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          UNIX Quick Reference - A partial list of useful commands
                             By Michael Walden

The following information has been collected over the years, starting in 1989.
This began when I started using various shell accounts to gain access to the
Internet.  I initially used shell accounts on an AT&T 3B1 (7300) Unix PC and
then Sun SPARC based systems.  Later, other system types followed.  So, not
all of the following will apply to your system.  There have been no updates
to cover the latest Linux specific commands.  I may add Linux commands in the

************ HELP
man        - VERY HANDY! I suggest you use this to get the help info & syntax
             on all of the other commands.  Syntax is man command [enter]
whatis     - Display a one-line summary about a keyword (whatis ls)
apropos    - Locate commands by keyword lookup
info       - GNU's hypertext system
help       - Display the shell's help

************ INTERNET / NETWORK
telnet     - User interface to a remote system
ftp        - File transfer program (binary, ascii, get)
lftp       - Sophisticated ftp program
ncftp      - Anonymous oriented file transfer program (lookup, !ls)
archie     - File locater (prog ____, set search sub, set search exact)
gopher     - Connect to gopher document server
lynx       - WWW text browser
irc        - Internet relay chat (irc.duq.edu)
rlogin     - Remote login
talk       - Talk to another user
finger     - Display information about users
whois      - TCP/IP internet user name directory service
ping       - Send ICMP ECHO_REQUEST packets to network hosts
uucp       - System to system copy
nslookup   - Query Internet domain name servers.
host       - look up host names using domain server
traceroute - Print the route packets take to network host

************ MAIL / NEWS
elm        - An interactive mail reader
mail       - Runs the mail program, lets you send mail to other users
tin        - An interactive news reader (rtin, cdtin, tind)
pine       - An interactive news AND mail reader (OLD)
alpine     - An interactive news AND mail reader (NEW)
slrn       - An easy to use NNTP based newsreader
mutt       - The Mutt Mail User Agent
rn,rrn     - Read news
trn,trrn   - Threaded read news program
newsgroups - A program to list unsubscribed newsgroups
uuencode   - Encode a binary file into text
uudecode   - Decode a text file into binary

************ FILE TRANSFER
kermit     - Kermit file transfer protocol
rz         - Receive a file using the zmodem file transfer protocol
sz         - Send a file using the zmodem file transfer protocol
sz -w 2048 - Send a file using zmodem with a 2048 byte window size (Faster)

************ FILE ENCRYPTION
pgp        - Pretty Good Privacy encryption system

compress   - Compress a file
uncompress - Uncompress a file
tar        - Create tape archives, and add or extract files
gzip       - GNU zip
gunzip     - GNU un-zip
gzexe      - Compress executables
zcmp       - Compressed file compare
zdiff      - Compressed file diff
zmore      - Compressed file more
zcat       - Compressed file cat
zgrep      - Compressed file grep
znew       - Recompress .z files to .gz files

************ SHELL
echo $SHELL- Display current shell name in environment variable SHELL
sh         - Bourne shell
csh        - C shell
ksh        - Korn shell
bash       - GNU Bourne-Again SHell
tcsh       - C shell with filename completion and command line editing
alias      - Create/display alias names for commands (alias dir="ls -lF")
unalias    - Remove an alias name for commands (unalias rm)
listalias  - List user and system aliases
checkalias - Check to see if an alias is defined
newalias   - Install new aliases for user and/or system
elmalias   - Expand and display elm address aliases

************ DATE / TIME
cal        - Display the current months calendar
date       - Gives date AND time (2 for one, not like DOS)

************ TERMINAL
stty       - Set or alter the options for a terminal
clear      - Clear the terminal screen (Like DOS CLS command)
tput clear - Clear the terminal screen (Like DOS CLS command)
banner     - Display a string in big letters

ls         - Lists files, directories, etc. (ls -sail)
cd         - Works like DOS, typed by itself will return you to your home dir
pwd        - Print working directory - tells where in a file system you are
mkdir      - Create a directory - can not be abbreviated
rmdir      - Removes directories - again be careful
rm         - Removes files - use with caution
rename     - Renames a file
cp         - Copies a file, directory from one place to another
mv         - Move a file from one place to another - not the same as copy
mv         - Also renames a file (mv fname fname.new)
file       - Tells what kind of a file it is, text, binary, etc.
find       - Looks for specified files - like Norton file find
whereis    - Locate the binary, source, and man page for a command
which      - Show the path of a command (e.g. which ls   ->   /bin/ls)
ln         - (link) Make a file appear under two different names
lk         - Link editor
umask      - Set the default permission for new file creation (umask 077)
chmod      - Change the permission settings (read, write, execute) on a file
chown      - Change the ownership of a file
chgrp      - Change the group associated with a file
touch      - Update the access and modification times of an existing file
touch      - Create a new empty (zero byte) file

************ TEXT FILE VIEWERS
cat        - Looks at a file raw, no pause like in more (cat /etc/motd)
more       - Shows a file n lines at a time, n being set in env file
less       - Opposite of more - allows backward movement
page       - Same as more, effectively
head       - Looks at the first n lines of a file
tail       - Looks at the last n lines of a file

************ TEXT FILE EDITORS
pico       - Editor (OLD)
nano       - Editor (NEW)
ed         - Editor
emacs      - Editor
e          - Line editor
ex         - Line editor
edit       - Line editor
view       - Visual display editor
vi         - Visual display editor
vedit      - Visual display editor

ispell     - Interactive spelling checking
spell      - Report spelling errors
expand     - Expand tab characters to spaces in a text file
unexpand   - Unexpand spaces to tab characters in a text file
grep       - Search a file for a pattern 
egrep      - Search a file for a pattern using full regular expression
fgrep      - Search a file for a fixed-character string
cut        - Remove sections from each line of files
wc         - Display a count of lines, words and characters
cmp        - Perform a byte-by-byte comparison of two files
sort       - Sort lines of text files
comm       - Display lines in common / not in common, between two sorted lists
diff       - Display line-by-line differences between pairs of text files
uniq       - Remove or report adjacent duplicate lines
tr         - Translate characters
sum        - Display 16-bit checksum and count the blocks in a file
awk        - Pattern scanning and processing language
sed        - Stream editor

************ PRINTING
lp         - Send to a line printer
lprm       - Remove jobs from a line printer queue

************ COMPILERS
gcc        - GNU C and C++ compiler
g++        - GNU C++ compiler
cc         - C compiler

************ SYSTEM STATUS / USER
w          - Who is logged in, and what are they doing
who        - Shows who is logged in - TTYs are Xwindow terms, others dial-in
who am i   - Display your hostname, login name, terminal name, and login time.
whoami     - Display the effective current username
hostname   - Display the system's host name
users      - Display a compact list of users logged in
last       - Shows last logins by user or terminal
netstat    - Shows network status
passwd     - Changes your password
lastcomm   - Show LAST COMMands executed, in reverse order
tty        - Shows current terminal name
uptime     - Show how long the system has been up
groups     - Display a user's group membership
quota -v   - Display a user's disk quota and usage
df         - Shows filesystems mounted and how much disk space is used/free
du         - Shows disk usage for specified directory
uname -a   - Display the name of the current system and OS version

************ PROCESSES
ps         - Shows the status of current processes, etc depending on options
cmd &      - Following a command with '&' runs it in the background
screen     - (virtual) Screen manager with VT100/ANSI terminal emulation
nohup cmd  - Run a command immune to hangups and quits
cron       - Clock daemon, executes commands at specified dates and times
at/batch   - Execute a command or script at a specified time.
sleep      - Suspend execution for a specified interval
atq        - Displays the queue of jobs to be run at specified times
atrm       - Remove jobs spooled by 'at' or 'batch'
jobs -l    - List the active jobs under job control.
kill       - Terminate a process (use kill -9 PID to Immediately kill a PID)
nice       - Run a command at low priority
leave      - Remind you when you have to leave (alarm program)
exec cmd   - Execute command in place of the current shell, which terminates.
login      - Log in to the system
logout     - End current session/hangup (may be exit)
exit       - End current session/hangup


                       DOS to UNIX Command Translations
          A quick reference for users of DOS who are moving to UNIX.

          DOS                    UNIX
          ---                    ----
          HELP                   man, whatis, apropos, info
          DIR                    ls -alF
                                 ls -sail
          DIR/W                  ls -f
                                 ls -F
                                 ls -elf
          RENAME, REN            mv
          ERASE, DEL             rm
          TYPE                   cat
          TYPE filename | MORE   more filename
          COPY                   cp
          MOVE                   mv
          DATE, TIME             date, cal
          VER                    uname -a
          CHDIR, CD              pwd
          CHDIR, CD \            cd
          CHDIR, CD ..           cd ..
          CHDIR, CD path         cd path
          MKDIR, MD              mkdir
          RMDIR, RD              rmdir
          VERIFY=ON              sum
          PROMPT $p$g            PS1=\$PWD\>
          PROMPT $p$g            set prompt="\n%n %~\n%m # "
          CLS                    clear
          ATTRIB                 chmod   (Roughly equivalent)
          ATTRIB +r filename     chmod -w filename
          ATTRIB -r filename     chmod +w filename
          HELP                   man
          SORT                   sort
          TREE                   ls -r
          MODE                   stty
          FIND                   grep, fgrep
          EDLIN                  ed
          PRINT                  lp, lpr, lpq
          EDIT                   edit
          COMP                   cmp, diff
          CHKDSK                 df


                      Set File Permissions - Text method

|||||||||+----[O]ther may e[X]ecute the file        \
||||||||+-----[O]ther may [W]rite to the file        \
|||||||+------[O]ther may [R]ead the file             \
||||||+-------The [G]roup may e[X]ecute the file       \
|||||+--------The [G]roup may [W]rite to the file       > [A]ll Groups
||||+---------The [G]roup may [R]ead the file          /
|||+----------The [U]ser may e[X]ecute the file       /
||+-----------The [U]ser may [W]rite to the file     /
|+------------The [U]ser may [R]ead the file        /
+-------------'d' = This entry is a Directory
              '-' = This entry is a normal file (hyphen)
              'l' = This entry is a symbolic link (ell)

Note: '+' and '-' are used with 'X','W', and 'R'


chmod +x filename         (Add EXECUTE attribute to filename)
chmod -w filename         (Remove WRITE attribute from filename) 
chmod u-w filename        (Removes WRITE attribute from USER (the owner))
chmod go-r filename       (Remove READ attribute from GROUP and OTHER)
chmod go+r filename.html  (Add READ attribute to GROUP and OTHER)
chmod go+w filename       (Add WRITE attribute to GROUP and OTHER)
chmod go+x public_html/   (Add EXECUTE attribute to GROUP and OTHER)
chmod go+rx picture.jpg   (Add READ & EXECUTE attribute to GROUP and OTHER)
chmod a+x ~/public_html   (This will allow ALL people to enter that directory)
chmod a+r ~/public_html/* (To make the files viewable by ALL)


                      Set File Permissions - Octal method

drwxrwxrwx                           r w x     Octal
|\./\./\./                           -----     -----
| |  |  |                            - - -       0
| |  |  +- [O]ther Permission  ->    - - x       1
| |  +---- [G]roup Permission  ->    - w -       2
| +------- [U]ser Permission   ->    - w x       3
+--------- See 'Text method' above   r - -       4
                                     r - x       5
                                     r w -       6
                                     r w x       7


      UGO                    UUUGGGOOO
chmod 700 ~     ->  Private  rwx------ (For me)
chmod 700 .??*  ->  Private  rwx------
chmod 700 *     ->  Private  rwx------
chmod 755 *     ->  Public   rwxr-xr-x (For the world)
chmod 777 *     ->  Public   rwxrwxrwx


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