This section is about Linux and UNIX basic commands and operations, and some
  other explanations and tricks, since this is not a command bible,
  I'll explain each command breafly, with alot of help from the
  man pages and the --help argument (let's all thank the maker for cut & paste).
  Then again, I've seen files that have claimed to be UNIX command bibles
  that are even breafer and hold less commands... though most of the authors
  of those seems to be totally uncapeble of handling a UNIX and cant even spell,
  one of the worst examples I've seen was something like this:
  "The UNIX bible, in this phile is all the UNIX commandz j00 need"
  And after that was a list of commands without arguments... needless to say
  is also that 99% of all UNIX commands were missing.
  Anyway, enough of me making fun of those people now, and on with the tutorial.
  (Which isn't a UNIX command bible, just a note)
  I will refer to "*nix" here, and that means any sort of UNIX system,
  Linux, BSD, Solaris, SunOS, Xenix and so on included.
 ------------------------------------------------------------------------------
 Here are the basic *nix commands, with breaf explanations.
 ------------------------------------------------------------------------------
 adduser
  Syntax: adduser [arguments] <user>
  And can be used with the following arguments:
  -u uid
  -g group
  -G group,...
  -d home directory
  -s shell
  -c comment
  -k template
  -f inactive
  -e expire mm/dd/yy
  -p passwd
  Then there are a few arguments with no explanation:
  -o, -m, -n, and -r
  So say that you wanna add a user named "user" with password "resu"
  belonging to the group root with / as home directory using /bin/tcsh
  as shell, that would look as this:
  adduser -p resu -g root -d / -s /bin/tcsh user
 ------------------------------------------------------------------------------
 alias
  The alias command set's an alias, as this: alias du='du -h'
  This means that whenever you type: du
  it will really do: du -h
  Typing alias by it self will display all set aliases. 

  For more information on the alias command do: help alias
 ------------------------------------------------------------------------------
 apropos
  apropos checks for strings in the whatis database. say that you
  are looking for a manual page about the `shutdown` command.
  Then you can do: apropos shutdown
  for more information, do: man whatis
  Or: man apropos 

 ------------------------------------------------------------------------------
 awk
  awk is a text formatting tool, that is HUGE, it's actually a whole
  language, some say it's not totally wrong to say that awk is not
  far off from a scripting version of C.
  However I wouldent go as far as to say that there resemblance
  is that great.
  awk's most common use is about the same as 'cut', and it works like
  this: awk [argument-1] [argument-2] ....
  Here's some example's of converting an URL:
  echo "http://www.bogus.com/one/two.htm" | awk -F'/' '{print $3}'
  This will return: www.bogus.com
  The -F will set a delimiter, and the '{print $3}' will print the
  third feild, separated by the delimiter, which is www.bogus.com,
  because there is 2 slashes, which makes the second slash the second
  feild, and so www.bogus.com is the third feild.
  Here's another example:
  echo "http://www.bogus.com/one/two.htm" | awk -F'/' '{print $(NF)}'
  This will return: two.htm
  The -F set's the delimiter, which once again is /, but this time
  we have used $NF which always resembles the last feild.
  Another example with NF is this: 

  echo "http://www.bogus.com/one/two.htm" | awk -F'/' '{print $(NF - 1)}'
  This will return: one
  Because $(NF - 1) means the last feild minus one feild, which always
  will be the next last feild.
  You only have to use the ()'s around variables when you do something
  with them like here "$(NF - 1)", but you can use $(var) all the time
  if you want.
  Here's another example: 

  echo "http://www.bogus.com/one/two.htm" | awk -F'/' '{print $3 "/" $(NF - 1)}'
  This will return: www.bogus.com/one
  It will first print out the third feild separated by /'s, which is
  www.bogus.com, then it will print a /, and then it will print out
  the next last feild which is one. 

  Here is a very shoer final example of awk:
 echo "http://www.bogus.com/one/two.htm" | awk '{ while  ( $(1) ) print }'
  This will return: "http://www.bogus.com/one/two.htm" forever.
  The "while ( $(1) )" means that as long as there is first feild,
  it will print the line line.
  And since there will always be a first feild it will continue
  forever.
  while in awk works as this: while ( condition ) action  

  As I said, awk is huge and is actually a whole language, so
  to explain all of it it would need a tutorial of it's own.
  So I will not go any deeper into awk here, but you can as always
  read it's manual page which is quite large.
  So, for more info do: man awk  

  ------------------------------------------------------------------------------
 basename
  basename will strip directory and suffix from filenames.
  This command only have the two following flags:
  --help      display this help and exit
  --version   output version information and exit
  It works like this:
  alien:~$ basename /usr/local/bin/BitchX -a
  BitchX
  alien:~$ basename http://www.domain.com/path/to/file.html
  file.html
  alien:~$
  For more info do: man basename
 ------------------------------------------------------------------------------
 bc
  A precision calculator, can be used with the following arguments:
  -l     Define the standard math library.
  -w     Give warnings for extensions to POSIX bc.
  -s     Process exactly the POSIX bc language.
  -q     Do not print the normal GNU bc welcome.
  -v     Print the version number and copyright and quit.
 -------------------------------------------------------------------------------
 BitchX
  BitchX is usually not default on any system, but it's the far
  msot advanced IRC client to *nix.
  BitchX started as a script to ircii (ircii is irc2 an extended
  irc protocol, also EPIC which is more bareboned then BitchX is
  made from ircii), until BitchX got hard coded to the protocol
  in C, by panasync I belive.
  BitchX has alot of arguments but can be executed without any
  arguments.
  This is the synatx: BitchX [arguments] <nickname> <server list>
  And here are the arguments anyway:
  -H <hostname>	this is if you have a virtual host.
  -c <#channel>	auto join a channel, use a  infront of the #
  -b		load .bitchxrc or .ircrc after connecting to a server
  -p <port>	connect on port (default is 6667)
  -f           	your terminal uses flow controls (^S/^Q),
  so BitchX shouldn't
  -F           	your terminal doesn't use flow control (default)
  -d		dumb terminal mode (no ncurses)
  -q		dont load the rc file ~/.ircrc
  -r <file>       loads file as list of servers to connect to
  -n <nickname>	set the nickname to use
  -a              adds default servers and command line servers
  to server list
  -x          	runs BitchX in "debug" mode
  -Z              use NAT address when doing dcc
  -P              toggle check pid.nickname for running program
  -v		show client version
  -B              fork BitchX and return you to shell. pid check on.
  -l <file>    	loads <file> in place of your ~/.ircrc
  -L <file>    	loads <file> in place of your .ircrc and
  expands $ expandos 

  The most common way of starting BitchX is this, say that you want
  to have the nick 'Bash' on server irc.bogus.com, then you can do:
  BitchX Bash irc.bogus.com 

  There is so much to say about BitchX that it would need a tutorial
  of it's own, I'm currently writing a BitchX script, so maybe
  I'll write a BitchX tutorial some time =)
 -------------------------------------------------------------------------------
 bzcat
  bzcat will uncompress a .bz2 file 'on the fly' as it cat's it.
  the actual file will remain compressed after bzcat has displayed
  the contents.
  bzcat has to my knowlidge only one switch, and that's
  -s, that uses less memory.
  bzcat works like this: 

  bzcat file.bz2
  This can be good if you wanna search something in a text file
  that has been bzip2'd.
  Examples:
  bzcat file.bz2 | grep 'text string'
  bzcat file.bz2 | wc -l
 -------------------------------------------------------------------------------
 bzip2 

  Compression tool, compresses harder then the standard gzip.
  bzip2 can be used with the following arguments:
  -h --help           print this message
  -d --decompress     force decompression
  -z --compress       force compression
  -k --keep           keep (don't delete) input files
  -f --force          overwrite existing output files
  -t --test           test compressed file integrity
  -c --stdout         output to standard out
  -q --quiet          suppress noncritical error messages
  -v --verbose        be verbose (a 2nd -v gives more)
  -L --license        display software version & license
  -V --version        display software version & license
  -s --small          use less memory (at most 2500k)
  -1 .. -9            set block size to 100k .. 900k
  Normally used as: bzip2 -d file.bz2 (to decompress a file)
  or bzip2 -z file (to compress a file) 

  -------------------------------------------------------------------------------
 cat
  cat followed by a filename will bring the contents of the file
  out to the screen (stdout), and can be used with the following
  arguments:
  -A, --show-all           equivalent to -vET
  -b, --number-nonblank    number nonblank output lines
  -e                       equivalent to -vE
  -E, --show-ends          display $ at end of each line
  -n, --number             number all output lines
  -s, --squeeze-blank      never more than one single blank line
  -t                       equivalent to -vT
  -T, --show-tabs          display TAB characters as ^I
  -u                       (ignored)
  -v, --show-nonprinting   use ^ and M- notation, except for LFD and TAB
  --help               display this help and exit
  --version            output version information and exit
 -------------------------------------------------------------------------------
 cc
  C compiler, can be used with ALOT of arguments, do a man cc to find
  out just how many, it's normally used to compile a .c source file to an
  executable binary, like this:
  cc -o program program.c
 -------------------------------------------------------------------------------
 cd
  change directory, works as this:
  cd /way/to/directory/I_want_to/be/in/
  No further explanation needed.
 -------------------------------------------------------------------------------

 chattr
  This is a very powerful command with which you can change the
  attributes on an ext2 file system.
  This means that you can make a file impossible to remove
  for as long as the attributes are there.
  The attributes that can be added or removed are the follwoing: 

  A	Don't update atime.
  S	Synchronous updates.
  a	Append only.
  c	Compressed.
  i	Immutable.
  d	No dump.
  s	Secure deletion.
  u	Undeletable.
  So here is an example: 

  chattr +iu /etc/passwd
  This makes it impossible to remove the /etc/passwd file unless
  you first do:
  chattr -iu /etc/passwd
  This can also be good for the logs, esecially, with the a attribute.
  To see the attributes, use: lsattr
  For more info do: man chattr
 -------------------------------------------------------------------------------
 chmod
  chmod is a very useful command, it changes the rights of any file.
  To understand this command you need to understand how the permission
  line works: 

  -rwxr-xr-x    1 alien    users          58 Feb  7 13:19 file1
  -rw-r--r--    1 alien    users        3.1k Feb  3 15:47 file2 

  Let's break the -rwxr-xr-x down into 4 sections:
  - rwx r-x r-x
  The first - you can not change, that tells what sort of file it is,
  as if it's a special file, a directory or a normal file.
  The second rwx is the rights of the owner of the file.
  The third r-x is the rights the group of the file has.
  And the fourth r-x tells us what right others/anyone else has.
  The rights can be: 

  r	read rights.
  w	write rights.
  x 	execute rights.
  s       suid (su id, execute with someome else's uid, usually root)
  t       saves the programs text on the swap device
  X	executes file only if it's in a dir that has execute rights 

  Then we need to know in what of those 3 last fields to set those
  rights, they can be set to: 

  a	all (changes the 3 fields syncroniously)
  u	user
  g	group
  o	others/anyone else 

  You can add or remove rights with the following arguments: 

  +	add a right
  -	remove a right
  =	absolute right
  So say now that we have a file called file1, that looks like this: 

  -rwxr-xr-x    1 alien    users          58 Feb  7 13:19 file1 

  And we wanna take away all execution rights.
  Then we can either do:
  chmod a-x file1
  or
  chmod ugo-x file1
  And if we wanna make a file executable to everyone in it's group,
  in this case the group "users", then we do:
  chmod g+x file1
  The other way to do this, is to use octal numbers to set the
  rights in the permission line.
  This requires a bit more thinking if your not use to it, but here's
  how it works: 

  First we break up the permission line into 3 sections again (not
  counting the leading - or d), and then we put numbers on each
  of the 3 fields in each of the 3 sections.
  - rwx rwx rwx
  421 421 421
  Now to change a line to say: -rwxrx-r-x
  You would:
  x and r in the last field, that would mean 1+4=5, then the same thing
  in the middle field, and last we have r, w and x in the first so then
  we count them all, 1+2+4=7.
  If we now line up our results of this little mathematic we get: 755
  And so to change a permission line to -rwxrx-r-x we do:
  chmod 755 <file>
  Here's how it looks:
  Oct     Bin    Rights
  0         0 	---
  1         1 	--x
  2        10 	-w-
  3        11 	-wx
  4       100 	r--
  5       101 	r-x
  6       110 	rw-
  7       111 	rwx
  Then we have the suid stuff for this with octal counting, that you set
  before the normal rights, I'll explain that in a bit, first here
  is the number codes for the special options as suid.
  7*** SUID (user & group and set's file +t)
  6*** SUID (user & group)
  5*** SUID +t (saves the files text to the swap partition and SUID user)
  4*** SUID (user)
  3*** SUID (group and set's file +t)
  2*** SUID (group)
  1*** +t (saves the files text to the swap partition)
  0*** nothing
  Here's how it looks:
  Oct	Bin    Rights
  -	--- rwx rwx rwx
  0  	  0 --- --- ---
  1	  1 --- --- --t
  2	 10 --- --s ---
  3	 11 --- --s --t
  4	100 --s --- ---
  5	101 --s --- --t
  6	110 --s --s ---
  7	111 --s --s --t
  So if you have a file that we can call 'foo.sh' and you wanna make
  so that only the user has write permissions to it, the user
  and group has read and execute permissions, and all others has no
  rights at all to it.
  Then we would count: others, 0, group 5, user 7, and then to SUID
  the group we add a 2 in front of what we have, which means:
  chmod 2750 foo.sh
  This will make foo.sh's permission line look like this: 

  -rwxr-s--- 

  To do the exact same with characters, you do:
  chmod u+rwx,go-rwx,g+s foo.sh
  The most common premissions for files is  

  Executeble:      (755)   -rwxr-xr-x
  Non-Executeble:  (644)   -rw-r--r--
  The easyest way of setting these is by eather do: 

  chmod 755 file
  or
  chmod =rwxrxrx file 

  chmod 644 file
  or
  chmod =rwrr file
  For more information, do: man chmod
 -------------------------------------------------------------------------------
 chown
  chown changes owner of a file, it can actually also change the group.
  it works like this:
  chown user file
  This would change the owner of the file to user, but note that
  you can not change to owner of a file to a user that's owned
  by someone else, same thing is that you can not change another
  users files so that you own them.
  Basicly, you need to be root to for this command in most cases.
  If you wanna change both the user and the group of a file, you do
  like this:
  chown user.group file
  That would change the owner of the file to user and the group
  of the file to group.
  For more info on this do: man chown
 -------------------------------------------------------------------------------
 chroot
  runs a command or interactive shell with special root directory.
  It works like this: 

  chroot /new/root/directory/ command 

  This can be good for some programs or commands, that rather
  would have / as root directory then ~/ etc.
 -------------------------------------------------------------------------------
 cmp
  compares 2 files for differences, it can be used with the
  following arguments:
  -l    Print the byte number (decimal) and the differing byte
  values (oc- tal) for each difference.
  -s    Print nothing for differing files; return exit status only. 

  It works like this: 

  cmp file1 file2
  Or
  cmp -s file1 file2
  Not a very big, but still useful command.
 -------------------------------------------------------------------------------
 cp
  copy, copy's a file from one location to another, may also copy
  one filename to another, used as this:
  cp file /some/other/dir/
  or
  cp file file.old
 -------------------------------------------------------------------------------
 crontab
  Crontab has already been explained in this tutorial.
 -------------------------------------------------------------------------------
 cut
  cut is a very powerful command, that allows you to cut in texts,
  It works like this: cut [arguments] <file>
  -b, --bytes=LIST
  output only these bytes
  -c, --characters=LIST
  output only these characters
  -d, --delimiter=DELIM
  use DELIM instead of TAB for field delimiter
  -f, --fields=LIST
  output only these fields
  -n
  (ignored)
  -s, --only-delimited
  do not print lines not containing delimiters
  --output-delimiter=STRING
  use STRING as the output delimiter
  the default is to use the input delimiter
  --help
  display the help and exit
  --version
  output version information and exit
  One of the many ways to use it is like this, say that you have a file
  named "hostlist" that contains this:
  beta.linux.com has address 216.200.201.197
  shiftq.linux.com has address 216.200.201.195
  irc.linux.com has address 216.200.201.199
  oreilly.linux.com has address 208.201.239.30
  srom.linux.com has address 204.94.189.33
  admin.linux.com has address 216.200.201.194
  And you ONLY wanna list the IP's from it, then you do this: 

  cut -d ' ' -f 4 testfile
  That will output only the IP's, first we set the delimiter to ' '
  which means a space, then we display the 4'th field separated by
  the delimiter, which here is the IP's. 

  Or that you have a file (say named column.txt) that contains this:
  something                if we have to
  or someone              cut and paste
  likes to write          the columns.
  in columns, we          So what do
  don't like that          we do about
  especially not          this ?
  To cut out each column is done like this: 

  cut -c 1-14 column.txt
  cut -c 23-40 column.txt
  This would fist cut the file lengthwise and display characters
  1-14 and then the same thing again but characters 23-40.
  Now a simple way to get them in a long row instead of columns
  in a file is this:
  cut -c 1-14 column.txt > no-columns.txt
  cut -c 23-40 column.txt >> no-columns.txt
 -------------------------------------------------------------------------------
 date
  date alone returns the current date and time in the following format: 

  day month  date hr:min:sec timezone year
  But can be executed with the following arguments:
  %%   a literal %
  %a   locale's abbreviated weekday name (Sun..Sat)
  %A   locale's full weekday name, variable length (Sunday..Saturday)
  %b   locale's abbreviated month name (Jan..Dec)
  %B   locale's full month name, variable length (January..December)
  %c   locale's date and time (Sat Nov 04 12:02:33 EST 1989)
  %d   day of month (01..31)
  %D   date (mm/dd/yy)
  %e   day of month, blank padded ( 1..31)
  %h   same as %b
  %H   hour (00..23)
  %I   hour (01..12)
  %j   day of year (001..366)
  %k   hour ( 0..23)
  %l   hour ( 1..12)
  %m   month (01..12)
  %M   minute (00..59)
  %n   a newline
  %p   locale's AM or PM
  %r   time, 12-hour (hh:mm:ss [AP]M)
  %s   seconds since 00:00:00, Jan 1, 1970 (a GNU extension)
  %S   second (00..60)
  %t   a horizontal tab
  %T   time, 24-hour (hh:mm:ss)
  %U   week number of year with Sunday as first day of week (00..53)
  %V   week number of year with Monday as first day of week (01..52)
  %w   day of week (0..6);  0 represents Sunday
  %W   week number of year with Monday as first day of week (00..53)
  %x   locale's date representation (mm/dd/yy)
  %X   locale's time representation (%H:%M:%S)
  %y   last two digits of year (00..99)
  %Y   year (1970...)
  %z   RFC-822 style numeric timezone (-0500) (a nonstandard extension)
  %Z   time zone (e.g., EDT), or nothing if no time zone is determinable
  For example, if you want to the time as hr:min:sec day, you would do:
  date +'%H:%M:%S %a'
  Or if you wanted to display the name of the month only, you would do:
  date +%B
 -------------------------------------------------------------------------------
 dc
  dc is an arbitrary precision calculator.
  man dc for more info.
 -------------------------------------------------------------------------------
 dd
  disk duplicator, this is a very powerful command, that is
  useful for doing backups as well as creating boot floppy's
  from images.
  Say now that you have a Slackware standard boot floppy image (bare.i)
  and you want to write it to a floppy, then you do this: 

  dd if=bare.i of=/dev/fd0 conv=sync
  If you instead have a RedHat or Mandrake boot image, just replace
  the bare.i in the line with boot.img, under the condition that
  you are standing in a directory that contains that specific image.
  The conv=sync part is just there to make sure that the disks are
  synced.
  dd is a quite big command so I suggest you take a look at the man page.
 -------------------------------------------------------------------------------
 declare
  declare will declare a variable and may set attributes to it.
  The attributes declare can set or use with the following flags are:
  -p        show variable with attributes.
  -a        to make a variable(s) an array (if supported)
  -f        to select from among function names only
  -F        to display function names without definitions
  -r        to make variable(s) readonly
  -x        to export variable(s)
  -i        to make variable(s) have the `integer' attribute set
  Using `+' instead of `-' turns off the given attribute(s) instead
  of setting them.
  If declare is used within a function, the variables will be
  local, the same way as if the `local` command had been used.
  The -r option works the same as the `readonly` command.
  And the -r option can not be removed once it's set.
  Here's a short example:
  declare -xr foo=bar
  This would do the same as to do:
  export foo=bar; readonly foo
  For more info on this, do: help declare
 -------------------------------------------------------------------------------
 depmod
  depmod loads kernel modules, and is a very powerful command,
  it's greatest use is that it can reload all kernel modules
  in a single line: 

  depmod -a 

  This is especially good if you have recompiled some modules and
  installed them, and you don't wanna reboot the system.
  The command also allows you to load single modules or several
  modules, like this:
  depmod module1.o module2.o ... etc. 

  For more info, man depmod
 -------------------------------------------------------------------------------
 df
  Reports filesystem disk space usage.
  df can be used with the following arguments:
  -a, --all
  include filesystems having 0 blocks 

  --block-size=SIZE use SIZE-byte blocks 

  -h, --human-readable
  print sizes in human readable format (e.g., 1K 234M 2G)
  -H, --si
  likewise, but use powers of 1000 not 1024
  -i, --inodes
  list inode information instead of block usage
  -k, --kilobytes
  like --block-size=1024
  -l, --local
  limit listing to local filesystems
  -m, --megabytes
  like --block-size=1048576
  --no-sync
  do  not  invoke  sync  before  getting  usage  info (default)
  -P, --portability
  use the POSIX output format
  --sync invoke sync before getting usage info
  -t, --type=TYPE
  limit listing to filesystems of type TYPE
  -T, --print-type
  print filesystem type
  -x, --exclude-type=TYPE
  limit listing to filesystems not of type TYPE
  -v     (ignored)
  --help display this help and exit
  --version
  output version information and exit
  My favorite is to use: df -h
 -------------------------------------------------------------------------------
 dhcpcd
  dhcpcd is used to obtain an IP if you have dynamic IP on a LAN
  such as a cable modem with dynamic IP.
 -------------------------------------------------------------------------------
 dialog
  The dialog command has already been explained in this tutorial.
 -------------------------------------------------------------------------------
 diff
  diff is a very large command that finds the difference between
  two files, it's very handy to have to make patches.
  The basic use of diff is as follows:
  diff file1 file2
  for more and full info on this command, do: man diff 

  -------------------------------------------------------------------------------
 dir
  Same as "ls".
 -------------------------------------------------------------------------------
 dmesg
  dmesg can print or control the kernel ring buffer.
  by default it'll show a log of loaded and unloaded modules
  and other kernel events, like initialization if RAM disks etc.
  (this is flushed at each reboot)
  This is useful to make a boot.messages file, bu simply doing this:
  dmesg > boot.messages
  If there is any errors at the boot up this command is the first
  you would use to try to determen the error.
  This is the syntax of dmesg (cut'n'paste of the man page): 

  dmesg [ -c ] [ -n level ] [ -s bufsize ]
  The options (-c/-n/-s) means the following:
  -c
  clear the ring buffer contents after printing.
  -s bufsize
  use  a  buffer  of bufsize to query the kernel ring
  buffer.  This is 8196 by default (this matches  the
  default  kernel  syslog  buffer  size in 2.0.33 and
  2.1.103).  If you have set  the  kernel  buffer  to
  larger  than  the  default  then this option can be
  used to view the entire buffer.
  -n level
  set the level at which logging of messages is  done
  to  the  console.   For  example, -n 1 prevents all
  messages, expect panic messages, from appearing  on
  the  console.   All  levels  of  messages are still
  written to /proc/kmsg, so syslogd(8) can  still  be
  used  to  control  exactly  where  kernel  messages
  appear.  When the -n option is used, dmesg will not
  print or clear the kernel ring buffer.
  When both options are used, only the last option on
  the command line will have an effect. 

  An example of usage is this:
  dmesg -c -s 16392 

  This would print the kernel ring buffer (with a buffer size of 16392)
  And then flush the contents.
  For more info on this command do: man dmesg
 -------------------------------------------------------------------------------
 do
  do just does what it says, and is used in among others
  'while' loops, if you have read the whole tutorial this far
  (and have photographic memory) you understand what I'm saying.
 -------------------------------------------------------------------------------
 domainname
  See hostname.
 -------------------------------------------------------------------------------
  du
  du shows estimated file space usage.
  du is a good command to show how much space a directory takes up.
  I prefer to use it with the -h argument (human readable, see df).
  du has lots of arguments, do `man du` for a full list.
 -------------------------------------------------------------------------------
 echo
  echo will redisplay anything you put after it.
  This is perhaps the most used command in bash scripting, and
  very useful in everyday *nix handling as well, I'll get back
  to that in a moment. but first, echo has the following arguments:
  -n     do not output the trailing newline
  -e     enable interpretation of the backslash-escaped characters
  listed below
  -E     disable interpretation of those sequences in STRINGs
  --help display this help and exit (should be alone)
  --version
  output  version  information  and  exit  (should be alone)
  AND these:
  e       backslash
  c       suppress trailing newline
  a       alert (BELL)
  f	newline and vertical tab
  n	new line
  r	delete recursively (rest of line backwards)
  t	vertical tab
  v	newline and vertical tab (vertical tab ?)
  xa	new line
  xb	newline and vertical tab
  xc	newline and vertical tab
  xd	delete rest of line forward
  xe	ascii ... screws up the console (type reset to get it back) 

  So to get a bell (beep) you just do: 

  echo -e "a"
  Or to screw up your console, do:
  echo -e "xe"
 -------------------------------------------------------------------------------
 eject
  With eject you can eject removable medias, such as tapes, JAZ, ZIP,
  CD-rom and so on.
  The command is pretty self explanatory, and can be used with the
  following arguments: 

  -h	 --help
  -v	 --verbose
  -d	 --default
  -a	 --auto
  -c	 --changerslot
  -t	 --trayclose
  -n	 --noop
  -r	 --cdrom
  -s	 --scsi
  -f 	 --floppy
  -q	 --tape
  The eject command is used as follows: eject [argument] <name>
  The name is the name of th drive, either from /dev, /mnt or
  by it's mountpoint name.
 -------------------------------------------------------------------------------
 else
  Used in 'if' statements, and does what it says, used like this:
  if [ "arg1" = "arg2" ]; then echo "match" ; else echo "no match" ; fi
 -------------------------------------------------------------------------------
 env
  Display the enviorment settings.
  Can be used with the following arguments:
  -i, --ignore-environment. start with an empty environment
  -u, --unset=NAME. remove variable from the environment
  --help display this help and exit
  --version
 -------------------------------------------------------------------------------
 exit
  exit is used to kill the current process.
  It can either be used to logout or to kill a running script from
  within the script, in the later case it can be used with a
  return number as argument, ie. exit 0
 -------------------------------------------------------------------------------
 expr
  expr is a counter or command line calculator, it can handle most
  simple integer calculations.
  It can use all the normal ways of counting including boolean
  operators, such as | OR, != NOT IS, and so on.
  It's simply used as this: expr 1 + 1
  One thing to remember, since this is in the command line, if you use
  * (times), you have to use it like this: expr 2 '*' 2
  The ' precise quote makes sure that the star is not treated
  as a wildcard. 

  -------------------------------------------------------------------------------
  fdisk
  fdisk is the classic disk handler, with fdisk you can edit your
  hard drive(s) in alot of ways, as adding or removing partitions,
  list the partitions and so on.
  You start fdisk as this: fdisk /dev/<disk to veiw/edit>
  This may be a disk such as /dev/hda /dev/hdb /dev/hdc and so on.
  Note that you can not determen a specific HD partition to
  start from, since fdisk operates on the whole HD.
  When you start fdisk you will have the following commands,
  followed by there explanation:
  a   toggle a bootable flag
  b   edit bsd disklabel
  c   toggle the dos compatibility flag
  d   delete a partition
  l   list known partition types
  m   print this menu
  n   add a new partition
  o   create a new empty DOS partition table
  p   print the partition table
  q   quit without saving changes
  s   create a new empty Sun disklabel
  t   change a partitions system id
  u   change display/entry units
  v   verify the partition table
  w   write table to disk and exit
  x   extra functionality (experts only)
  And in 'x' the extra functionality (experts only) mode.
  b   move beginning of data in a partition
  c   change number of cylinders
  d   print the raw data in the partition table
  e   list extended partitions
  g   create an IRIX partition table
  h   change number of heads
  m   print this menu
  p   print the partition table
  q   quit without saving changes
  r   return to main menu
  s   change number of sectors/track
  v   verify the partition table
  w   write table to disk and exit
  For more info on fdisk, do: man fdisk
 -------------------------------------------------------------------------------
 file
  The file command will tell you what type of file a file is.
  file basically works like this:
  file [ -bciknsvzL ] [ -f namefile ] [ -m magicfiles ] file
  The options are as follows:
  -b      Do not prepend filenames to  output  lines  (briefmode).
  -c      Cause  a  checking  printout of the parsed form of
  the magic file.  This is usually used in  conjunction
  with  -m  to  debug  a new magic file before installing it.
  -f namefile
  Read the names of the files to  be  examined  from
  namefile  (one per line) before the argument list.
  Either namefile or at least one filename  argument
  must  be  present; to test the standard input, use
  ``-'' as a filename argument.
  -i      Causes  the  file  command  to  output  mime  type
  strings  rather  than  the  more traditional human
  readable  ones.  Thus  it  may  say  ``text/plain;
  charset=us-ascii''  rather than ``ASCII text''. In
  order for this option to work,  file  changes  the
  way  it  handles  files  recognised by the command
  it's self (such as many of the  text  file  types,
  directories  etc), and makes use of an alternative
  ``magic'' file.  (See ``FILES'' section, below).
  -k      Don't stop at the first match, keep going. 

  -m list
  Specify an  alternate  list  of  files  containing
  magic  numbers.   This  can be a single file, or a
  colon-separated list of files.
  -n      Force stdout to be flushed  after  check  a  file.
  This  is  only useful if checking a list of files.
  It is intended to be used by programs  want  filetype
  output from a pipe. 

  -v      Print the version of the program and exit.
  -z      Try to look inside compressed files.
  -L      option  causes  symlinks  to  be  followed, as the
  like-named option in ls(1).  (on systems that support
  symbolic links).
  -s      Normally, file only attempts to read and determine
  the type of argument files which  stat(2)  reports
  are   ordinary  files.   This  prevents  problems,
  because reading special files  may  have  peculiar
  consequences.   Specifying  the  -s  option causes
  file to also read argument files which  are  block
  or  character  special  files.  This is useful for
  determining the filesystem types of  the  data  in
  raw  disk  partitions,  which  are  block  special
  files.  This option also causes file to  disregard
  the file size as reported by stat(2) since on some
  systems it reports a zero size for raw disk partitions.
  Here's a very simple usage example:
  file /bin/sh
  file script.sh
  For more info do: man file
 -------------------------------------------------------------------------------
 find
  find is a very powerful and useful command, it is as good for finding
  a file name as to helping you secure your system against hackers. 

  find works basicly like this: find <path> [argument] <file> 

  You REALLY need to read it's manual page, if you wanna know
  about this command, but here are some examples:
  Find all files that are set suid root:
  find / -perm +4000 

  Find all regular files named core (this will skip directory's):
  find / -type f -name core
  Find all filenames that contains the word 'conf':
  find / -name *conf*
  Find all directory's that ends with 'bin':
  find / -type d -name *bin
  Find all files named test.sh and execute them:
  find / -name test.sh -exec {} ; 

  Find all regular files that contains the word .exe and
  remove them by force without asking:
  find / -type f -name *.exe -exec rm {} -rf ;
  Even if you are root you may come across errors like this: 

  find: /proc/10502/fd: Permission denied
  The easiest way to deal with this is to add a: 2>/dev/null
  after your command string, that will direct all such errors
  to /dev/null (the black hole of UNIX :P)
 -------------------------------------------------------------------------------
 ftpwho
  ftpwho is a command where you can see how many users there are
  logged on to your ftp, under the condition that you have an
  ftp server on your system that is.
 -------------------------------------------------------------------------------
 g++
  GNU C++ compiler.
  See it's man page.
  -------------------------------------------------------------------------------
 gcc
  GNU C Compiler.
  See cc
  And see the gcc man page
 -------------------------------------------------------------------------------
 gdb
  GNU Debugger, has ALOT of commands and arguments,
  see: man gdb.
 -------------------------------------------------------------------------------
 gpm
  gpm is the Linux mouse daemon, it's unspareble when it comes to
  working an a console, cut & paste is a wonderful thing.
  gpm works basicly as this: gpm [options]
  The most common options would be as this:
  gpm -m /dev/mouse -t ps2
  This would start a PS/2 mouse, under the conditions that the
  PS/2 port (/dev/psaux) is linked to the mouse device (/dev/mouse).
  You can use "gpm -m /dev/psaux -t ps2" just as well.
  Or if you have a serial mouse no COM1 you can start it like this: 

  gpm -m /dev/cua0 -t ms
  The -m argument means, the mouse device, and the -t argument is
  the protocol it's going to use.
  For a list of all gpm's arguments do: gpm -h
  And for a list of all the possible mouse protocols, do: gpm -t help
  The basic console cut & paste functions for a 3 button mouser is: 

  Left button - hold and drag to highlight text (copy's text to memory). 

  Middle button - pastes text that are in memory (see left button) 

  Right button - mark a starting point with a single left click and then
  mark an end point with the right button to highlight the whole section.
  Once you get it to work, you may add the line to: /etc/rc.d/rc.local
 -------------------------------------------------------------------------------
 grep
  grep is another of the very powerful commands
 -------------------------------------------------------------------------------
 halt
  This will halt (shutdown -h now) your system.
 -------------------------------------------------------------------------------
 hdparm
  hdparm is a powerful tool to control your hard drives.
  It works like this: hdparm <arguments> <hard drive>
  The arguments can be:
  -a   get/set fs readahead
  -A   set drive read-lookahead flag (0/1)
  -c   get/set IDE 32-bit IO setting
  -C   check IDE power mode status
  -d   get/set using_dma flag
  -D   enable/disable drive defect-mgmt
  -E   set cd-rom drive speed
  -f   flush buffer cache for device on exit
  -g   display drive geometry
  -h   display terse usage information
  -i   display drive identification
  -I   read drive identification directly from drive
  -k   get/set keep_settings_over_reset flag (0/1)
  -K   set drive keep_features_over_reset flag (0/1)
  -L   set drive doorlock (0/1) (removable harddisks only)
  -m   get/set multiple sector count
  -n   get/set ignore-write-errors flag (0/1)
  -p   set PIO mode on IDE interface chipset (0,1,2,3,4,...)
  -P   set drive prefetch count
  -q   change next setting quietly
  -r   get/set readonly flag (DANGEROUS to set)
  -R   register an IDE interface (DANGEROUS)
  -S   set standby (spindown) timeout
  -t   perform device read timings
  -T   perform cache read timings
  -u   get/set unmaskirq flag (0/1)
  -U   un-register an IDE interface (DANGEROUS)
  -v   default; same as -acdgkmnru (-gr for SCSI, -adgr for XT)
  -V   display program version and exit immediately
  -W   set drive write-caching flag (0/1) (DANGEROUS)
  -X   set IDE xfer mode (DANGEROUS)
  -y   put IDE drive in standby mode
  -Y   put IDE drive to sleep
  -Z   disable Seagate auto-powersaving mode
  Some examples:
  hdparm -Tt /dev/hda	(Time the cache/device read times)
  hdparm -c 1 /dev/hda	(This made my HD read the cache twice as fast)
  hdparm -Yy /dev/hda	(This will totally power down the HD until
  it's needed, very useful to save power
  or if you just need a minutes silence)
  For more info: man hdparm
 -------------------------------------------------------------------------------
 head
  the head command by default brings up the 10 top lines of a file,
  but can be used with these arguments: 

  -<n>			 where the <n> is the number of lines to get
  -c, --bytes=SIZE         print first SIZE bytes
  -n, --lines=NUMBER       print first NUMBER lines instead of first 10
  -q, --quiet, --silent    never print headers giving file names
  -v, --verbose            always print headers giving file names
  --help               display this help and exit
  --version            output version information and exit
  Here's some examples:
  head file
  head -1 file
  head -50 file
  head -c 100 file
  This command can prove to be very useful.
 -------------------------------------------------------------------------------
 help
  help is a command that shows information on built in commands.
  like ., cd, jobs, %, test, etc.
  It works like this: help <command> 

  -------------------------------------------------------------------------------
 hexdump
  hexdump is a command that will give a hex dump of any file.
  For more info on this command do: man hexdump
 -------------------------------------------------------------------------------
 hexedit
  hexedit is a hex editor, very good for debugging binarys,
  hexedit has alot of internal commands, do: man hexedit
  for more help on it.
 -------------------------------------------------------------------------------
 hostname
  With no arguments it displays the current hostname.
  But can also set a new hostname, here are it's arguments:
  -s, --short           short host name
  -a, --alias           alias names
  -i, --ip-address      addresses for the hostname
  -f, --fqdn, --long    long host name (FQDN)
  -d, --domain          DNS domain name
  -y, --yp, --nis       NIS/YP domainname
  -F, --file            read hostname or NIS domainname from given file
  Here's an example if you wanna change your hostname: 

  hostname -F /etc/HOSTNAME
 -------------------------------------------------------------------------------
 id
  Shows you a users ID, default your user UID, GID and group name.
  The command has some arguments it can be used with, like this:
  id [argument] <user>
  Here are the arguments:
  -a              ignore, for compatibility with other versions
  -g, --group     print only the group ID
  -G, --groups    print only the supplementary groups
  -n, --name      print a name instead of a number, for -ugG
  -r, --real      print the real ID instead of effective ID, for -ugG
  -u, --user      print only the user ID
  --help      display this help and exit
  --version   output version information and exit
  So `id -u` will return '0' if you are root (same as `echo $UID`).
 -------------------------------------------------------------------------------
 ifdown
  ifdown is a command that will let you shutdown (deactivate) any
  ethernet device. I works as this: ifdown <device>
  So say that you have an eth0 running that you wanna shut down, then
  you just do this: ifdown eth0
  For more info on how to set up an ethernet device,
  see section 7 (Networking) in this tutorial. 

  -------------------------------------------------------------------------------
 ifup
  ifup works the same as ifdown, but activates the ethernet device
  rather then deactivate it.
  For more info on how to set up an ethernet device,
  see section 7 (Networking) in this tutorial.
 -------------------------------------------------------------------------------
 init
  init sets the runlevel for you.
  If you have read the whole of this tutorial to this point you know
  about where to look for what they mean.
  So if you do: init 0
  The system will shutdown and halt there.
  And if you type: init 6
  The system will reboot, etc.
 -------------------------------------------------------------------------------
 insmod
  insmod tries to installs a loadable module in the running kernel.
  It works like this:  

  insmod [arguments] <-o module_name> object_file [ sym-bol=value ... ] 

  Here are the possible arguments:
  -f, --force         Force loading under wrong kernel version
  -k, --autoclean     Make module autoclean-able
  -m                  Generate load map (so crashes can be traced)
  -o NAME
  --name=NAME     Set internal module name to NAME
  -p, --poll          Poll mode; check if the module matches the kernel
  -s, --syslog        Report errors via syslog
  -v, --verbose       Verbose output
  -V, --version       Show version
  -x                  Do not export externs
  -X                  Do export externs (default)
  An example of how to use this is:
  insmod -o 3c90x /lib/modules/2.2.14/net/3c90x.o
  This would load the 3c90x.o module with 3c90x as name.
 -------------------------------------------------------------------------------
 install
  install is a command that installs a file properly,
  it works like this: install [arguments] source destination
  The arguments can be any of the following:
  -b, --backup
  make backup before removal
  -c
  (ignored) 

  -d, --directory
  treat all arguments as directory names; create all
  components of the specified directories 

  -D
  create all leading components of DEST except the last,
  then copy SOURCE to DEST;  useful in the 1st format 

  -g, --group=GROUP
  set group ownership, instead of process' current group 

  -m, --mode=MODE
  set permission mode (as in chmod), instead of rwxr-xr-x 

  -o, --owner=OWNER
  set ownership (super-user only) 

  -p, --preserve-timestamps
  apply access/modification times of SOURCE files to
  corresponding destination files 

  -s, --strip
  strip symbol tables, only for 1st and 2nd formats 

  -S, --suffix=SUFFIX
  override the usual backup suffix 

  --verbose
  print the name of each directory as it is created 

  -V, --version-control=WORD
  override the usual version control 

  --help
  display the help and exit
  So if we have a file called foo and we want to install it in
  /usr/local/bin/, and we want it to have the following permission line:
  -rwxr-x---, then we want it to belong to the group ftp, then
  we do like this: 

  install -m 750 foo -g ftp /usr/local/bin/  

  We could also use:
  install -m u+rwx,g+rx foo -g ftp /usr/local/bin/
  Which would produce the same permission line.
  The install command is good to use if you ever do anything that
  needs to be installed to the system, in a proper way.
 -------------------------------------------------------------------------------
 ipchains
  ipchains is a firewall/wrapper that has ALOT of argument,
  it's one of those huge commands, do: man ipchains
  for more information on this command.
 -------------------------------------------------------------------------------
 ispell
  Interactive Spell check, this is a useful little command,
  it's basic usage is: ispell <file>
  It has the following commands:
  R       Replace the misspelled word completely.
  Space   Accept the word this time only.
  A       Accept the word for the rest of this session.
  I       Accept the word, and put it in your private dictionary.
  U       Accept and add lowercase version to private dictionary.
  0-n     Replace with one of the suggested words.
  L       Look up words in system dictionary.
  X       Write the rest of this file, ignoring misspellings,
  and start next file.
  Q       Quit immediately.  Asks for confirmation.
  Leaves file unchanged.
  !       Shell escape.
  ^L      Redraw screen.
  ^Z      Suspend program.
  ?       Show the help screen.
  Just run it on a file and test it for your self.
 -------------------------------------------------------------------------------
 kill
  kill is a very powerful command that can (if you're root)
  kill any running process no the system.
  it works as: kill -<signal> <PID>
  Pid is short for Process ID, which you get with the `ps` command. 

  The signals can be any of the following: 

  POSIX signals:
  Signal     Value     Action   Comment
  ----------------------------------------------------------------------
  SIGHUP        1        A     Hangup detected on controlling terminal
  or death of controlling process
  SIGINT        2        A     Interrupt from keyboard
  SIGQUIT       3        C     Quit from keyboard
  SIGILL        4        C     Illegal Instruction
  SIGABRT       6        C     Abort signal from abort(3)
  SIGFPE        8        C     Floating point exception
  SIGKILL       9       AEF    Kill signal
  SIGSEGV      11        C     Invalid memory reference
  SIGPIPE      13        A     Broken pipe: write to pipe with no readers
  SIGALRM      14        A     Timer signal from alarm(2)
  SIGTERM      15        A     Termination signal
  SIGUSR1   30,10,16     A     User-defined signal 1
  SIGUSR2   31,12,17     A     User-defined signal 2
  SIGCHLD   20,17,18     B     Child stopped or terminated
  SIGCONT   19,18,25           Continue if stopped
  SIGSTOP   17,19,23    DEF    Stop process
  SIGTSTP   18,20,24     D     Stop typed at tty
  SIGTTIN   21,21,26     D     tty input for background process
  SIGTTOU   22,22,27     D     tty output for background process
  Non-POSIX signals:
  Signal       Value     Action   Comment
  ----------------------------------------------------------------------
  SIGBUS      10,7,10      C     Bus error (bad memory access)
  SIGPOLL                  A     Pollable event (Sys V). Synonym of SIGIO
  SIGPROF     27,27,29     A     Profiling timer expired
  SIGSYS      12,-,12      C     Bad argument to routine (SVID)
  SIGTRAP        5         C     Trace/breakpoint trap
  SIGURG      16,23,21     B     Urgent condition on socket (4.2 BSD)
  SIGVTALRM   26,26,28     A     Virtual alarm clock (4.2 BSD)
  SIGXCPU     24,24,30     C     CPU time limit exceeded (4.2 BSD)
  SIGXFSZ     25,25,31     C     File size limit exceeded (4.2 BSD)
  Other signals:
  Signal       Value     Action   Comment
  -------------------------------------------------------------------
  SIGIOT         6         C     IOT trap. A synonym for SIGABRT
  SIGEMT       7,-,7
  SIGSTKFLT    -,16,-      A     Stack fault on coprocessor
  SIGIO       23,29,22     A     I/O now possible (4.2 BSD)
  SIGCLD       -,-,18            A synonym for SIGCHLD
  SIGPWR      29,30,19     A     Power failure (System V)
  SIGINFO      29,-,-            A synonym for SIGPWR
  SIGLOST      -,-,-       A     File lock lost
  SIGWINCH    28,28,20     B     Window resize signal (4.3 BSD, Sun)
  SIGUNUSED    -,31,-      A     Unused signal (will be SIGSYS) 

  When you use the kill you can either use the numeric code, as
  say that we have a PID 1234 that we wanna kill, then we can either
  do: kill -9 1234 or we can do: kill -KILL 1234
  So you don't have to include that leading SIG in the signals
  when you use them by name.
 -------------------------------------------------------------------------------
 killall
  killall is the same as kill but kills processes by name,
  As say that you have 10 processes running all named: httpd
  and you wanna kill them all in one command.
  Then: killall -9 httpd  would be the way to go about it.
 -------------------------------------------------------------------------------
 lastlog
  lastlog is a command that shows you a list of the users and when
  they last logged in, from what host and on which port.
  lastlog can be used with the following arguments: 

  -u	username
  -t	number of days
  so if I wanna check if a user named 'user' has logged in during
  the last 50 days I do: lastlog -u user -t 50
 -------------------------------------------------------------------------------
 ldconfig
  ldconfig updates the list of directory's in where library's can be
  found as /lib and /usr/lib, if you wanna add a directory to this you
  can add them in /etc/ld.so.conf
  By just typing `ldconfig` you will update this, but it can
  also be executed with more arguments, for more info on this
  command do: man ldconfig
  Just note that this is not really a command that you will use
  every day.
 -------------------------------------------------------------------------------
 ldd
  ldd can check what librarys a dynamicly executable file needs.
  and it can have the following switches:
  --help                  print this help and exit
  --version               print version information and exit
  -d, --data-relocs       process data relocations
  -r, --function-relocs   process data and function relocations
  -v, --verbose           print all information
  It works like this: 

  ldd <file> 

  Example: 

  ldd /sbin/ifconfig
 -------------------------------------------------------------------------------
 less
  less is more then more ..... ummmm
  less works a bit like cat but it will stop at each screen and you
  can scroll up and down in the file to view it's contents,
  it works basicly like this: less <textfile>
  Do a: less --help
  For a full index of it's commands, and note that you get out
  of less by pressing the letter 'q'.
 -------------------------------------------------------------------------------
 lilo
  lilo is the LInux LOader, and is on most distros the default
  boot loader, with lilo you can rewrite your boot sector and
  everything that involves your booting or switching between
  several installed operating systems, lilo's configuration file
  is /etc/lilo.conf
  for more info about lilo and what lilo can do do: man lilo
 -------------------------------------------------------------------------------
 ln
  link, with ln you can link any file, this is essential to *nix
  as, say that you have a config file that needs to be in the same
  dir as it's program but you want it in /etc with all the other
  configuration files, then you can link it to /etc so the link
  appears in /etc and works just like the real file.
  Usually ln is used to set symbolic links (sym links) where you
  can see the difference of the link and the file and you can remove
  the link without it affecting the real file.
  A symbolic link is set in this way: ln -s file link
 -------------------------------------------------------------------------------
 lndir
  link directory, about the same as ln but links directory's,
  see the: man lndir
 -------------------------------------------------------------------------------
 loadkeys
  loadkeys, basicly works like: loadkeys /usr/lib/kbd/keymaps/<keymap>
  but also has some arguments (that I never used), if you want
  more info: man loadkeys
 -------------------------------------------------------------------------------
 locate
  locate can locate any file that's read into a database,
  you update this database if you as root type: updatedb
  locate works basicly like: locate <whatever-you-wanna-find>
  but can be executed with alot of arguments, do: locate --help
  or for more info: man locate
 -------------------------------------------------------------------------------
 logout
  logout does what it says, it logs you off the shell.
 -------------------------------------------------------------------------------
 lpq
  line printer que, checks if you have any printer jobs on que. 

  -------------------------------------------------------------------------------
 lpr
  line printer, has alot of commands, but basicly works as: lpr <file>
  to print a file, the lpr command has alot of arguments,
  do: man lpr for more info. 

  -------------------------------------------------------------------------------
 lprm
  line printer remove, removes any qued jobs (lpq) by there entry number.
 -------------------------------------------------------------------------------