cat - this types out a file onto the screen.  should be used on text files.
      only use it with binary files to make a user mad [explained later]
      ex:
      $ cat note.txt
      This is a sample text file!
      $

cd - change directory .  You do it like this: cd /dir/dir1/dir2/dirn.
     the dir1/etc.... describes the directory name.  Say I want to get
     to the root directory.
     ex:
     $ cd /
     *ok, I'm there.*
     $ ls
     bin
     sys
     etc
     temp
     work
     usr
 all of the above are directories, lets say.
     $ cd /usr
     $ ls
     sirhack
     datawiz
     prophet
     src
     violence
     par
     phiber
     scythian
     $ cd /usr/sirhack
     $ ls
     hithere
     runme
     note.text
     src
     $
ok, now, you do not have to enter the full dir name.  if you are in
a directory, and want to get into one that is right there [say "src"], you
can type "cd src" [no "/"].  Instead of typing "cd /usr/sirhack/src" from the
sirhack dir, you can type "cd src"

cp - this copies a file. syntax for it is "cp fromfile tofile"
     $ cp runme runme2
     $ ls
     hithere
     runme
     note.text
     src
     runme2
Full pathnames can be included, as to copy it to another directory.
     $ cp runme /usr/datwiz/runme

mv - this renames a file. syntax "mv oldname newname"
     $ mv runme2 runit
     $ ls
     hithere
     runme
     note.text
     src
     runit
    files can be renamed into other directories.
     $ mv runit /usr/datwiz/run
     $ ls
     hithere
     runme
     note.text
     src
     $ ls /usr/datwiz
     runme
     run

pwd - gives current directory
     $ pwd
     /usr/sirhack
     $ cd src
     $ pwd
     /usr/sirhack/src
     $ cd ..
     $ pwd
     /usr/sirhack
     [ the ".." means use the name one directory back. ]
     $ cd ../datwiz
       [translates to cd /usr/datwiz]
     $ pwd
     /usr/datwiz
     $ cd $home
     [goto home dir]
     $ pwd
     /usr/sirhack

rm - delete a file.  syntax "rm filename" or "rm -r directory name"
     $ rm note.text
     $ ls
     hithere
     runme
     src
     $

write - chat with another user.  Well, "write" to another user.
syntax: "write username"
    $ write scythian
    scythian has been notified
    Hey Scy! What up??
    Message from scythian on tty001 at 17:32
    hey!
    me: So, hows life?
    scy: ok, I guess.
    me: gotta go finish this text file.
    scy: ok
    me: control-D [to exit program]
    $

who [w,who,whodo] - print who is online
    $ who
    login       term   logontime
    scythian +  tty001 17:20
    phiberO  +  tty002 15:50
    sirhack  +  tty003 17:21
    datawiz  -  tty004 11:20
    glitch   -  tty666 66:60
    $
    the "who" commands may vary in the information given.  a "+" means
    you can "write" to their terminal, a "-" means you cannot.

man - show a manual page entry.  syntax "man command name"  This is a help
      program.  If you wanted to know how to use... "who" you'd type
    $ man who
    WHO(1)   xxx......
      and it would tell you.

stty - set your terminal characteristics.  You WILL have to do "man stty"
     since each stty is different, it seems like.
     an example would be:
    $ stty -parenb
      to make the data params N,8,1.  A lot of Unixes operate at
      e,7,1 by default.

sz,rz - send and recieve via zmodem
rx,sx - send / recieve via xmodem
rb,sb - send via batch ymodem.   These 6 programs may or may not be on a unix.
umodem - send/recieve via umodem.
      $ sz filename
      ready to send...
      $ rz filename
      please send your file....
      ...etc..

ed - text editor.  Usage "ed filename"  to create a file that doesn't
     exist, just enter in "ed filename"
     some versions of ed will give you a prompt, such as "*" others will not
     $ ed newtext
     0
     * a
     This is line 1
     This is line 2
     [control-z]
     * 1 [to see line one]
     This is line 1
     * a [keep adding]
     This is line 3
     [control-z]
     *0a [add after line 0]
     This is THE first line
     [control-z]
     1,4l
     This is THE first line
     This is line 1
     This is line 2
     This is line 3
     * w
     71
     * q
     $
   The 71 is number of bytes written.
   a = append
   l = list
   # = print line number
   w - write
   l fname = load fname
   s fname = save to fname
   w = write to current file
   q = quit
mesg - turn write permissions on or off to your terminal (allow chat)
     format "mesg y" or "mesg n"
cc - the C compiler.  don't worry about this one right now.
chmod - change mode of a file.  Change the access in other words.
        syntax: "chmod mode filename"
        $ chmod a+r newtext
      Now everyone can read newtext.
      a = all
      r = read.  This will be explained further in the File System section.

chown - change the owner of a file.
       syntax: "chown owner filename"
       $ chown scythian newtext
       $
chgrp - change the group [explained later] of a file.
       syntax: "chgrp group file"
       $ chgrp root runme
       $
finger - print out basic info on an account.  Format: finger username
grep - search for patterns in a file.  syntax: "grep pattern file"
       $ grep 1 newtext
       This is Line 1
       $ grep THE newtext
       This is THE first line
       $ grep "THE line 1" newtext
       $

mail - This is a very useful utility.  Obviously, you already know what it
        is by its name.  There are several MAIL utilities, such as ELM, MUSH
        and MSH, but the basic "mail" program is called "mail".  The usage
        is:
        "mail username@address" or
        "mail username"
        or
        "mail"
        or "mail addr1!addr2!addr3!user"

        "mail username@address" - This is used to send mail to someone on
another system, which is usually another UNIX, but some DOS machines and some
VAX machines can recieve Unix Mail.  When you use "mail user@address" the
system you are on MUST have a "smart mailer" [known as smail], and must
have what we call system maps.  The smart mailer will find the "adress" part
of the command and expand it into the full pathname usually.  I could look
like this: mail phiber@optik
           then look like this to the computer:

           mail sys1!unisys!pacbell!sbell!sc1!att.com!sirhacksys!optik!phiber

Do not worry about it, I was merely explaining the principal of the thing.
Now, if there is no smart mailer online, you'll have to know the FULL path
name of the person you wish to mail to. For Instance, I want to mail to
.. phiber.  I'd do this if there were no smart mailer:

  $ mail sys!unisys!pacbell!sbell!sc1!att.com!sirhacksys!optik!phiber

    Hey Guy.  Whats up?  Well, gotta go.  Nice long message huh?
    [control-D]
  $
Then, when he got it, there would be about 20 lines of information, with
like a post mark from every system my message went thru, and the "from" line
would look like so:

From optik!sirhacksys!att.com!sc1!sbell!pacbell!unisys!sys!sirhack <Sir Hack>

        Now, for local mailing, just type in "mail username" where username
is the login you want to send mail to.  Then type in your message.  Then
end it with a control-D.

        To read YOUR mail, just type in mail.  IE:

        $ mail

        From scythian ............
        To sirhack ............
        Subject: Well....

        Arghhh!

        ?
 The dots represent omitted crap.  Each Mail program makes its own headings.
 That ? is a prompt.  At this prompt I can type:

        d - delete
        f username - forward to username
        w fname - write message to a file named fname
        s fname - save message with header into file
        q - quit / update mail
        x - quit, but don't change a thing
        m username - mail to username
        r - reply
        [enter] - read next message
        + - go forward one message
        - : go back one
        h - print out message headers that are in your mailbox.

There are others, to see them, you'd usually hit '?'.

--------

If you send mail to someone not on your system, you will have to wait longer
for a reply, since it is just as a letter.  A "postman" has to pick it up.
The system might call out, and use UUCP to transfer mail.  Usually, uucp
accounts are no good to one, unless you have uucp available to intercept mail.

ps - process.  This command allows you to see what you are actually doing
in memory.  Everytime you run a program, it gets assigned a Process Id number
(PID), for accounting purposes, and so it can be tracked in memory, as
well as shut down by you, or root.  usually, the first thing in a process
list given by "ps" is your shell name.  Say I was logged in under sirhack,
using the shell "csh" and running "watch scythian".  The watch program would
go into the background, meaning I'd still be able to do things while it was
running:
  $ ps
  PID  TTY  NAME
  122  001  ksh
  123  001  watch
  $
  That is a shortened PS.  That is the default listing [a brief one].
  The TTY column represents the "tty" [i/o device] that the process is being
  run from.  This is only useful really if you are using layers (don't worry)
  or more than one person is logged in with the same account name.  Now,
  "ps -f" would give a full process listing on yourself, so instead of
  seeing just plain ole "watch" you'd most likely see "watch scythian"

kill - kill a process.  This is used to terminate a program in memory obvio-
ously.  You can only kill processes you own [ones you started], unless you
are root, or your EUID is the same as the process you want to kill.