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.This was verifiedby creating a file showing the current user and group ownership.Next, the user bball changedto the users group, created a file, and verified that the created file has the new group s access.Finally, the user bball changed back to the original group, bball.As you can see, Linux offers you a great deal of flexibility in assigning file ownershipsand permissions.By using different combinations of directory and file ownership andpermissions, you can organize your system along lines of types of work, types of users, or typesof files.2 1 Red Hat Tools 329PART2 2VHour 22Red Hat ToolsIn this hour you ll learn how to use Red Hat Software s graphic system-administrationutilities.These easy-to-use programs are an efficient and handy way to configure andmaintain your system.You ll quickly learn why many Linux users prefer the Red Hat Linuxdistribution, and why several of the tools, such as the rpm command, or the Red Hat PackageManager, have become standard tools in the Linux system administrator s toolbox.This collection of Red Hat tools proves that Linux system management is becoming easier,and is catching up with the graphic system administration tools provided by commercialUNIX operating systems.In fact, if you have experience with any other systems, you may findthe Red Hat tools easier to use.Configuring Your System with theControl-PanelThis section discusses Otto Hammersmith s control-panel, through which you can accesseight system administrator tools.You must run the X Window System in order to use thecontrol-panel command, which you ll find under the /usr/bin directory.You ll also needto be logged in as the root operator to use all but one of control-panel s tools. 330 Hour 22To start the control-panel command, which uses files under the /usr/lib/rhs directory,type its name on the command line of an X11 terminal window.# control-panel &This command line starts the control-panel command.A vertical window with large buttonsappears.You can select different tools by moving your cursor over a button and pressing theleft mouse button.You also can change control-panel s window to display horizontallythrough its File menu (see Figure 22.1).Figure 22.1.The control-panelcommand is used to runand display Red Hatsystem administrationtools you can use as theroot operators to manageyour system.The fstool utility is also part of the control-panel command, but accord-ing to Red Hat Software, you should instead use the cabaret command(discussed later in this hour in the section Maintaining Your FilesystemTIME SAVERwith the cabaret Command ).The cabaret command also is availablethrough the setup utility.Some of the control-panel tools have built-in help.For information about the control-panelcommand, read its manual page.Creating and Maintaining Users with the usercfgCommandAs a system administrator, you may find yourself adding, deleting, or changing users and userinformation.If you don t want to use the adduser, passwd, chsh, chgrp, and chfn commands2 2 Red Hat Tools 331(discussed in Hour 20, Basic System Administration ), you can use the usercfg command(see Figure 22.2).This graphic tool presents a dialog box that enables you to implement the2 2following tasks:Edit user and group identification informationChange users login shellsChange users passwordsEdit users finger informationAdd or delete system usersFigure 22.2.The usercfg commandis a graphic interface toseveral command-linesystem administrationcommands.Run this command by clicking the usercfg button in the control-panel window, or by startinga terminal window and typing the following:# usercfgManaging System Services with the tksysvCommandThe tksysv command, by Donnie Barnes, is a run-level editor for Linux.While you don tneed to know all of the technical details about run-levels (you can find a description in the/etc/inittab file), you should know that this tool changes which system services are startedor stopped when you log in at the console, run the X Window System, or reboot your systeminto the single-user mode for system maintenance. 332 Hour 22The tksysv command presents a dialog box with a list of services on the left and five columnson the right, with each column representing a run level.You should definitely read the tksysv command s built-in help, accessedthrough the command s Help menu.Make sure you know what you redoing, because stopping services can have a drastic effect by potentiallyCAUTIONdisabling PPP connections, printing, or other system features you normallyneed.Start tksysv by clicking on the Runlevel Editor button in the control-panel window, or bystarting a terminal window and typing the following:# tksysvSetting the System Time with the timetoolCommandThe timetool command is used to set or reset your system s date and time.You also can setyour system to use a 24-hour clock.When you use timetool, you ll see a dialog box thatenables you to set the date and time.When you select a portion of the date or time, the portionis highlighted in red (if you re using a color monitor, of course).Change the value by clickingthe up or down arrow in the dialog box.This tool can be especially handy if you live in anarea using daylight savings time!To use the timetool command, select the Date and Time button from the control-panel, orstart the command from a terminal window by typing the following:# timetoolCreating Printers with the printtool CommandDetails about using the printtool command, used to install and set up your system sprinter(s), are in Hour 15, Preparing Documents. Configuring your Network Services with the netcfgCommandThe netcfg command is a convenient way for system administrators to easily configurenetworking services and devices (see Figure 22.3).It s not necessary to go into the details ofnetwork configuration, or to discuss using this command in great depth, but you shouldknow that this command installs networking services, such as Point-to-Point Protocol orSerial Line Interface Protocol connections.This is a handy tool you can use to set thehostname of your computer, add domain nameserver addresses for connecting to your2 2 Red Hat Tools 333Internet service provider, configure your system s loopback network device (necessary if youwant to run the Common Desktop Environment, discussed in Hour 8, Exploring Other2 2X11 Window Managers ), or add other network services for your users.Figure 22.3.The netcfg command isused to start, stop, add,delete, change, orotherwise configure arange of network devicesand services.Start the netcfg command through the control-panel, or by typing its name on the commandline:# netcfg &Creating a Symbolic Modem Link with the modemtoolCommandThe modemtool command creates a symbolic link, called /dev/modem, that points to aspecified serial port you select
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