Yahoo!, and the Microsoft Network (MSN). The official acronym is Gaim, which is short for a GNU version of some popular IM program (which I should not name). In reality, the acronym does not do Gaim justice, as unlike the proprietary IM programs, Gaim uses plug-ins, which are essentially program adapters, to connect to several different types of IM networks. The Gaim login screen is shown in Figure 16.55.

Figure 16.55: Gaim login screen

To access a specific network, you need to install one of the configured plug-ins. In Gaim, click Plugins to open the Gaim - Plugins window. In that window, click Load, which lists available plug-ins in the /usr/lib/gaim directory. Some of the more popular plug-ins are shown in Table 16.5.

For details on required login information, consult the IM provider of your choice. The Screen Name corresponds to your account; the Alias is what is typically seen in the IM chat area.

Preferences

Most of the utilities associated with the Main Menu Ø Preferences submenu were covered earlier in this chapter, in the discussion on the GNOME Control Center. This section deals with the utilities associated with the Main Menu Ø Preferences Ø More Preferences submenu. These menus are shown in Figure 16.56.

Figure 16.56: Preferences menus

CD Database

There are a series of CD Database (CDDB) servers that provide additional information about your favorite music CDs. When you open the CD Database Preferences window, you can configure access to these servers. Some are available through www.freedb.org; the home page for CDDB is www.gracenote.com.

Panel

The Panel Preferences window allows you to configure the behavior of the GNOME panel, as well as any drawers that you configure within the panel. A drawer is similar to a Main Menu button, where you can configure links to the applications and menus of your choice.

Sessions

The Sessions window allows you to configure the programs that start when you enter the GNOME desktop. It also allows you to configure the behavior when GNOME starts, and monitors currently loaded programs. As shown in Figure 16.57, the window contains three tabs, described in Table 16.6.

Figure 16.57: GNOME Sessions management

Multimedia

Several GNOME multimedia applications are available when you click Main Menu ‚ Sound & Video. As shown in Chapter 17.

Figure 16.58: Multimedia menus

Audio Player

The Audio Player is the X Multimedia System (XMMS). While the Media Player itself looks unimposing (see Figure 16.59), it allows you to set up a virtual recording studio where you can mix different sounds.

Figure 16.59: X Multimedia System

CD Player

The GNOME CD Player is an easy-to-use player for audio CDs. As shown in Figure 16.60, it has the standard buttons that allow you to play and move between CD tracks.

Figure 16.60: GNOME CD Player

If you click on the name of the song, you’ll be able to select the song of your choice from the CD tracklist. The two buttons to the left of the song name allow you to edit the track database and manage the preferences for the CD Player.

Sound Recorder

The Sound Recorder performs as advertised; it allows you to record sounds that come in through the sound card microphone port. You can also play any .wav file sounds that you’ve recorded. In addition, it includes a mixing function that lets you control the volume from multiple sources.

Volume Control

The gnome-volume-control utility allows you to control the volume to and from a number of sources, as shown in Figure 16.61.

Figure 16.61: GNOME Volume Control

Grip

Grip (GNOME rip) is a GNOME CD player and burner. It can take the tracks of your choice from CDs or downloads, and it allows you to configure the music of your choice for CD recording, in the desired order. As you can see in Figure 16.62, it includes several configuration tabs as well as standard CD functions at the bottom of the window. The tabs are briefly described in Table 16.7.

Figure 16.62: The Grip CD player and burner

Files are normally saved in .ogg format in the ~/ogg directory, and the .m3u format in a subdirectory associated with the name of the artist.

System Tools

There are a wide variety of system tools available. Many are redhat-config-* tools which are primarily covered in Chapter 19. Others are covered in this section. The System Tools menus are shown in Figure 16.63.

Figure 16.63: System Tools menus

X CD Writer

The X-CD-Roast tool shown in Figure 16.64 allows you to copy and write music and data CDs. Before you use X-CD-Roast, you should first configure it from its Main Menu by clicking Setup. This allows you to verify detection of your CDs, modify the location of recorded image files, and more.

Figure 16.64: X-CD-Roast

Disk Management

The User Mount Tool, shown in Figure 16.65, illustrates the current state of various Linux filesystems, based on /etc/fstab. You can use it to mount or format a filesystem such as /mnt/floppy.

Figure 16.65: The User Mount Tool

Floppy Formatter

The gfloppy tool allows you to format disks on an installed floppy drive. It allows you to select from installed floppy drives, specify data format and size, name the volume, and format in various modes.

Hardware Browser

The Hardware Browser illustrates detected devices on your computer, as shown in Figure 16.66. This browser is for information only; no configuration is possible in this window.

Figure 16.66: The Hardware Browser

Printing Notification Icon

When you select the Printing Notification Icon, you’re activating drag-and-drop printing.

Print Manager

The GNOME Print Manager allows you to control and manage printers and print jobs. If you don’t have any configured printers, it starts the redhat-config-printers utilty, which is covered in Chapter 25.

Red Hat Network

The Red Hat Network configuration tool, shown in Figure 16.67, sets defaults for your up2date connection to the Red Hat network management servers. It includes three tabs, as described in Table 16.8.

Figure 16.67: Red Hat Network Configuration

Red Hat Network Alert Icon

The Red Hat Network Alert Icon utility adds a circular icon to your taskbar. One alert icon should already be there by default. The icon you see may include one of the following:

A blue check mark indicates that the packages on your system are up to date.

A green pair of arrows tells you that your system is communicating with the Red Hat Network.

A red exclamation point lets you know that your system does not include the latest packages, according to the Red Hat Network.

System Monitor

The GNOME System Monitor allows you to monitor current processes, as well as CPU and swap partition usage. It’s a customizable front end to the top command. The System Monitor tab illustrating system loads is shown in Figure 16.68.

Figure 16.68: GNOME System Monitor

Terminal

GNOME Terminal is the standard command-line interface used on the GNOME desktop. With its black-on-white interface, it is easy to read; I’ve used it in most of the command-line based screenshots in this book.

traceroute

There are two system tools related to the traceroute command, which maps the path of your data from your computer to the destination. Figure 16.69 uses xtraceroute to illustrate the path of a connection between my computer in the United States to the website for Egypt Air.

Figure 16.69: Tracing a network route

CD Writer

The GNOME CD Writer is known as GnomeToaster, as shown in Figure 16.70. It allows you to configure audio and data CDs. It includes an extensive array of preferences, and supports “drag and drop” copying.

Figure 16.70: The GnomeToaster

Configuration Editor

GConf is in a sense a GNOME configurator for all the settings stored in users’ home directories. Microsoft Windows users may recognize the Registry-style interfaces shown in Figure 16.71, and revisions can be nearly as dangerous to your ability to run GNOME. However, it is an all-in-one interface that allows you to edit GNOME settings without opening every last GNOME application.

Figure 16.71: The Conf Editor

More information on the workings of GConf is available from developer.gnome.org/feature/ archive/gconf/gconfl.

lokkit

The lokkit utility helps you configure firewalls. At the command-line interface, lokkit is functionally similar to the redhat-config-firewall tool described in Chapter 19. However, from the Main Menu button, it starts a firewall wizard that guides you through the configuration process. One example is shown in Figure 16.72, which allows you to let people on other computers access your local web server.

Figure 16.72: lokkit helps you configure a firewall.

One weakness of the GUI version of lokkit is that it does not give you a chance to customize access through additional TCP/IP ports. For more information on firewalls, see Chapter 22.

x3270

The x3270 utility starts a terminal suitable for accessing IBM mainframe computers. It includes the function keys commonly associated with mainframe terminals.