[GLLUG] Trying to Learn Linux yet again

[Ross S.]

Here is some information pertaining to the basics:

For books, I suggest Linux Administration: A
Beginner's Guide, Third Edition to get you started:
http://www.amazon.com/exec/obidos/ASIN/0072225629/qid=1050000785/sr=2-1/ref=sr_2_1/104-5360268-3007956

The following is taken from:
http://jgo.local.net/LinuxGuide/linux-commands.html
_____________________________________________________
Navigation

Navigating around the files and directories of your
hard drive could be a dreaded task for you, but it is
necessary knowledge. If you were a user of command
prompt interfaces such as MS-DOS, you'll have little
trouble adjusting. You'll only need to learn a few new
commands. If you're used to navigating using a
graphical file manager, I don't know how it'll be
like, but some concepts might require a little more
clarification. Or maybe it'll be easier for you. Who
knows? Everyone is different.
cd

As you might already have guessed, the cd command
changes directories. It's a very common navigation
command that you'll end up using, just like you might
have done in MS-DOS.

You must put a space between cd and the ".." or else
it won't work; Linux doesn't see the two dots as an
extension to the cd command, but rather a different
command altogether. It'll come to make sense if it
doesn't already.
ls

The ls letters stand for list. It basically works the
same way as the dir command in DOS. Only being a Unix
command, you can do more with it. :-)

Typing ls will give you a listing of all the files in
the current directory. If you're new to Linux, chances
are that the directories you are commonly in will be
empty, and after the ls command is run, you aren't
given any information and will just be returned to the
command prompt (the shell).

There are "hidden" files in Linux, too. Their file
names start with a dot, and doing a normal ls won't
show them in a directory. Many configuration files
start with a dot on their file names because they
would only get in the way of users who would like to
see more commonly used items. To view hidden files,
use the -a flag with the ls command, i.e. ls -a.

To view more information about the files in a
directory, use the -l flag with ls. It will show the
file permissions as well as the file size, which are
probably what are the most useful things to know about
files.

You might occasionally want to have a listing of all
the subdirectories, also. A simple -R flag will do, so
you could look upon ls -R as a rough equivalent of the
dir /s command in MS-DOS.

You can put flags together, so to view all the files
in a directory, show their permissions/size, and view
all the files that way through the subdirectories, you
could type ls -laR.
pwd

This command simply shows what directory you're in at
the moment. It stands for "Print Working Directory".
It's useful for scripting in case you might ever want
to refer to your current directory.
File Management

A lot of people, surprisingly for me, prefer to use
graphical file managers. Fortunately for me, I wasn't
spoiled like that and used commands in DOS. That made
it a bit easier for me to make the transition to
Linux. Most of the file management Linux gurus do is
through the command line, so if you learn to use the
commands, you can brag that you're a guru. Well,
almost.
cp

Copying works very much the same. The cp command can
be used just like the MS-DOS copy command, only
remember that directories are separated with slashes
(/) instead of backslashes (\). So a basic command
line is just cp filename1 filename2.

There are other extensions to the cp command. You can
use the -f command to force it. You can use the -p
command to preserve the permissions (and also who owns
the file, but I'm not sure).

You can move an entire directory to its new
destination. Let's say you want to copy a directory
(and all of its contents) from where you are to be
/home/jack/newdirectory/. You would type cp -rpf
olddirectory /home/jack/newdirectory. To issue this
command you would have to be in the directory where
the subdirectory "olddirectory" is actually located.
ln

A feature of linking files is available in Linux. It
works by "redirecting" a file to the actual file. It's
referred to as a symbolic link. Don't confuse this
term with the linking of programs, which is when
binary programs are connected with libraries that they
need to load in order to run.

The most simple way that I've ever used ln to create
symbolic links is ln -s existing_file link. Evidently
there's a hard link and a symbolic link; I've been
using a symbolic link all along. You can also use the
-f flag to force the command line to overwrite
anything that might have the symbolic link's file name
already.

To remove a symbolic link, simply type rm
symbolic_link. It won't remove the file that it's
linked to.
mv

The mv command can be used both to move files and to
rename them. The syntax is mv fileone filetwo, where
"fileone" is the original file name and "filetwo" will
be the new file name.

You can't move a directory that is located in one
partition to another, unfortunately. You can copy it,
though, using cp -rpf, and then remove it with rm -rf
later on. If you have only a single partition that
makes up your filesystem then you have very little to
worry about in this area.
rm

The rm command is used for removing files. You use it
just like the del or delete command in MS-DOS. Let's
say you want to remove a file called foobar in your
current directory. To do that, simply type rm foobar.
Note that there is no "Recycle Bin" like in Windows
95. So when you delete a file, it's gone for good.

To delete something in some other directory, use the
full path as the file name. For example, if you want
to delete a file called "windows" that's in the
directory /usr/local/src/, you would type rm
/usr/local/src/windows.

To remove an entire directory and its contents, type
rm -rf /directory where "/directory" is the path to
the directory that you want to delete. If you're
wondering, the "rf" stands for "recursive" and
"force". Be very careful with this command, as it can
wreak havoc easily if misused.
Editing

If you haven't figured out how important a text editor
is, you soon will. Graphical interfaces can't shield
you forever, and those utilities have their limits.
Besides, if you're reading this page, I'm inclined to
think that you want to be able to customize beyond the
capabilities of graphical utilities. You want to work
at the command prompt. I know you do.

The basic syntax to invoke these text editors is the
same. Type the name of the editor followed by the file
you want to edit, separated by a space in between.
Non-existent files will be blank. Blank files will be
blank as well.
emacs

To use GNU Emacs (or its counterpart, XEmacs), there
are really only two commands you need to know. Heck,
they're the only ones I know.

While you're editing a certain file with emacs or
xemacs, you can save it with the [Ctrl]-x [Ctrl]-s
keystrokes. Then to exit, type [Ctrl]-x [Ctrl]-c.
pico

The instructions for using pico are located on the
screen. You save the file by using the [Ctrl]-o
keystroke (for write-out) and exit with [Ctrl]-x.

As a permanent solution, you probably don't want to
use pico. It lacks real power. Since I am such a wuss,
however, I still have the bad habit of using pico once
in a while. Why? By pressing [Ctrl]­j I can get entire
paragraphs wrapped into a nice justified block. I
don't know how to do that with the other text editors.
vim

Most modern distributions include vim, derived from
the infamously arcane Unix editor, vi. (It stands for
vi Improved, as a matter of fact.)

Using vim is different in that there are several modes
in which you use it. To do actual editing of the
files, press [ESC] i (both separately). Then to save
it, press [ESC] : w. Escape, the colon, and "w" should
be keyed in one after the other. Finally, to quit,
type [ESC] : q. The same rules apply as in previous
vim commands.

You can use "w" and "q" at the same time to enable
yourself to write to the file and then quit right
afterwards. Just press [ESC] : w q.

If you don't have vim installed, try vi instead.
Monitoring Your System

An important part of system administration (especially
with your own system) is being able to know what's
going on.
tail

The program tail allows you to follow a file as it is
growing. Most often, I use it to follow
/var/log/messages. I do that by typing tail -f
/var/log/messages. Of course, you can use anything
else, including the other logs in /var/log/. Another
file you may want to keep an eye out for is
/var/log/secure.

If you want to leave that running all the time, I
recommend having some sort of terminal program in X,
logged in as root through su.

Another program you may want to look at is head. It
monitors the top of the file specified, instead of the
bottom.
top

This program shows a lot of stuff that goes on with
your system. In the program, you can type:

   1. M for memory usage information
   2. P for CPU information
   3. q to quit

Once you try it, you can see that top shows you the
memory usage, uptime, load average, CPU states, and
processes.
w

Typing w will tell you who is logged in. This can be
helpful if you're the only one who uses your computer
and you see someone logged in that's not supposed to
be.

Another alternative is who.
Shutting Down and Rebooting

To shut down your system, type shutdown -h now, which
tells the shutdown program to begin system halt
immediately. You can also tell it to halt the system
at a later time, I think, but you'll have to consult
the shutdown manual page for that (man shutdown).

To do a reboot, you can either type reboot or shutdown
-r. You can also use the famous Ctrl-Alt-Delete
combination to reboot, which you might already be
familiar with.

Shutting down and restarting properly (as described
above) will prevent your filesystem from being
damaged. Filesystem damage is the most obvious of the
consequences, but there are probably other things out
there that I don't know about. The point is, shut down
your system properly.

There are (rare!) cases in which the machine might
lock up entirely, and prevent you from being able to
access a command prompt. Only then will your last
resort be to do a forced reboot (just pressing the
restart button on the case).
________________________________

This should help some.  My suggestion is to get
familiar with man pages.  When I started a few years
ago I didnt know jack about linux.  And thanks to the
documentation that came with the programs I now feel
comfortable with the OS.  Also, learn about kernels,
and the structure of Linux. If you take it step by
step I am sure you will not have a problem learning it
with time. And dont forget to ask questions! :)

- Ross S.



--- martin <mdcasa@yahoo.com> wrote:
> Hello,
> 
> Ok I know that this is the Great Lansing user's
> group,
> but I don't have one here in Charlotte, NC.  I have
> been reading the listserv for a while and thought
> I'd
> pose this newb question.  I am really trying to get
> back into Linux.  A while back I made a conserted
> effort to learn, but got bogged down when I couldn't
> get my wireless nic to work under Mandrake 9.0.  So
> I
> just purchased Xandros off the web and waiting for
> it's arrival.  Any suggestions for where to go to
> study.  I have tried lot's of things, and I guess
> what
> I need is something hands on.  Heck, I'd even be
> willing to pay for it.  My local community college
> offers a class, but I have been told by several
> folks
> that the teachers aren't very good (they supposedly
> teach from the book and nothing else).  
> 
> At any rate I need some help.  I want to, once an
> for
> all, give Micro$oft the boot.
> 
> Thanks,
> 
> Martin
> 
> __________________________________________________
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=====
-=-=-=-=-=-=-=-=-=-=-=-=-
             Ross S.
http://www.fusion812.com

__________________________________________________
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