Inessential Unix by Rudolph Magyar 5/14/0

________________ Getting Around ----------------

>man topic

Provides complete but often confusing help about the topic "topic".

>cd some_directory

Changes the working directory to "some_directory".

>cd ..

Changes the working directory back one step of regression.  That is if you
are in "/home/superior/inferior", cd .. will take you to "/home/superior".

>cd

Takes you to your home directory.

>mkdir new_directory

Makes a directory entitles "new_directory".

>rmdir old_directory

Gets rid of "old_directory".

__________________ Working with files ------------------

>ls -la

Lists the files in the current directory.  The "a" tells the computer to
show system files, and the "l" controls the type of format.

>rm file.exe

Deletes the file "file.exe".

>rm -fr baneful_directory

Force deletes files in the directory "baneful_directory" and its
subdirectories.  "f" is for force, and "r" is for recursive.

>mv a.exe b.exe

Renames "a.exe" to "b.exe"

>cp file duplicate

Copies "file" to "duplicate".

>cat book.txt | more or >more book.txt

Displays the contents of the file "book.txt".  A single screen is presented
at a time.  The space bar advances to the next screen, and "q" quits.

>head book.txt and >tail book.txt

Shows the first (last) ten liness of "book.txt".

>chmod 755 my_file

Sets the permissions on the file called "my_file".  The first digit is you,
the second the local cluster (I think), and the final, the world.  7 means
full permision, 5 means read and execute.  Use "> ls -la" to check that
permissions are set properly...

___________________ Running executables -------------------

>executable.exe &

Runs an executable file.  The "&" means that the file is run in the back
ground.  You will continue to be able to enter commands at the prompt while
the file is running.

ctrl-C

Terminates the current process.

ctrl-Z

Puts the current process into the background

>bg

Starts running the last "ctrl-Z" process in the background.

>fg -4545

Puts process 4545 into the forground.

>ps

Shows the processes which you are running

>kill 111

Termionates the process with the number 111.

>kill -9 111

Force terminates the process with the number 111.

_____________ Printing -------------

> enscript -2GfTimes-Roman8 -C textfile.txt -opostscriptfile.ps

Makes a text file look a little more human.  Specifically, uses Times Roman
8 pt font, prints two columns, numbers the lines, adds a verbous header, and
saves the file as postscriptfile.ps.

> psnup -nup 4 postscript.ps dense postscript.ps

Puts four postscript pages onto one!

>lpr -Plocal print_me.txt

Prints the file called "print_me.txt" on the printer called "local".

>lpq -Plocal

Shows you which files are lined up for printing on the printer named
"local".

>lprm 123

Stops the printing jobbed numbered 123.

_______________________ Editting features -----------------------

>awk '{print $1, $3-$2}' data.txt > a.txt

Repackages data in file "data.txt".  Specifically, sends column one and the
sum of columns two and three to a file called "a.txt". ` >awk '{print $1,
$5}' data.txt | xgraph

Sends column one and five to be graphed by xgraph, an easy to use but not
too powerful graphing package.

>find . -name lostfile -print

Search current directory and subdirectories to find "lostfile".  It is
recommended that you not use find as it uses many system resources.

>locate lostfile

If root is assiduous and updates the database regularly, then, use this
instead of find.  It hogs less system resources up.

>grep -i cocacola *

Finds all files in the current directory which make reference to "cocacola".  
The $i$ makes the search NOT case sensative.


_________________________ Miscellaneous Useful Hints
--------------------------

Pushing the TAB key will print the previously entered line at the prompt.

For quick, user friendly editting, use PICO.

It is recommended that you use GNUPLOT for graphing and EMACS for editting.


We have installed the following useful packages:

 acroread - reader for PDF files

 secure shell - secure (preferred) remote login
 Here's an example of how to use this:
 > ssh kanga -l dft
 This will log you onto kanga and handle all the
 xhost-setenv business.
 > scp my_local.file dft@kanga:my_remote.file
 This copies "my_local.file" to the dft account on kanga,
 and it gives the file the new name "my_remote.file".
 This is much like ftp.
 > scp dft@kanga:my_remote.file .
 This puts "my_remote.file" on kanga to the current local
 directory.

 gnuplot - plotting program

 xmgr - another plotting program

 xfig - graphics tool

 xgraph - yet another graphing program

 enscript - utility which converts txt files to
 nice postscript formats.
 >enscript -2GfCourier7 text.txt -opostscript.ps
 This converts text.txt to postscript using a two column
 format with Courier7 font.  Notice that there is no space
 between "o" and "postscript.ps"

 xosview - CPU and system workload monitor