(pn)Part I

(pt)Sun Certified System Administrator for Solaris 8 Study Guide, Exam 310-011

(cn)Chapter 1

(ct)Understanding System Concepts

    (1)Certification Objectives

In order to truly understand any machine, you must first understand it's function. Next, it's parts. Then, you must understand how those parts work together in order to perform the machine's function.

In this chapter, we're going to touch on all three in very general terms. The rest of the book will go into very specific details, but first we need to define some common terms. This chapter will cover the basic terminology in system administration and the use of the man command. It's a starting point designed to give you the foundation which the rest of the book builds on.

    (1)Defining system administration terms

All of these terms are dealt with in great detail in later chapters of this book. Here, we want to introduce you to the basics of terminology that the role of a System Administrator will require you to understand.


Many SysAdmins are quick to point out that a "daemon" is not a "demon". While sometimes it may seem like it, your server is not possessed. (Some of your users, maybe, but not your server.) We define a daemon as a program which runs in the background to manage system functions. The word literally means "divinity". The poet William Butler Yeats had a fascination with the concept of daemons and their representation of the duality of existence. He described them as beings which represent the opposing sides of our nature. You can't know what good is with out evil's existence. How could you recognize a great piece of pie, unless you've had a not-so-great one? Actually, the term "daemon" is derived from Greek mythology. The ancient Greeks called a supernatural being which acted as an intermediary between the gods and man as a "daemon". This is a very accurate description of what a UNIX daemon does for you. Basically, a daemon is always there, waiting to be called upon to perform some action or service. There are daemons running on a system for every service the system is providing. However, don't get a daemon and a process confused.

A process is an instance of a running program. So, while a daemon is a process, a process doesn't have to be a daemon. You can see all the processes which are running on your system by using the ps command. The ps command can be used to display all of the processes at once. This can be one big list even on a little-used system. Naturally, with the use of command options, you can use the ps command to display just the information you're looking for. We'll cover the ps command in more detail in later chapters, but for now, let's take a look at some of the daemons which are running on your system right now.

Exercise 1.1 - Viewing the daemons on a system.

Let's first take a look at what is going on behind the scenes on our Solaris system. For this exercise, our system's hostname is "sol".

Step 1. Log on to the system

[luna: ra]$ telnet sol


Connected to sol.

Escape character is '^]'.

SunOS 5.8


password: **********

Last login: Tue Apr 3 19:12:13 from :0

Sun Microsystems Inc. SunOS 5.8

Welcome to Sol - This system will be down for 4 hours this Sunday for upgrades. Call ext. 3649 if you have any questions.

[sol: ra] $

Step 2 - See the processes.

Now, we've logged in to sol as the user "ra" and seen a message from the very conscientious System Administrator regarding a planned outage. Next, let's take a look at the processes, including the daemons, which are currently running on sol by using the ps command.

[sol: ra] $ ps -ef | more


root 0 0 0 Mar 20 ? 0:03 sched

root 196 1 0 Mar 20 ? 0:16 /usr/sbin/nscd

root 206 1 0 Mar 20 ? 0:00 /usr/lib/lpsched

root 177 1 0 Mar 20 ? 0:01 /usr/sbin/syslogd

root 268 1 0 Mar 20 console 0:00 /usr/lib/saf/ttymon -g -h -p cc9972-b console login: -T sun-color -d /dev/cons

root 158 1 0 Mar 20 ? 0:01 /usr/sbin/inetd -s

root 157 1 0 Mar 20 ? 0:00 /usr/lib/nfs/lockd

daemon 160 1 0 Mar 20 ? 0:00 /usr/lib/nfs/statd

root 186 1 0 Mar 20 ? 0:01 /usr/sbin/cron


We used the ps command with the "e" and "f" options. This displayed every process and displayed a full listing. Since the list would easily cover more than one screen, we piped ( | ) the display into the "more" command. This way we can see on screen at a time, by pressing the space bar, we see "more" of the display. We'll cover the ps command in more detail later. For now, let's go daemon hunting!

The output of the ps command includes the following line, which is highlighted above:

root 206 1 0 Mar 20 ? 0:00 /usr/lib/lpsched

This is one of the daemons running on the system named sol. It's the printer spooling daemon, lpsched. This daemon waits for print requests, then sends the print job to the requested printer. It's always running, waiting for a print job to come in.

Exam Watch: Remember that most daemons end with the letter "d". Most are started by initialization scripts at boot time, but that this is configurable. Daemons can be stopped or restarted as needed. You will often have to restart a daemon after making a configuration change to it's service. Another instance would be to fixed a stuck print queue, you might have to stop/start the print spooler daemon.


A shell is the interface between you and the kernel. It's the means by which you communicate commands. There are many, many different kinds of shells out there. We will be focusing on 3 of the most popular: Bourne, Korn and C-shell.

The Bourne shell was written by SR Bourne and can be found on nearly all UNIX systems. While it lacks some of the bells and whistles of others, it remains one of the most prevalent shells in UNIX. The shell is located at /bin/sh and uses a "$" at the user prompt. Shell scripts are most often written to be run by the Bourne shell because of it's excellent input/output control and expression matching features. However, many people felt it lacked strong interactivity features.

To answer this need, the fine pioneers at UC Berkley developed the C-shell. This shell, located at /bin/csh and using a "%' at the user prompt, provides features not found in Bourne, such as job control, command history and aliasing. It's designed to use command syntax which resembles C, the programming language used to write UNIX. However, many people feel that it lacks strong control of input and output.

In an effort to combine the best of both, David Korn developed the Korn shell. The Korn shell can be found at /bin/ksh and uses a "$" at the command prompt. The Korn shell is a subset of the Bourne shell, but adds features such as aliasing, history and the popular command-line editing.

These three shells are provided as part of the Solaris Operating Environment. We will cover them in more detail later in the book, but for now let's take a look at how we can try a new shell.

Exercise 1.2 - Changing your shell.

When you create a user, the default shell assigned to that user is the Bourne shell. Let's walk through the steps you can use as the sysadmin to change a user's shell. Once again, we'll be using a Solaris 8 system named "sol" as our example.

Step 1. Login to the system and find out what shell you are using.

[luna: ra]$ telnet sol


Connected to sol.

Escape character is '^]'.

SunOS 5.8


password: **********

Last login: Tue Apr 4 17:22:10 from :0

Sun Microsystems Inc. SunOS 5.8

Welcome to Sol - Thanks for your cooperation during our upgrade process. This system now has two additional CPU's, 4 more gigs of RAM and a new UPS. Call ext. 3649 if you have any questions.

[sol: ra] $ echo $SHELL


Here we see that we have logged in as the user named "ra". Using the echo command we can see that the SHELL variable is set to /bin/sh. This tells us that we are currently using the Bourne shell. Now, let's change it.

Step 2. Switch to the root account

[sol: ra] $ su -

password: **********

Sun Microsystems Inc. SunOS 5.8


[sol: root] #

Now, you are the superuser, or root, of sol. Notice how the command prompt has changed from the user prompt "$" to the root prompt "#".

Step 3 - Using the passwd -e command

Execute the command "passwd -e" to change the shell fro the user named ra.

[sol: root] # passwd -e ra

The current shell will be displayed and you will be prompted for the new shell.

Old shell:/bin/sh

New shell:/bin/csh

[sol: root] #

Now, the next time you log in as the user ra, you will be using the C-shell.

Randy: This is the end of the exercise? Thanks - Julie

Julie- Yes. - rrc

On the Job: By default, users can't use the "passwd -e" command to change their shells, only the root user can. A user can however use another shell by changing the SHELL variable. This can be done by editing their ".profile" file in their home directory or from the command-line.

S&S - Shells

How can I tell what shell I'm using?
Use the command "echo $SHELL" to see what your shell variable is set to.
How can I find out more about my shell's capabilities Use the man command. For example, "man csh" will give you a good overview of using the C-shell. 


      (2)file system

A file system is a collection of files and directories organized in a hierarchical structure. Think of it as an upside-down tree. At the top, is the root directory. It contains all of the system files and is the beginning of the file system. Under root, which is expressed as " / ", you will find all of the rest of the system's directories, subdirectories and files.

Many people confuse a mount point such as /tmp or /export/home with a file system. A mount point is the location of a partition on the hard drive which has been segregated from other partitions. Since that partition must be mounted in order to be used, it must be given a mount point. For example, by default, Solaris 8 will create a separate space on the hard drive for user's home directories. This is so that a user would not be able to use up all of the available hard disk space by filling up their home directory. That space is located within the Solaris file system at "/export/home". Even though we express the location as being directly under the "/" root directory, it is not limited to the space of the root directory.

UNIX refers to a file by it's location. The "hosts" file is often referred to as "/etc/hosts". This is a necessary function of a command-line operating system. For example if you wanted to use the "cp" command to copy a file named "badda-bing.employee.list" to your home directory, you would have to tell the cp command exactly where the file is located and exactly where you want it to go.

For example,

[sol: root] # cp /export/home/silvio/badda-bing.employee.list /export/home/tony

Because of this, it often seems like UNIX SysAdmins are speaking another language.

On the Job: This is an actual conversation I had with a co-worker recently:

Me: Hey, find /1st_floor -name "Scott"

co-worker: cd /1st_floor/breakroom; ls | grep coffee


The kernel is the very heart of the operating system. It communicates instructions to the hardware, it schedules and executes all of the system commands. It manages all of the daemons, devices, the system resources such as memory, swap space and file systems. When you are running a shell program, such as the Bourne shell, you are using that program to communicate with the kernel.

The kernel is loaded during the boot process and must be running in order for the system to operate. The kernel specific files can be found in the following directories:

/kernel - This directory contains all the common kernel components that are needed for booting the system.

/platform/<platform-name>/kernel - This directory contains the components which are needed for a specific type of platform. For example, on an Intel system, this directory would be, /platform/i86pc/kernel

/platform/<hardware-class-name>/kernel - This directory contains the kernel components specific to this hardware class.

/usr/kernel - This directory contains kernel components common to all platforms within a particular instruction set.

On the job - On occasion, you may have to reconfigure the parameters of a Solaris kernel in order to tweak it for optimal performance. The installation of a database application, for example. Make sure you have read the instructions carefully and tested the changes on a test system before you do it on a mission critical system! Without a bootable kernel, you don't have a bootable system, which could get you booted out the door.

      (2)operating system

An operating system is a set of programs which manage all system operations and provide a means of communication between the user and the resources available to that user. There are 3 main component s to an operating system. They are:
We've defined the first two in this chapter. We'll discuss hardware in later chapters.

Exam Watch - The definition of a shell and an operating system are similar. Both are used to communicate instructions, but remember that a shell is a component of an operating system.

Sun Microsystems refers to Solaris 8 as an Operating Environment. So, what's the difference between an operating environment and an operating system? Consider the analogy that both are like a shelter in which we live. An operating system provides us with the bare essentials. It's like a tent which contains food, a sleeping bag and a T-1 connection to the Internet. Okay, if we're talking bare essentials, we could probably get by without the sleeping bag. In contrast, an operating environment would be a house with running water, electricity, home entertainment system, walk-in meat locker, hot-tub, and so on. An operating environment includes all of the bells and whistles which are included to make running the system easier and more fun. Solaris 8 is designed from the ground up as a server operating environment. You won't find games, cute sound effects or 3-D wallpapers here included with the installation. It does include some very handy administrative applications and features. These include:

These are just some of the features of the Solaris 8 Operating Environment which make it an industry stand-out.

On the Job - Sun Microsystems recently announced they would be dropping the CDE and OpenWindows GUI's in favor of GNOME. There's also been talk of including KDE as well. While this might affect how users access their workstations, you shouldn't get bogged down trying to learn how to use one kind of GUI over another. You worth as a SysAdmin will be measured at the command-line, not among icons.

    (1)Define the effect of using various man command options when viewing online manual pages

Without a doubt, no matter how far your journey into Solaris takes you, the beacon that you can depend on is the man command.

The man command, short for "manual", is the way we access information about the commands and configuration files on our system. It's not a difficult command to learn or use.

The syntax of the man command is:

man < command_name>

Let's look at how we use it to get information on another helpful command, the ls command:

Exercise 1.3 - Using the man command

Step 1 - Log on to the system

[luna: ra]$ telnet sol


Connected to sol.

Escape character is '^]'.

SunOS 5.8


password: **********

Last login: Tue Apr 8 11:44:12 from :0

Sun Microsystems Inc. SunOS 5.8

Welcome to Sol - Don't forget to log out when you're done. Call ext. 3649 if you have any questions.

[sol: ra] %

Step 2 - Use the man command to get information about the ls command

[sol: ra] % man ls

Reformatting page. Please Wait... done

User Commands ls(1)


ls - list contents of directory


/usr/bin/ls [ -aAbcCdfFgilLmnopqrRstux1 ] [ file ... ]

/usr/xpg4/bin/ls [ -aAbcCdfFgilLmnopqrRstux1 ] [ file ... ]


For each file that is a directory, ls lists the contents of

the directory; for each file that is an ordinary file, ls

repeats its name and any other information requested. The

output is sorted alphabetically by default. When no argument

is given, the current directory is listed. When several

arguments are given, the arguments are first sorted

appropriately, but file arguments appear before directories

and their contents.



The output of the man command is shown one screen at a time, the excerpt above shows the contents of the first screen. As you will see on your system, the man command shows you a brief description of the command, it's syntax and them more detailed information on it's use. The man command will also display the revision history of the command and in most cases the author.

Man pages are marked with either nroff tags or SGML (Standard Generalized Markup Language. Both of these methods are used to mark a document with tags to describe how to read the text. For now, let's just say they are similar to HTML being used to tell a web-browser how to display a web page. That's why when you start the man command, it says "Reformatting page. Please Wait... done" before displaying the page. The command is reading the documents tags in order to display it on your screen correctly. The man pages are usually kept in /usr/share/man. The man pages using SGML tags are found in /usr/share/man/sman* and the the man pages using nroff tags are kept in /usr/share/man/man*. The directories are searched in the order specified in the /usr/share/man/man.cf file.

The man command also includes some handy options you can use.

-k - The keyword switch

You use the -k switch to find information using a keyword search. The syntax for using this option is:

man -k <keyword>

For example, say you wanted to find information on viewing documents in the pdf format. You would type:

man -k PDF

Then, the man command would display all of the commands that dealt with PDF documents. Actually, it's going to display all of the commands which have "PDF" in their man pages.

-M - The path command

You would use this option if you wanted the man command to search for a command in a directory not specified in the /usr/share/man/man.cf file. The syntax for using this option is:

man -M <path_name>

For example, let's say you've loaded an application which has installed it's man pages into a directory not specified by the MANPATH variable or in the /usr/share/man/man.cf file., but into the directory /opt/app/man. To view information on a command from the man pages in that directory you would type:

man -M /opt/app/man <command_name>

This would force the man command to look only in the named path for the man page on that command.

-a - The "all" option.

Using the -a option will show you all of the man pages which match the name specified.

The syntax is

man -a <command_name>

The man pages will be searched in the order they are specified in the MANPATH variable or as specified in the /usr/share/man/man.cf file. For example, if you type:

man -a passwd

You will be able to scroll through first the man page for the passwd command, then the man page for the passwd file.

-f - Searching for files

This option will give you a brief summary of man pages which fit the name of the file you specify. The syntax is:

man -f <file_name>

For example, let's say you wanted to see what man pages exist for the passwd command. You would type,

man -f passwd

And you would see,

passwd passwd (1) - change login password and password attributes

passwd passwd (4) - password file

This tells you there is not only a passwd command but a man page on the passwd configuration file as well.

-s - The section search.

Now that we know there's more than one man page on passwd, how do we display the one we want? Commands sometimes have more than one version of a man page. These different versions are separated into sections. As we've seen, there are two versions of a man page for "passwd". By default, the man command displays the man page on the passwd command, not the man page on the /etc/passwd configuration file. The -s option allows us to specify a section of the available man pages for the specified command. For example,

man -s 4 passwd

This will display the man page which deals with the passwd file, not the command. We saw that the passwd file was in the (4) section of the manual when we used the -f option.

    (6)From the Classroom - UNIX isn't always UNIX
I have had the opportunity to work with a wide variety of different types of UNIX OS's in my career. The wide variety of UNIX flavors out there can be confusing, but they all share many similarities. I often hear fellow UNIX SysAdmins use the phrase "UNIX is UNIX", meaning that if you know one kind, you know them all. In some ways, that can be considered true, but for the most part, it's not. Every different brand of UNIX has it's own unique way of doing things. Solaris is no different. To prepare for these exams, make sure you use the man command on a Solaris system often. Even on simple, often-used commands. A switch or option which does one thing on one kind of UNIX may not do the same thing on another. The man pages are like the hidden history of UNIX. Many of them are virtually the same as they were when they were first added to a UNIX server. However, they will be updated to reflect any changes and will pertain to the version of UNIX on which they've been installed. By browsing through man pages on a Solaris system, you'll be able to see all of the available options for the commands on that system.
              (6)Certification Summary
In this chapter, we've covered the basic terminology you'll need to get started with the rest of the book. It's important that you have a complete understand of them before moving on to the next chapter. We've also covered one of the most helpful tools you'll ever need in your career as a SysAdmin, the man command. The man command is one of the tools which you should use on a regular basis to prepare for these exams.
              (6)Two-Minute Drill
Now let's go over the information this chapter covered.

        (3)Defining system administration terms

daemons - A daemon is a process which waits and listens for a request. The lpsched daemon waits for prints requests and sends them to the correct printer.

shell - The shell is the program used to communicate your commands, or the commands of an application or script to the kernel. There are 3 basic shells which are installed with Solaris 8: Bourne, Korn and C-shell.

file system - A file system is a collection of files and directories organized in a hierarchical structure.

kernel - A kernel is the master program which communicates the instructions of system applications to the system hardware. It also manages all devices, memory and processes.

operating system - The operating system is a set of programs which governs all operations and acts as a means for the user to communicate instructions to system resources.

        (3)Define the effect of using various man command options when viewing online manual pages

The man command provides several options to allow for specialized searching and displaying of the online manuals provided with Solaris.

Remember the available switches for the man command:

-k switch is for searching for keywords.

-M switch allows you specify a different path to a man page

-a switch allos you to view all of the available pages on a command

-f allows you to search and view brief summaries

-s allows you to view specified sections of available man pages for a command.

              (6)Self Test
The following questions will test your knowledge of the material presented in this chapter.

        (3)Defining system administration terms

1. You've run the command "ps -ef ". Which of the following is an example of a daemon?

A. /etc/hosts

B. /usr/dt/bin/dtscreen -mode pyro

C. /sbin/sh

D. /usr/lib/nfs/lockd

The correct answer is D, /usr/lib/nfs/lockd. This is one of the daemons which is used to provide NFS service. Daemons are often recognized by having the letter "d" at the end.

Answer A is incorrect as this is the host file on the system, which you probably wouldn't see if you ran the ps -ef command. Answer B indicates that the screen saver is running on the system and it's that really cool fireworks one. Answer C indicates that the Bourne shell is running.

2. A new user logs into a system an sees a "$" at the command prompt. What shell is this user using?

A. The Money Shell

B. The C-shell

C The Korn shell

D. The Bourne shell

The correct answer is either C or D. While the user is new, the default system shell can be whatever the SysAdmin set it to be when the user account was created. Out of the box, the Bourne shell is the default system shell.

Answer B is incorrect since the C-shell uses the "%" at the user prompt. Answer A is incorrect since, as of right now, there is no UNIX shell called the Money Shell.

3. What features does the Korn shell have that the Bourne shell doesn't?

A. Command-line editing

B. Faster processing of shell script

C The ability to flood the coolant chamber with tachyon particles thereby avoiding a warp core breach.

D. spelling correction

The correct answer is A. The Korn shell allows you to use editing commands such as those in the VI editor to change commands from the command-line.

Answer B is incorrect since Korn is a variation of the Bourne shell and has no effect on the speed of a scripts execution. Answer C is incorrect since it is the dilithium matrix which regulates the flow of energy from the warp core, through the plasma conduits to the coils in the warp nacelles not the Korn shell or tachyon particles.


4. Where did the C-shell get it's name?

A. It's short for "Complete-shell"

B. It's short for "Complicated-shell"

C. It's syntax is based on the C programming language

D. It doesn't mean anything.

Answer C is correct. The wizards at Berkley wanted a shell which would work like programming in C, so they made one.

Answers B and A are incorrect. Also, the C-shell is neither complete or complicated. Answer D is also incorrect.

5. What is the correct way to for a user to change their shell of the choices below?

A. Using the "passwd -shell <username>" command

B. Using the "passwd -e <username>" command

C A user can't change their shell

D. By changing the SHELL variable

Answer D is correct. Answer A is incorrect since there is no "-shell " option with the password command and a user won't have access to the passwd command. Same for Answer B, while there is a "-e" option, only the root user has access to the passwd command. Answer C is also incorrect.

6. What is the correct way to change a user's shell using the root account of the choices below?

A. Using the "passwd -shell" command

B. Using the "passwd -a" command

C A user can't change their shell

D. By changing the SHELL variable

Again, Answer D is correct. The root user has the ability to use the passwd command, but using "passwd -e <username>" is not one of the choices. Make sure you read each choice carefully on the actual tests before choosing an answer.

7. Which of the following is an example of a file's name?

A. /etc/default

B. /etc/hosts

C. hosts

D. /usr/man/man.cf

Answer B is the correct answer. It describes the complete pathname of a file, which is how UNIX names files. Answer A describes the location of a directory. Answer C could be a directory or a file name. Answer D could also be correct, if you moved or copied the man.cf file to this location, but the default location of the man.cf file is /usr.share/man/man.cf.

8. Which statement is true in regards to a kernel?

A. Once Solaris is installed, it's not required.

B. It's a good idea to delete it occasionally to make sure it doesn't get too big.

C. It is loaded during the booting of the system

D. It gets it's name since, like a military officer, it's in charge of everything.

Answer C is correct. Answers A and B are incorrect since the running of the kernel is what keeps the system running. Answer D is incorrect since the name "kernel" doesn't have anything to do with the military rank of "Colonel". Besides, everybody knows it's the Sergeants that really run things.

9. An operating system is best defined by which statement?

A. The complete package of files and applications which are included in the default installation of Solaris 8.

B. A collection of programs which manage all resources and provides the user with a means of communication with the system.

C Anything under 16, hit. Anything 16 or higher, stay.

D. A collection of files and directories.

The best answer is B. Answer A is describing an Operating Environment. Answer C is describing a system for winning at Blackjack. Answer D is describing the definition of a file system.

    (3)Define the effect of using various man command options when viewing online manual pages

1. The man command can be used to search for specific keywords. Which command would search for the keyword "login"?

A. man login

B. man -a login

C man -k login

D. man -s login

The correct answer is Answer C. this will display the man pages which have the keyword "login" in their description. Answer A will display the man page for login. Answer B is incorrect since the -a option will display all pages on login. Answer d is incorrect since the -s option is used to display sections.

2. The man command can be used to display all the available man pages on a command? Which command will display all of the man pages on the name passwd?

A. man -all passwd

B. man | grep passwd

C man -a passwrd

D. man -a passwd

Answer D is correct. This command will display all of the man page manuals which cover the passwd command, one after another.

Answer A is incorrect since there is no "-all" option. Answer B is incorrect since this doesn't follow the man command syntax. Answer C is incorrect since "passwd" is misspelled.

3. The man command can be used to display specific sections of information of a man page? Given the following output of the command: man -f shutdown,

shutdown shutdown (1b) - close down the system at a given time

shutdown shutdown (1m) - shut down system, change system state

shutdown shutdown (3socket) - shut down part of a full-duplex connection

shutdown shutdown (3xnet) - shut down socket send and receive operations

Which command will display the section of a man page which relates to shutting down the system at a given time?

A. man -s 1b

B. man -s 1b shutdown

C. man shutdown

D. man shutdown -s 1b

Exercise 1.4 - Using the man command to find a command name.

Solaris has a way or three to do just about anything. But what if you are trying to do something and don't know what command to use? For example, how would you find out what command to use to display the name of the system you're logged into? Let's take a look at a way to use the man command to help you find the command you need.

Step 1. Use the man command to search for a keyword.

# man -k name

Did it show you the command you're looking for? Possibly, but it's 3 or 4 screens of commands. How can we narrow our search? We can't use more than one keyword. Let's try another keyword. Since we're trying to determine the host's name or hostname, let's try using that as a keyword.

Step 2 . Narrowing the search

# man -k hostname

Is that a more manageable list? It's considerably smaller than the first one.

check-hostname check-hostname (1m) - check if sendmail can determine the system's fully-qualified host name

ethers ethers (4) - Ethernet address to hostname database or domain

gethostname gethostname (3c) - get or set name of current host

gethostname gethostname (3xnet) - get name of current host

hostname hostname (1) - set or print name of current host system

sethostname gethostname (3c) - get or set name of current host

And, we can see that one of the choices is a command called "hostname". What were the odds? Now let's see how the hostname command works before we run it.

Step 3. Investigating a command

# man hostname

We can see from the output of the command that just by typing the command "hostname", we will see the name of the system displayed. It's a good thing we checked it out first, since the hostname command can also be used to change the hostname of the system.

This is an example of using the man command to help jog your memory or to research your options among all the available commands on a system. Naturally, it's not likely that you'd have root access to a system and not know it's hostname or how to find it. This was just a simple exercise to demonstrate the use of the keyword search capabilities of the man command.