Clueless at the Prompt Issue 15

#### "Linux Gazette...making Linux just a little more fun!"

## CLUELESS at the Prompt: A Column for New Users

#### By Mike List, troll@net-link.net

Welcome to installment 2 of Clueless at the Prompt: a new column for new linux users. On advice from several respondents, I'm going to start using a new format for specifying commands:

        Typing them on a separate line
        separated from the text by a space

Hopefully, this will minimize any confusion by even the very inexperienced user as to what should be typed at the prompt.

Last time we explored some of the differences and similarities between linux and DOS/Windows, and I'm going to continue this time with some stuff you already know, but perhaps aren't fully aware of.

One respondent seemed to take exception to my DOS-linux comparison, reminding me of the features that make linux and unices(unix like systems) more powerful than DOS.

Fair enough, this is a new users column and I would like to make sure that I'm not assuming that everyone who reads this column can read my mind. Besides, if I endure the slings and arrows of outrageous gurus I can hopefully expand my knowledge base, which I can then use for future columns.

Still, the paradigm of SUPERDOS holds some water.It is, after all a command line operating system which supports a windowing system, which has all the capabilities of MS Windows plus a few features that make Windowslook pale.

When you installed linux from whatever distribution,most of the packages installed came as pre-compiled binaries that were for the most part usable as is. However, if you found any applications that didn't come with the distribution they'll probably need to be unpacked and installed or compiled or both.

You could use a utility like installpkg, pkgtool, or dopkg but unless the package is from the distribution, the utility will likely install it to the / (base ) directory, which is probably less than optimal.

Instead, use the midnight commander, which is a Norton Commander clone, to view the contents of the package. To do this find the file,( I don't have a CD-ROM so I'm not sure of the procedure there )locate the file, probably with .tgz or .tar.gz extension, and highlight the file, then hit enter. you will see the contents of the archive. Read the files called for instance, INSTALL, README, Readme.whatever, or any file whose name suggests that it has necessary information, for a clue as to where best to unpack it. For instance, X apps probably should be unpacked in the /usr/X11R6 directory. To unpack the archive:

         cd /thechosendirectory

then:

         tar -zxvf /wherethearchiveis/file

you will see a list of files as they unpack. When this process is done, you will be returned to your shell prompt. If you get any error messages they should be pretty self explanatory, for instance a message saying file not found means you didn't name the file correctly in the tar command, unexpected EOF means the file was very likely corrupted or download was incomplete, try to get the file one more time.

At your shell prompt type:

        ls

to see a list of files and directories that were untarred. then:

        less /anyfilenamelike INSTALL,README,Readme.*(*= unx, elf, lnx, etc)

It wouldn't hurt to check any license, or Copying files for info on propers to the authors. It also might be a good idea to print out the files if they are long or contain a lot of special instructions so you can read and reread them to minimize the possibility that you will have to recompile or reinstall. If you aren't familiar with linux printing you can just:

        cat /filename>/dev/lp0 (or lp1, or wherever your printer is located)

If you are in the directory that the file is in, you can skip the frontslash on the filename. If the files include a precompiled binary, you're done except to install if the documentation suggests a location other than where you unpacked and reboot or run ldconfig.

If you want to examine the contents of subdirectories of your current directory type:

        cd subdirectory   (leave off the / )

then,

        ls

or,

        ls subdirectory

If you cd to a subdirectory, you can return to the top level directory by typing:

        cd -

If you have chosen a source file distribution of the software, then you will need to read the file INSTALL very carefully to find what needs to be done. Typically you might run

        ./configure

then edit the Makefile with a text editor as described in the INSTALL or README files, then run:

        make

sometimes followed by an option like linux, unx, linux-elf as instructed in INSTALL.When it is done compiling, the time will vary according to the program, type:

        make install

sometimes followed by an option as above.

The above is only a general guide to steps usually needed to install software in linux, more detailed instructions will come with the archive. READ THEM CAREFULLY!or print out the files.

Back to the DOS-Linux comparisons. In DOS there is a method of concatenating several files together under a batch file, which could be run to execute a string of commands. Linux also has this capability but it is called scripting, basically if you ever used MSEdit to create a batch file, you've done it before, except that you must change permissions to make it executable. Type:

        chmod u+x filename

To make sure you have executable permission,type

        ls  in the directory the file is located, usually ~ , or /home/whoever you
        are

Look for an asterisk * after the filename which shows that it's an executable Then you can run the string of commands by simply typing the file name of the script you created.

Of course there's a lot more to writing scripts than this, but I'm just a GNUbee and some things take a little time. Ihave written a couple of very simple scripts to control the dialup to my ISP but they are very simple and rely on recursion rather than more correct scripting so they must be killed after they have done their jobs. An example is "on-n-on", a script I wrote to continue dialing until I can beat the busy signal on the remote modem. It is very simply:

        ppp-on
        sleep 30
        on-n-on

The script above is called up and dials every 30 seconds until a connection is reached, so when 30 seconds goes by without the modem dialling you will have a connection and can open a browser or E-mail. Before that you must quit by hitting Ctrl+C, however so that the script won't continue to use resources to do what it has already accomplished.

I am accepting suggestions as to how this could be done more correctly, but so far it works for me and I have given you an idea how simple scripts can be.

Thanks for all the input I got from readers and surprisingly from other authors, encouragement in the form of suggestions, none of them suggested that I go back to m******ft.

If I had some ideas about the kind of machines Linux is going on it would be helpful. I'm running a relatively old 486/66 with no CD-ROM so I installed from floppies, but most of the information here will be more about what can be done AFTER installation.

There is some discussion from from the Linux Users Support Team with regard to the most loved, most misunderstood linux institution, man-pages. Many people, myself included feel that they should be a little more user friendly, and some have suggested that they be replaced witha set of documents similar to howtos> Let me know what you think about man pages,how they could be improved, replaced supplemented, whatever,and I can have some info next time.

BTW, I made at least two errors in my DOS to Linux commands table, not very reassuring,but the DOS command for making a directory is:

        md

not

     mkdir

and file copy should have been:

        cp /filename /to

not

    cp /filename/filename /to

#### Next Time- Let me know what you would like to see in here and I'll try to oblige just e-mailtroll@net-link.net me and ask, otherwise I'll just write about what gave me trouble and how I got past it.

TTYL, Mike List

##### Copyright © 1997, Mike List
Published in Issue 15 of the Linux Gazette, March 1997