Running Linux, 5th Edition - Matthias Kalle Dalheimer [40]
We don't want to go into great detail here: the particulars of creating a new user account can be found in virtually every book on Unix system administration. We also talk about creating users in "Managing User Accounts" in Chapter 11. You should be able to find a tool that takes care of these details for you.
Keep in mind that to set or change the password on the new account, you use the passwd command. For example, to change the password for the user duck, issue the following command:
# passwd duck
This will prompt you to set or change the password for duck. If you execute the passwd command as root, it will not prompt you for the original password. In this way, if you have forgotten your old password but can still log in as root, you can reset it.
Getting Online Help
Linux provides online help in the form of manual pages. Throughout this book, we'll be directing you to look at the manual pages for particular commands to get more information. Manual pages describe programs and applications on the system in detail, and it's important for you to learn how to access this online documentation in case you get into a bind.
To get online help for a particular command, use the man command. For example, to get information on the passwd command, type the following command:
$ man passwd
This should present you with the manual page for passwd.
Usually, manual pages are provided as an optional package with most distributions, so they won't be available unless you have opted to install them. However, we very strongly advise you to install the manual pages. You will feel lost many times without them.
In addition, certain manual pages may be missing or incomplete on your system. It depends on how complete your distribution is and how up-to-date the manual pages are.
Linux manual pages also document system calls, library functions, configuration file formats, and kernel internals. In "Manual Pages" in Chapter 4, we describe their use in more detail.
Besides traditional manual pages, there are also so-called Info pages. These can be read with the text editor Emacs, the command info, or one of many graphical info readers available.
Many distributions also provide documentation in HTML format that you can read with any web browser, such as Konqueror, as well as with Emacs.
Finally, there are documentation files that are simply plain text. You can read these with any text editor or simply with the command more.
If you cannot find documentation for a certain command, you can also try running it with either the -h or -help option. Most commands then provide a brief summary of their usage.
Editing /etc/fstab
In order to ensure that all your Linux filesystems will be available when you reboot the system, you may need to edit the file /etc/fstab, which describes your filesystems. Many distributions automatically generate the /etc/fstab file for you during installation, so all may be well. However, if you have additional filesystems that were not used during the installation process, you may need to add them to /etc/fstab in order to make them available. Swap partitions should be included in /etc/fstab as well.
In order to access a filesystem, it must be mounted on your system. Mounting a filesystem associates that filesystem with a particular directory. For example, the root filesystem is mounted on /, the /usr filesystem on /usr, and so on. (If you did not create a separate filesystem for /usr, all files under /usr will be stored on the root filesystem.)
We don't want to smother you with technical details here, but it is important to understand how to make your filesystems available before exploring the system. For more details on mounting filesystems, see "Mounting Filesystems" in Chapter 10, or any book on Unix system administration.
The root filesystem is automatically mounted on / when you boot Linux. However, your other filesystems must be mounted individually. Usually, this is accomplished with the command:
# mount -av
in one of the system startup files