Evernote Cheat Sheet

 

Search – Notebooks

Include
notebo­ok:­My­Notes
Multi-word
notebo­ok:­”My Notes­”
This must be the 1st search term.

Search – Tags

Include
tag:M­yTag
Exclude
-tag:­MyTag
Wildcard
tag:M­yTag*
Multi-­words
tag:”My Tag
Tagged notes
tag:*
Untagged notes
-tag:*
For wildcard, the asterisk must be at the end. There is no way to combine wildcard with multi-­words.

Search – To Do

Any
todo:*
Unchecked
todo:false
Checked
todo:true

Search – Source

Email
source­:ma­il.smtp
Web page
source­:we­b.clip
Mobile
source­:mo­bile.*
Applic­ation
source­:app.*
Delicious
source­:de­licious

Search – Resource

Audio
resour­ce:­audio/*
Image
resour­ce:­image/*
GIF
resour­ce:­ima­ge/gif
Ink
resour­ce:­app­lic­ati­on/­vnd.ev­ern­ote.ink
PDF
resour­ce:­app­lic­ati­on/pdf
Handwr­iting
recoTy­pe:­han­dwr­itten
To do
todo:*
Encryption
encryp­tion:
Attachment
attach­men­t:true
Tag
tag:*

Search – General

Include
MyText
Exclude
MyText
Wildcard
MyTe*
Multiple words
My Text
This will search the body, title, and tag attrib­utes.

Search – Other

Title
intitl­e:­MyText
OR search
any:M­yText “­Other text”

Search – Dates

Created date
create­d:day
Updated date
update­d:day
Day terms
Date
20120704
Date and time
201207­04T­090000
Date and time (GMT)
201207­04T­090000Z
Today
day
Yesterday
day-1
30 days ago
day-30
This week
week
Last week
week-1
This month
month
Last month
month-1
This year
year
Last year
year-1
Exam­ples
Created yesterday (only)
-creat­ed:day create­d:day-1
Updated on July 4th, 2012
update­d:2­0120704
Updated last year (only)
-updat­ed:year update­d:y­ear-1
Older than a year
-creat­ed:year
Will match any note that has a timestamp that is equal to, or more recent than, the provided datetime.

EN – Mac Global Shortcuts

New note
⌃⌘N
Paste to Evernote
⌃⌘V
Clip rectangle
⌃⌘C
Find in Evernote
⌃⌘E
You must have the Evernote Helper running for these to work.

EN – PC Global Shortcuts

New note
Ctrl+Alt+N
Find in Evernote
Win+Sh­ift+F
Capture screen
Win+Pr­int­S­creen
Copy selection
Win+A
Past clipboard
Ctrl+Alt+V
Evernote must be running in the system tray.

EN – Limits

Account Limits
Tags
100,000
Notebooks
250
Saved searches
100
Notes
100,000
Upload limit/­month
1 GB (or 60 MB)
Linked notebooks
100
Shared notebooks
250
Note limits
Tags
100
Resources
1,000
Size
50MB (or 25MB)
Field limits
Tag name
100 chars
Note title
255 chars
Notebook name
100 chars
Saved search name
100 chars

VI Editor Cheatsheet

Intro

The default editor that comes with the UNIX operating system is called vi (visual editor). [Alternate editors for UNIX environments include vim, nano, pico and emacs, a product of GNU.] The UNIX vi editor is a full screen editor and has two modes of operation:

  1. Command mode commands which cause action to be taken on the file, and
  2. Insert mode in which entered text is inserted into the file.

In the command mode, every character typed is a command that does something to the text file being edited; a character typed in the command mode may even cause the vi editor to enter the insert mode. In the insert mode, every character typed is added to the text in the file; pressing the <Esc> (Escape) key turns off the Insert mode.

  • The vi editor opens in this mode, and it only understands commands
  • In this mode, you can, move the cursor and cut, copy, paste the text
  • This mode also saves the changes you have made to the file
  • Commands are case sensitive. You should use the right letter case.

    While there are a number of vi commands, just a handful of these is usually sufficient for beginning vi users. To assist such users, here’s a list that contains a sampling of basic vi commands. The most basic and useful commands are marked with an asterisk (* or star) in the tables below. With practice, these commands should become automatic.

To Start vi

To use vi on a file, type in vi filename. If the file named filename exists, then the first page (or screen) of the file will be displayed; if the file does not exist, then an empty file and screen are created into which you may enter text.
* vi filename edit filename starting at line 1
vi -r filename recover filename that was being edited when system crashed

To Exit vi

Usually the new or modified file is saved when you leave vi. However, it is also possible to quit vi without saving the file.
Note: The cursor moves to bottom of screen whenever a colon (:) is typed. This type of command is completed by hitting the <Return> (or <Enter>) key.
* 😡<Return> quit vi, writing out modified file to file named in original invocation
:wq<Return> quit vi, writing out modified file to file named in original invocation
:q<Return> quit (or exit) vi
* :q!<Return> quit vi even though latest changes have not been saved for this vi call

Moving the Cursor

Unlike many of the PC and MacIntosh editors, the mouse does not move the cursor within the vi editor screen (or window). You must use the the key commands listed below. On some UNIX platforms, the arrow keys may be used as well; however, since vi was designed with the Qwerty keyboard (containing no arrow keys) in mind, the arrow keys sometimes produce strange effects in vi and should be avoided.
If you go back and forth between a PC environment and a UNIX environment, you may find that this dissimilarity in methods for cursor movement is the most frustrating difference between the two.
In the table below, the symbol ^ before a letter means that the <Ctrl> key should be held down while the letter key is pressed.
* j or <Return>
[or down-arrow]
move cursor down one line
* k [or up-arrow] move cursor up one line
* h or <Backspace>
[or left-arrow]
move cursor left one character
* l or <Space>
[or right-arrow]
move cursor right one character
* 0 (zero) move cursor to start of current line (the one with the cursor)
* $ move cursor to end of current line
w move cursor to beginning of next word
b move cursor back to beginning of preceding word
:0<Return> or 1G move cursor to first line in file
:n<Return> or nG move cursor to line n
:$<Return> or G move cursor to last line in file

Screen Manipulation

The following commands allow the vi editor screen (or window) to move up or down several lines and to be refreshed.
^f move forward one screen
^b move backward one screen
^d move down (forward) one half screen
^u move up (back) one half screen
^l redraws the screen
^r redraws the screen, removing deleted lines

Adding, Changing, and Deleting Text

Unlike PC editors, you cannot replace or delete text by highlighting it with the mouse. Instead use the commands in the following tables.
Perhaps the most important command is the one that allows you to back up and undo your last action. Unfortunately, this command acts like a toggle, undoing and redoing your most recent action. You cannot go back more than one step.
* u UNDO WHATEVER YOU JUST DID; a simple toggle
The main purpose of an editor is to create, add, or modify text for a file.

Inserting or Adding Text

The following commands allow you to insert and add text. Each of these commands puts the vi editor into insert mode; thus, the <Esc> key must be pressed to terminate the entry of text and to put the vi editor back into command mode.
* i insert text before cursor, until <Esc> hit
I insert text at beginning of current line, until <Esc> hit
* a append text after cursor, until <Esc> hit
A append text to end of current line, until <Esc> hit
* o open and put text in a new line below current line, until <Esc> hit
* O open and put text in a new line above current line, until <Esc> hit

Changing Text

The following commands allow you to modify text.
* r replace single character under cursor (no <Esc> needed)
R replace characters, starting with current cursor position, until <Esc> hit
cw change the current word with new text,
starting with the character under cursor, until <Esc> hit
cNw change N words beginning with character under cursor, until <Esc> hit;
e.g., c5w changes 5 words
C change (replace) the characters in the current line, until <Esc> hit
cc change (replace) the entire current line, stopping when <Esc> is hit
Ncc or cNc change (replace) the next N lines, starting with the current line,
stopping when <Esc> is hit

Deleting Text

The following commands allow you to delete text.
* x delete single character under cursor
Nx delete N characters, starting with character under cursor
dw
4dd
delete the single word beginning with character under cursor
Delete 4 words
dNw delete N words beginning with character under cursor;
e.g., d5w deletes 5 words
D delete the remainder of the line, starting with current cursor position
* dd
3dd
delete entire current line
Delete 3 lines
Ndd or dNd delete N lines, beginning with the current line;
e.g., 5dd deletes 5 lines

Cutting and Pasting Text

The following commands allow you to copy and paste text.
yy copy (yank, cut) the current line into the buffer
Nyy or yNy copy (yank, cut) the next N lines, including the current line, into the buffer
p put (paste) the line(s) in the buffer into the text after the current line

Searching Text

A common occurrence in text editing is to replace one word or phase by another. To locate instances of particular sets of characters (or strings), use the following commands.
/string search forward for occurrence of string in text
?string search backward for occurrence of string in text
n move to next occurrence of search string
N move to next occurrence of search string in opposite direction

Determining Line Numbers

Being able to determine the line number of the current line or the total number of lines in the file being edited is sometimes useful.
:.= returns line number of current line at bottom of screen
:= returns the total number of lines at bottom of screen
^g provides the current line number, along with the total number of lines,
in the file at the bottom of the screen

Saving and Reading Files

These commands permit you to input and output files other than the named file with which you are currently working.

:r filename<Return> read file named filename and insert after current line
(the line with cursor)
:w<Return> write current contents to file named in original vi call
:w newfile<Return> write current contents to a new file named newfile
:12,35w smallfile<Return> write the contents of the lines numbered 12 through 35 to a new file named smallfile
:w! prevfile<Return> write current contents over a pre-existing file named prevfile

VI CHEATSHEET

Quitting

: x Exit, saving changes
:q Exit as long as there have been no changes
ZZ Exit and save changes if any have been made
:q! Exit and ignore any changes

Inserting Text

i Insert before cursor
I Insert before line
a Append after cursor
A Append after line
o Open a new line after current line
O Open a new line before current line
r Replace one character
R Replace many characters

Motion

h Move left
j Move down
k Move up
l Move right
w Move to next word
W Move to next blank delimited word
b Move to the beginning of the word
B Move to the beginning of blank delimted word
e Move to the end of the word
E Move to the end of Blank delimited word
( Move a sentence back
) Move a sentence forward
{ Move a paragraph back
} Move a paragraph forward
0 Move to the begining of the line
$ Move to the end of the line
1G Move to the first line of the file
G Move to the last line of the file
nG Move to nth line of the file
:n Move to nth line of the file
fc Move forward to c
Fc Move back to c
H Move to top of screen
M Move to middle of screen
L Move to botton of screen
% Move to associated ( ), { }, [ ]
:0 Move to the beginning of the file
:$ Move to the end of the file
[ctrl] + d go down half a screen
[ctrl] + u go up half a screen
[ctrl] + f go forward a screen
[ctrl] + b go back a screen

Deleting Text

x Delete character to the right of cursor
X Delete character to the left of cursor
D Delete to the end of the line
dd Delete current line
:d Delete current line
Yanking Text
yy Yank the current line
:y Yank the current line

Changing text

C Change to the end of the line
cc Change the whole line
guu lowercase line
gUU uppercase line
~ Toggle upp and lower case

Putting text

p Put after the position or after the line
P Put before the poition or before the line

Markers

mc Set marker c on this line
`c Go to beginning of marker c line.
‘c Go to first non-blank character of marker c line.

Search for strings

/string Search forward for string
?string Search back for string
n Search for next instance of string
N Search for previous instance of string

Replace

:s/pat­ter­n/s­tri­ng/­flags Replace pattern with string according to flags.
g Flag – Replace all occurences of pattern
c Flag – Confirm replaces.

Modes

Vi has two modes insertion mode and command mode. The editor begins in command mode, where the cursor movement and text deletion and pasting occur. Insertion mode begins upon entering an insertion or change command. [ESC] returns the editor to command mode (where you can quit, for example by typing :q!). Most commands execute as soon as you type them except for “­col­on” commands which execute when you press the ruturn key.

HTML character cheat sheet

HTML Character Entities
&#32; Space
&#33;!Exclam­ation mark
&#34;Quotation mark
&#35;#Pound / hash
&#36;$Dollar sign
&#37;%Percent sign
&#38;&Ampersand
&#39;`Apostrophe
&#40;(Left bracket
&#41;)Right bracket
&#42;*Asterisk
&#43;+Plus
&#44;,Comma
&#45;Hyphen
&#46;.Period
&#47;/Forward Slash
&#48;0Zero
&#49;1One
&#50;2Two
&#51;3Three
&#52;4Four
&#53;5Five
&#54;6Six
&#55;7Seven
&#56;8Eight
&#57;9Nine
&#58;:Colon
&#59;;Semicolon
&#60;<Less than
&#61;=Equals
&#62;>Greater than
&#63;?Question mark
&#64;@“­At” symbol
&#65;AUpper case A
&#66;BUpper case B
&#67;CUpper case C
&#68;DUpper case D
&#69;EUpper case E
&#70;FUpper case F
&#71;GUpper case G
&#72;HUpper case H
&#73;IUpper case I
&#74;JUpper case J
&#75;KUpper case K
&#76;LUpper case L
&#77;MUpper case M
&#78;NUpper case N
&#79;OUpper case O
&#80;PUpper case P
&#81;QUpper case Q
&#82;RUpper case R
&#83;SUpper case S
&#84;TUpper case T
&#85;UUpper case U
&#86;VUpper case V
&#87;WUpper case W
&#88;XUpper case X
&#89;YUpper case Y
&#90;ZUpper case Z
&#91;[Left square bracket
&#92;\Backslash
&#93;]Right square bracket
&#94;^Caret
&#95;_Underscore
&#96;`Single quote / backtick
HTML Character Entities
&#97;aLower case a
&#98;bLower case b
&#99;cLower case c
&#100;dLower case d
&#101;eLower case e
&#102;fLower case f
&#103;gLower case g
&#104;hLower case h
&#105;iLower case i
&#106;jLower case j
&#107;kLower case k
&#108;lLower case l
&#109;mLower case m
&#110;nLower case n
&#111;oLower case o
&#112;pLower case p
&#113;qLower case q
&#114;rLower case r
&#115;sLower case s
&#116;tLower case t
&#117;uLower case u
&#118;vLower case v
&#119;wLower case w
&#120;xLower case x
&#121;yLower case y
&#122;zLower case z
&#123;{Left curly brace
&#124;|Pipe
&#125;}Right curly brace
&#126;~Tilde
&#127; Delete
&#160; Non-br­eaking space
&#161;¡Inverted exclam­ation mark
&#162;¢Cent symbol
&#163;£Pound symbol
&#164;¤Currency symbol
&#165;¥Yen symbol
&#166;¦Broken pipe
&#167;§Section symbol
&#168;¨Umlaut
&#169;©Copyright
&#170;ªFeminine ordinal
&#171;«Double­-left arrow
&#172;¬“­Not­” symbol
&#173; Soft hyphen
&#174;®Registered
&#175;¯Overline
&#176;°Degree symbol
&#177;±Plus or minus
&#178;²Squared
&#179;³Cubed
&#180;´Acute accent
&#181;µMicro symbol
&#182;Paragraph symbol
&#183;·Middle dot
&#184;¸Cedilla
&#185;¹Supers­cript 1
&#186;ºMasculine ordinal
&#187;»Double­-right arrow
&#188;¼One quarter
&#189;½One half
HTML Character Entities
&#190;¾Three quarters
&#191;¿Inverted question mark
&#192;ÀA with grave
&#193;ÁA with acute
&#194;ÂA with circumflex
&#195;ÃA with tilde
&#196;ÄA with umlaut
&#197;ÅA with ring
&#198;ÆAE
&#199;ÇC with cedilla
&#200;ÈE with grave
&#201;ÉE with acute
&#202;ÊE with circumflex
&#203;ËE with umlaut
&#204;ÌI with grave
&#205;ÍI with acute
&#206;ÎI with circumflex
&#207;ÏI with umlaut
&#208;ÐETH
&#209;ÑN with tilde
&#210;ÒO with grave
&#211;ÓO with acute
&#212;ÔO with circumflex
&#213;ÕO with tilde
&#214;ÖO with umlaut
&#215;×Multiply symbol
&#216;ØO with slash
&#217;ÙU with grave
&#218;ÚU with acute
&#219;ÛU with circumflex
&#220;ÜU with umlaut
&#221;ÝY with acute
&#222;ÞTHORN
&#223;ßSharp S
&#224;àa with grave
&#225;áa with acute
&#226;âa with circumflex
&#227;ãa with tilde
&#228;äa with umlaut
&#229;åa with ring
&#230;æae
&#231;çc with cedilla
&#232;èe with grave
&#233;ée with acute
&#234;êe with circumflex
&#235;ëe with umlaut
&#236;ìi with grave
&#237;íi with acute
&#238;îi with circumflex
&#239;ïi with umlaut
&#240;ðETH
&#241;ñn with tilde
&#242;òo with grave
&#243;óo with acute
&#244;ôo with circumflex
&#245;õo with tilde
&#246;öo with umlaut
&#247;÷Divide symbol
&#248;øo with slash
&#249;ùu with grave
&#250;úu with acute
&#251;ûu with circumflex
&#252;üu with umlaut
&#253;ýy with acute
&#254;þTHORN
&#255;ÿy with umlaut

Keyboard – ASCII and UTF

Info

ASCII stands for American Standard Code for Information Interchange. It’s a 7-bit character code where every single bit represents a unique character. On this webpage you will find 8 bits, 256 characters, according to ISO 8859-1 and Microsoft® Windows Latin-1 increased characters, which is available in certain programs such as Microsoft Word.

How to keyboard imput using ALT+0000

How to generate each character with keyboard. Alt codes work on computers running any of Microsoft’s Windows operating systems.

  1. Find the Alt Code you need from the alt code tables below.
  2. Make sure that “Number Lock” is switched on. There should be a light on your keyboard indicating this. (If not, press the “Number Lock” key at the top left of the numeric keypad.)
  3. Hold down the “Alt” key to the left of the space bar and key the code on the numeric keypad.
  4. Don’t release the “Alt” key until after you’ve typed the alt code. When you release it you should see the special character you include.

Instructions for entering Alt Codes on a lap topEven if you have a laptop or a keyboard with no numeric keypad – you can still use alt codes.

  1. Look for a “function” or “fn” key normally near the bottom left of the keyboard.
  2. Look for a button with “num lock” written in the same colour which is usually near the top right of the keyboard.
  3. While holding “function” press and relase “num lock“.
  4. Enter alt codes using the method above but to enter the actual numeric alt code use the keys with numbers in the same colour as the function (fn) key. Normally “U” has 4 on it for example.
  5. Switch “num lock” off in the same way as you switched it on to continue using your keyboard normally.

ASCII codes

ASCII control characters (character code 0-31)

The first 32 characters in the ASCII-table are unprintable control codes and are used to control peripherals such as printers.

DEC OCT HEX BIN Symbol HTML Number HTML Name Description
0 000 00 00000000 NUL &#000;   Null char
1 001 01 00000001 SOH &#001;   Start of Heading
2 002 02 00000010 STX &#002;   Start of Text
3 003 03 00000011 ETX &#003;   End of Text
4 004 04 00000100 EOT &#004;   End of Transmission
5 005 05 00000101 ENQ &#005;   Enquiry
6 006 06 00000110 ACK &#006;   Acknowledgment
7 007 07 00000111 BEL &#007;   Bell
8 010 08 00001000 BS &#008;   Back Space
9 011 09 00001001 HT &#009;   Horizontal Tab
10 012 0A 00001010 LF &#010;   Line Feed
11 013 0B 00001011 VT &#011;   Vertical Tab
12 014 0C 00001100 FF &#012;   Form Feed
13 015 0D 00001101 CR &#013;   Carriage Return
14 016 0E 00001110 SO &#014;   Shift Out / X-On
15 017 0F 00001111 SI &#015;   Shift In / X-Off
16 020 10 00010000 DLE &#016;   Data Line Escape
17 021 11 00010001 DC1 &#017;   Device Control 1 (oft. XON)
18 022 12 00010010 DC2 &#018;   Device Control 2
19 023 13 00010011 DC3 &#019;   Device Control 3 (oft. XOFF)
20 024 14 00010100 DC4 &#020;   Device Control 4
21 025 15 00010101 NAK &#021;   Negative Acknowledgement
22 026 16 00010110 SYN &#022;   Synchronous Idle
23 027 17 00010111 ETB &#023;   End of Transmit Block
24 030 18 00011000 CAN &#024;   Cancel
25 031 19 00011001 EM &#025;   End of Medium
26 032 1A 00011010 SUB &#026;   Substitute
27 033 1B 00011011 ESC &#027;   Escape
28 034 1C 00011100 FS &#028;   File Separator
29 035 1D 00011101 GS &#029;   Group Separator
30 036 1E 00011110 RS &#030;   Record Separator
31 037 1F 00011111 US &#031;   Unit Separator

ASCII printable characters (character code 32-127)

Codes 32-127 are common for all the different variations of the ASCII table, they are called printable characters, represent letters, digits, punctuation marks, and a few miscellaneous symbols. You will find almost every character on your keyboard. Character 127 represents the command DEL.

DEC OCT HEX BIN Symbol HTML Number ( or ALT+) HTML Name Description
32 040 20 00100000   &#32;   Space
33 041 21 00100001 ! &#33;   Exclamation mark
34 042 22 00100010 &#34; &quot; Double quotes (or speech marks)
35 043 23 00100011 # &#35;   Number
36 044 24 00100100 $ &#36;   Dollar
37 045 25 00100101 % &#37;   Percentsign
38 046 26 00100110 & &#38; &amp; Ampersand
39 047 27 00100111 &#39;   Single quote
40 050 28 00101000 ( &#40;   Open parenthesis (or open bracket)
41 051 29 00101001 ) &#41;   Close parenthesis (or close bracket)
42 052 2A 00101010 * &#42;   Asterisk
43 053 2B 00101011 + &#43;   Plus
44 054 2C 00101100 , &#44;   Comma
45 055 2D 00101101 &#45;   Hyphen
46 056 2E 00101110 . &#46;   Period, dot or full stop
47 057 2F 00101111 / &#47;   Slash or divide
48 060 30 00110000 0 &#48;   Zero
49 061 31 00110001 1 &#49;   One
50 062 32 00110010 2 &#50;   Two
51 063 33 00110011 3 &#51;   Three
52 064 34 00110100 4 &#52;   Four
53 065 35 00110101 5 &#53;   Five
54 066 36 00110110 6 &#54;   Six
55 067 37 00110111 7 &#55;   Seven
56 070 38 00111000 8 &#56;   Eight
57 071 39 00111001 9 &#57;   Nine
58 072 3A 00111010 : &#58;   Colon
59 073 3B 00111011 ; &#59;   Semicolon
60 074 3C 00111100 < &#60; &lt; Less than (or open angled bracket)
61 075 3D 00111101 = &#61;   Equals
62 076 3E 00111110 > &#62; &gt; Greater than (or close angled bracket)
63 077 3F 00111111 ? &#63;   Question mark
64 100 40 01000000 @ &#64;   At symbol
65 101 41 01000001 A &#65;   Uppercase A
66 102 42 01000010 B &#66;   Uppercase B
67 103 43 01000011 C &#67;   Uppercase C
68 104 44 01000100 D &#68;   Uppercase D
69 105 45 01000101 E &#69;   Uppercase E
70 106 46 01000110 F &#70;   Uppercase F
71 107 47 01000111 G &#71;   Uppercase G
72 110 48 01001000 H &#72;   Uppercase H
73 111 49 01001001 I &#73;   Uppercase I
74 112 4A 01001010 J &#74;   Uppercase J
75 113 4B 01001011 K &#75;   Uppercase K
76 114 4C 01001100 L &#76;   Uppercase L
77 115 4D 01001101 M &#77;   Uppercase M
78 116 4E 01001110 N &#78;   Uppercase N
79 117 4F 01001111 O &#79;   Uppercase O
80 120 50 01010000 P &#80;   Uppercase P
81 121 51 01010001 Q &#81;   Uppercase Q
82 122 52 01010010 R &#82;   Uppercase R
83 123 53 01010011 S &#83;   Uppercase S
84 124 54 01010100 T &#84;   Uppercase T
85 125 55 01010101 U &#85;   Uppercase U
86 126 56 01010110 V &#86;   Uppercase V
87 127 57 01010111 W &#87;   Uppercase W
88 130 58 01011000 X &#88;   Uppercase X
89 131 59 01011001 Y &#89;   Uppercase Y
90 132 5A 01011010 Z &#90;   Uppercase Z
91 133 5B 01011011 [ &#91;   Opening bracket
92 134 5C 01011100 \ &#92;   Backslash
93 135 5D 01011101 ] &#93;   Closing bracket
94 136 5E 01011110 ^ &#94;   Caret – circumflex
95 137 5F 01011111 _ &#95;   Underscore
96 140 60 01100000 ` &#96;   Grave accent
97 141 61 01100001 a &#97;   Lowercase a
98 142 62 01100010 b &#98;   Lowercase b
99 143 63 01100011 c &#99;   Lowercase c
100 144 64 01100100 d &#100;   Lowercase d
101 145 65 01100101 e &#101;   Lowercase e
102 146 66 01100110 f &#102;   Lowercase f
103 147 67 01100111 g &#103;   Lowercase g
104 150 68 01101000 h &#104;   Lowercase h
105 151 69 01101001 i &#105;   Lowercase i
106 152 6A 01101010 j &#106;   Lowercase j
107 153 6B 01101011 k &#107;   Lowercase k
108 154 6C 01101100 l &#108;   Lowercase l
109 155 6D 01101101 m &#109;   Lowercase m
110 156 6E 01101110 n &#110;   Lowercase n
111 157 6F 01101111 o &#111;   Lowercase o
112 160 70 01110000 p &#112;   Lowercase p
113 161 71 01110001 q &#113;   Lowercase q
114 162 72 01110010 r &#114;   Lowercase r
115 163 73 01110011 s &#115;   Lowercase s
116 164 74 01110100 t &#116;   Lowercase t
117 165 75 01110101 u &#117;   Lowercase u
118 166 76 01110110 v &#118;   Lowercase v
119 167 77 01110111 w &#119;   Lowercase w
120 170 78 01111000 x &#120;   Lowercase x
121 171 79 01111001 y &#121;   Lowercase y
122 172 7A 01111010 z &#122;   Lowercase z
123 173 7B 01111011 { &#123;   Opening brace
124 174 7C 01111100 | &#124;   Vertical bar
125 175 7D 01111101 } &#125;   Closing brace
126 176 7E 01111110 ~ &#126;   Equivalency sign – tilde
127 177 7F 01111111   &#127;   Delete

The extended ASCII codes (character code 128-255)

There are several different variations of the 8-bit ASCII table. The table below is according to ISO 8859-1, also called ISO Latin-1. Codes 128-159 contain the Microsoft® Windows Latin-1 extended characters.

DEC OCT HEX BIN Symbol HTML Number HTML Name Description
128 200 80 10000000 &#128; &euro; Euro sign
129 201 81 10000001        
130 202 82 10000010 &#130; &sbquo; Single low-9 quotation mark
131 203 83 10000011 ƒ &#131; &fnof; Latin small letter f with hook
132 204 84 10000100 &#132; &bdquo; Double low-9 quotation mark
133 205 85 10000101 &#133; &hellip; Horizontal ellipsis
134 206 86 10000110 &#134; &dagger; Dagger
135 207 87 10000111 &#135; &Dagger; Double dagger
136 210 88 10001000 ˆ &#136; &circ; Modifier letter circumflex accent
137 211 89 10001001 &#137; &permil; Per mille sign
138 212 8A 10001010 Š &#138; &Scaron; Latin capital letter S with caron
139 213 8B 10001011 &#139; &lsaquo; Single left-pointing angle quotation
140 214 8C 10001100 Π&#140; &OElig; Latin capital ligature OE
141 215 8D 10001101        
142 216 8E 10001110 Ž &#142;   Latin captial letter Z with caron
143 217 8F 10001111        
144 220 90 10010000        
145 221 91 10010001 &#145; &lsquo; Left single quotation mark
146 222 92 10010010 &#146; &rsquo; Right single quotation mark
147 223 93 10010011 &#147; &ldquo; Left double quotation mark
148 224 94 10010100 &#148; &rdquo; Right double quotation mark
149 225 95 10010101 &#149; &bull; Bullet
150 226 96 10010110 &#150; &ndash; En dash
151 227 97 10010111 &#151; &mdash; Em dash
152 230 98 10011000 ˜ &#152; &tilde; Small tilde
153 231 99 10011001 &#153; &trade; Trade mark sign
154 232 9A 10011010 š &#154; &scaron; Latin small letter S with caron
155 233 9B 10011011 &#155; &rsaquo; Single right-pointing angle quotation mark
156 234 9C 10011100 œ &#156; &oelig; Latin small ligature oe
157 235 9D 10011101        
158 236 9E 10011110 ž &#158;   Latin small letter z with caron
159 237 9F 10011111 Ÿ &#159; &Yuml; Latin capital letter Y with diaeresis
160 240 A0 10100000   &#160; &nbsp; Non-breaking space
161 241 A1 10100001 ¡ &#161; &iexcl; Inverted exclamation mark
162 242 A2 10100010 ¢ &#162; &cent; Cent sign
163 243 A3 10100011 £ &#163; &pound; Pound sign
164 244 A4 10100100 ¤ &#164; &curren; Currency sign
165 245 A5 10100101 ¥ &#165; &yen; Yen sign
166 246 A6 10100110 ¦ &#166; &brvbar; Pipe, Broken vertical bar
167 247 A7 10100111 § &#167; &sect; Section sign
168 250 A8 10101000 ¨ &#168; &uml; Spacing diaeresis – umlaut
169 251 A9 10101001 © &#169; &copy; Copyright sign
170 252 AA 10101010 ª &#170; &ordf; Feminine ordinal indicator
171 253 AB 10101011 « &#171; &laquo; Left double angle quotes
172 254 AC 10101100 ¬ &#172; &not; Not sign
173 255 AD 10101101   &#173; &shy; Soft hyphen
174 256 AE 10101110 ® &#174; &reg; Registered trade mark sign
175 257 AF 10101111 ¯ &#175; &macr; Spacing macron – overline
176 260 B0 10110000 ° &#176; &deg; Degree sign
177 261 B1 10110001 ± &#177; &plusmn; Plus-or-minus sign
178 262 B2 10110010 ² &#178; &sup2; Superscript two – squared
179 263 B3 10110011 ³ &#179; &sup3; Superscript three – cubed
180 264 B4 10110100 ´ &#180; &acute; Acute accent – spacing acute
181 265 B5 10110101 µ &#181; &micro; Micro sign
182 266 B6 10110110 &#182; &para; Pilcrow sign – paragraph sign
183 267 B7 10110111 · &#183; &middot; Middle dot – Georgian comma
184 270 B8 10111000 ¸ &#184; &cedil; Spacing cedilla
185 271 B9 10111001 ¹ &#185; &sup1; Superscript one
186 272 BA 10111010 º &#186; &ordm; Masculine ordinal indicator
187 273 BB 10111011 » &#187; &raquo; Right double angle quotes
188 274 BC 10111100 ¼ &#188; &frac14; Fraction one quarter
189 275 BD 10111101 ½ &#189; &frac12; Fraction one half
190 276 BE 10111110 ¾ &#190; &frac34; Fraction three quarters
191 277 BF 10111111 ¿ &#191; &iquest; Inverted question mark
192 300 C0 11000000 À &#192; &Agrave; Latin capital letter A with grave
193 301 C1 11000001 Á &#193; &Aacute; Latin capital letter A with acute
194 302 C2 11000010 Â &#194; &Acirc; Latin capital letter A with circumflex
195 303 C3 11000011 Ã &#195; &Atilde; Latin capital letter A with tilde
196 304 C4 11000100 Ä &#196; &Auml; Latin capital letter A with diaeresis
197 305 C5 11000101 Å &#197; &Aring; Latin capital letter A with ring above
198 306 C6 11000110 Æ &#198; &AElig; Latin capital letter AE
199 307 C7 11000111 Ç &#199; &Ccedil; Latin capital letter C with cedilla
200 310 C8 11001000 È &#200; &Egrave; Latin capital letter E with grave
201 311 C9 11001001 É &#201; &Eacute; Latin capital letter E with acute
202 312 CA 11001010 Ê &#202; &Ecirc; Latin capital letter E with circumflex
203 313 CB 11001011 Ë &#203; &Euml; Latin capital letter E with diaeresis
204 314 CC 11001100 Ì &#204; &Igrave; Latin capital letter I with grave
205 315 CD 11001101 Í &#205; &Iacute; Latin capital letter I with acute
206 316 CE 11001110 Î &#206; &Icirc; Latin capital letter I with circumflex
207 317 CF 11001111 Ï &#207; &Iuml; Latin capital letter I with diaeresis
208 320 D0 11010000 Ð &#208; &ETH; Latin capital letter ETH
209 321 D1 11010001 Ñ &#209; &Ntilde; Latin capital letter N with tilde
210 322 D2 11010010 Ò &#210; &Ograve; Latin capital letter O with grave
211 323 D3 11010011 Ó &#211; &Oacute; Latin capital letter O with acute
212 324 D4 11010100 Ô &#212; &Ocirc; Latin capital letter O with circumflex
213 325 D5 11010101 Õ &#213; &Otilde; Latin capital letter O with tilde
214 326 D6 11010110 Ö &#214; &Ouml; Latin capital letter O with diaeresis
215 327 D7 11010111 × &#215; &times; Multiplication sign
216 330 D8 11011000 Ø &#216; &Oslash; Latin capital letter O with slash
217 331 D9 11011001 Ù &#217; &Ugrave; Latin capital letter U with grave
218 332 DA 11011010 Ú &#218; &Uacute; Latin capital letter U with acute
219 333 DB 11011011 Û &#219; &Ucirc; Latin capital letter U with circumflex
220 334 DC 11011100 Ü &#220; &Uuml; Latin capital letter U with diaeresis
221 335 DD 11011101 Ý &#221; &Yacute; Latin capital letter Y with acute
222 336 DE 11011110 Þ &#222; &THORN; Latin capital letter THORN
223 337 DF 11011111 ß &#223; &szlig; Latin small letter sharp s – ess-zed
224 340 E0 11100000 à &#224; &agrave; Latin small letter a with grave
225 341 E1 11100001 á &#225; &aacute; Latin small letter a with acute
226 342 E2 11100010 â &#226; &acirc; Latin small letter a with circumflex
227 343 E3 11100011 ã &#227; &atilde; Latin small letter a with tilde
228 344 E4 11100100 ä &#228; &auml; Latin small letter a with diaeresis
229 345 E5 11100101 å &#229; &aring; Latin small letter a with ring above
230 346 E6 11100110 æ &#230; &aelig; Latin small letter ae
231 347 E7 11100111 ç &#231; &ccedil; Latin small letter c with cedilla
232 350 E8 11101000 è &#232; &egrave; Latin small letter e with grave
233 351 E9 11101001 é &#233; &eacute; Latin small letter e with acute
234 352 EA 11101010 ê &#234; &ecirc; Latin small letter e with circumflex
235 353 EB 11101011 ë &#235; &euml; Latin small letter e with diaeresis
236 354 EC 11101100 ì &#236; &igrave; Latin small letter i with grave
237 355 ED 11101101 í &#237; &iacute; Latin small letter i with acute
238 356 EE 11101110 î &#238; &icirc; Latin small letter i with circumflex
239 357 EF 11101111 ï &#239; &iuml; Latin small letter i with diaeresis
240 360 F0 11110000 ð &#240; &eth; Latin small letter eth
241 361 F1 11110001 ñ &#241; &ntilde; Latin small letter n with tilde
242 362 F2 11110010 ò &#242; &ograve; Latin small letter o with grave
243 363 F3 11110011 ó &#243; &oacute; Latin small letter o with acute
244 364 F4 11110100 ô &#244; &ocirc; Latin small letter o with circumflex
245 365 F5 11110101 õ &#245; &otilde; Latin small letter o with tilde
246 366 F6 11110110 ö &#246; &ouml; Latin small letter o with diaeresis
247 367 F7 11110111 ÷ &#247; &divide; Division sign
248 370 F8 11111000 ø &#248; &oslash; Latin small letter o with slash
249 371 F9 11111001 ù &#249; &ugrave; Latin small letter u with grave
250 372 FA 11111010 ú &#250; &uacute; Latin small letter u with acute
251 373 FB 11111011 û &#251; &ucirc; Latin small letter u with circumflex
252 374 FC 11111100 ü &#252; &uuml; Latin small letter u with diaeresis
253 375 FD 11111101 ý &#253; &yacute; Latin small letter y with acute
254 376 FE 11111110 þ &#254; &thorn; Latin small letter thorn
255 377 FF 11111111 ÿ &#255; &yuml; Latin small letter y with diaeresis

 

Uppercase Lowercase
Alt Codes Symbol Description Alt Codes Symbol Description
Alt 0192 À A grave Alt 0224 à a grave
Alt 0193 Á A acute Alt 0225 á a acute
Alt 0194 Â A circumflex Alt 0226 â a circumflex
Alt 0195 Ã A tilde Alt 0227 ã a tilde
Alt 0196 Ä A umlaut Alt 0228 ä a umlaut
Alt 0199 Ç C cedilla Alt 0231 ç c cedilla
Alt 0200 È E grave Alt 0232 è e grave
Alt 0201 É E acute Alt 0233 é e acute
Alt 0202 Ê E circumflex Alt 0234 ê e circumflex
Alt 0203 Ë E umlaut Alt 0235 ë e umlaut
Alt 0204 Ì I grave Alt 0236 ì i grave
Alt 0205 Í I acute Alt 0237 í i acute
Alt 0206 Î I circumflex Alt 0238 î i circumflex
Alt 0207 Ï I umlaut Alt 0239 ï i umlaut
Alt 165 Ñ N tilde Alt 164 ñ n tilde
Alt 0210 Ò O grave Alt 0242 ò o grave
Alt 0211 Ó O acute Alt 0243 ó o acute
Alt 0212 Ô O circumflex Alt 0244 ô o circumflex
Alt 0213 Õ O tilde Alt 0245 õ o tilde
Alt 0214 Ö O umlaut Alt 0246 ö o umlaut
Alt 0138 Š S caron Alt 0154 š s caron
Alt 0218 Ú U acute Alt 0249 ù u grave
Alt 0219 Û U circumflex Alt 0250 ú u acute
Alt 0220 Ü U umlaut Alt 0251 û u circumflex
Alt 0217 Ù U grave Alt 0252 ü u umlaut
Alt 0221 Ý Y acute Alt 0253 ý y acute
Alt 0159 Ÿ Y umlaut Alt 0255 ÿ y umlaut
Alt 0142 Ž Z caron Alt 0158 ž z caron

ALT Codes for letters with accents

Uppercase Lowercase
Alt Codes Symbol Description Alt Codes Symbol Description
Alt 0192 À A grave Alt 0224 à a grave
Alt 0193 Á A acute Alt 0225 á a acute
Alt 0194 Â A circumflex Alt 0226 â a circumflex
Alt 0195 Ã A tilde Alt 0227 ã a tilde
Alt 0196 Ä A umlaut Alt 0228 ä a umlaut
Alt 0199 Ç C cedilla Alt 0231 ç c cedilla
Alt 0200 È E grave Alt 0232 è e grave
Alt 0201 É E acute Alt 0233 é e acute
Alt 0202 Ê E circumflex Alt 0234 ê e circumflex
Alt 0203 Ë E umlaut Alt 0235 ë e umlaut
Alt 0204 Ì I grave Alt 0236 ì i grave
Alt 0205 Í I acute Alt 0237 í i acute
Alt 0206 Î I circumflex Alt 0238 î i circumflex
Alt 0207 Ï I umlaut Alt 0239 ï i umlaut
Alt 165 Ñ N tilde Alt 164 ñ n tilde
Alt 0210 Ò O grave Alt 0242 ò o grave
Alt 0211 Ó O acute Alt 0243 ó o acute
Alt 0212 Ô O circumflex Alt 0244 ô o circumflex
Alt 0213 Õ O tilde Alt 0245 õ o tilde
Alt 0214 Ö O umlaut Alt 0246 ö o umlaut
Alt 0138 Š S caron Alt 0154 š s caron
Alt 0218 Ú U acute Alt 0249 ù u grave
Alt 0219 Û U circumflex Alt 0250 ú u acute
Alt 0220 Ü U umlaut Alt 0251 û u circumflex
Alt 0217 Ù U grave Alt 0252 ü u umlaut
Alt 0221 Ý Y acute Alt 0253 ý y acute
Alt 0159 Ÿ Y umlaut Alt 0255 ÿ y umlaut
Alt 0142 Ž Z caron Alt 0158 ž z caron

ALT Codes for Currency Symbols

Alt Code Symbol Description
Alt 0164 ¤ Currency
Alt 156 £ Pound
Alt 0128 Euro
Alt 36 $ Dollar Sign
Alt 155 ¢ Cent
Alt 157 ¥ Yen
Alt 158 Peseta
Alt 159 ƒ Frank / Gulder

ALT Codes for Mathematical Symbols

Alt Code Symbol Description
Alt 0169 © Copyright
Alt 169 ® Registered symbol
Alt 0153 Trademark

ALT Codes for Punctuation

Interrogetary and Exclamatory
Alt Code Symbol Description
Alt 33 ! Exclamation Mark
Alt 19 Double Exclamation
Alt 173 ¡ Inverted exclamation mark
Alt 63 ? Question Mark
Alt 168 ¿ inverted question mark
Alt Codes for Parenthesis
Alt Code Symbol Description
Alt 40 ( Open Bracket
Alt 41 ) Close Bracked
Alt 91 [ Open Square Bracket
Alt 93 ] Close Square Bracket
Alt 123 { Open curley bracket
Alt 125 } Close curley bracket
Alt Codes for Editing
Alt Code Symbol Description
Alt 28 Tab Marker
Alt 21 § Paragraph
Alt 20 Carriage Return
Alt 0134 dagger / obelos
Alt 0135 double dagger / diesis
Reported Speech / Quotation
Alt Code Symbol Description
Alt 34 Quotation Mark
Alt 0139 quotation mark
Alt 0155 quotation mark
Alt 0145 curly single open quote
Alt 0146 curly single close quote
Alt 0147 curly double open quote
Alt 0148 curly double close quote
Alt 174 « Quotation Mark
Alt 175 » Quotation Mark
Alt 0130 curly single quote
Alt 0132 low curly doublequote
Alt Codes for Abbreviation
Alt Code Symbol Description
Alt 39 Apostraphe
Alt 96 ` Angled Apostraphe
Alt 38 & Ampersand
Alt 64 @ At Symbol
Alt Codes for General Punctuation
Alt 58 : Colon
Alt 59 ; Semi-Colon
Alt 44 , Comma
Alt 46 . Full Stop / Period
Alt 32   Space
Alt 255   Alternative Space
Alt 0133 dot dot dot / ellipsis
Alt 95 _ Underscore
Alt 0175 ¯ overscore
Alt 124 | Bar
Alt 126 ~ Tilda/Squiggle
Alt 0168 ¨ diaresis
Alt 45 Dash or Hyphen
Alt 0151 Longer Dash or Hyphen
Alt 22 Long Hyphon
Alt 42 * Asterisk
Alt 47 / Slash
Alt 92 \ Back Slash
1º and 1ª mean 1st in some languages
Alt 166 ª a superscript
Alt 167 º o superscript
Archaic Punctuation Alt Codes
Alt 0183 · interpunct

Alt Codes for entering Bullets and Symbols

Alt Code Symbol Description
Alt 1 White Smiley
Alt 2 Black Smiley
Alt 3 Heart
Alt 4 Diamond
Alt 5 Club
Alt 6 Spade
Alt 7 Bullet 1
Alt 8 Bullet 2
Alt 9 Bullet 3
Alt 10 Bullet 4
Alt 11 Male Sign
Alt 12 Female Sign
Alt 13 Quaver
Alt 14 Joined Quavers
Alt 16 Play Forward
Alt 17 Play Reverse
Alt 254 Stop
Alt 30  
Alt 31  
Alt 23  
Alt 24 Up Arrow
Alt 25 Down Arrow
Alt 26 Right Arrow
Alt 27 Left Arrow
Alt 0129   Undefined – Normally generates a box
Alt 15 ??
127 ??
Alt 18 ??
Alt 29 ??

Alt Codes for entering Mathematical Symbols

ALT Codes for Mathematical Symbols
Alt Code Symbol Description
Alt 48 – 57 0 – 9 zero to nine
Alt Codes for Basic Operators
Alt Code Symbol Description
Alt 43 + Plus Sign
Alt 45 Minus Sign
Alt 0215 × Multiplication Sign
Alt 0247 ÷ Obelus / Division ign
Alt Codes for Pers
Alt Code Symbol Description
Alt 37 % Percentage Sign
Alt 0137 Per mille (per thousand)
Alt Codes for Bracketing
Alt Code Symbol Description
Alt 40 ( Open Bracket
Alt 41 ) Close Bracked
Alt Codes for Degree of Accuracy
Alt Code Symbol Description
Alt 241 ± Plus or Minus
Alt Codes for Fractions
Alt Code Symbol Description
Alt 47 / Fraction seperator
Alt 0188 ¼ Quarter
Alt 0189 ½ Half
Alt 0190 ¾ Three quarters
Alt 46 . Decimal Point
Alt Codes for Equality
Alt Code Symbol Description
Alt 240 Exactly Identical
Alt 61 = Equals
Alt 247 Approximately equal
Alt Codes for Inequality
Alt Code Symbol Description
Alt 60 < Less Than
Alt 62 > Greater Than
Alt 242 Greater than or equal
Alt 243 Less than or equal
Alt Codes for Powers
Alt Code Symbol Description
Alt 251 Square Root
Alt 252 Power n
Alt 0185 ¹ To the power of 1
Alt 0178 ² squared
Alt 0179 ³ cubed
Angles and Trigonometric Alt Codes
Alt Code Symbol Description
Alt 227 π Pi
Alt 248 ° Degree sign
 
General Mathematical Symbols
Alt Code Symbol Description
Alt 35 # Number
Alt 236 Infinity
Alt 230 µ Micro
Alt 228 Σ Sum
Alt 239 ??
Integration / Integral Sign
Alt Code Symbol Description
Alt 244 Top half
Alt 245 Bottom Half

ALT Codes for Programming

Alt Code Symbol Description
Alt 0166 ¦ Unix Pipeline
Alt 40 ( Open Bracket
Alt 41 ) Close Bracked
Alt 94 ^ To the power of
Alt 60 < Less Than
Alt 62 > Greater Than
Alt 61 = Equals
Alt 42 * Multiply
Alt 47 / Divide or Slash
Alt 92 \ Back Slash
Alt 35 # Hash
Alt 40 ( Open Bracket
Alt 41 ) Close Bracked
Alt 64 @ At Symbol
Alt 91 [ Open Square Bracket
Alt 93 ] Close Square Bracket
Alt 123 { Open curley bracket
Alt 125 } Close curley bracket
Alt 42 * Wildcard and Multiply

ALT Codes for “Extra” Letters

Uppercase Lowercase
Alt Code Symbol Description Alt Code Symbol Description
Alt 0229 å Aa Alt 0197 Å aa
Alt 0140 Œ Oethel Alt 0156 œ oethel
Alt 0254 þ Thorn Alt 0222 Þ thorn
Alt 0216 Ø Slashed O Alt 0248 ø Slashed o
Alt 0198 Æ AE ligature Alt 0230 æ ae ligature
Alt 165 Ñ N tilde Alt 164 ñ n tilde
Alt 0223 ß Eszett
Alt 0208 Ð Eth Alt 0240 ð eth

ALT Codes for Arrow Symbols

Alt Code Symbol
Filled Arrows
Alt 16
Alt 17
Alt 254
Alt 30
Alt 31
Line Arrows
Alt 23
Alt 24
Alt 25
Alt 26
Alt 27

Selected Custom Characters

Cyrillic chars

Words Desr
А́ а́
Ъ́ ъ́
О́ о́
У́ у́
е́ Е́
И́ и́
Ю́ ю́
Я́ я́
right accent
А̀ а̀
Ъ̀ ъ̀
О̀ о̀
У̀ у̀
Ѐ ѐ
Ѝ ѝ
ю̀ ю̀
Я̀ я̀
left accent
Й̀ ѝ̀, Й́, ѝ́ complex
Ѝ ѝ
Й й
 
   

Special Chars

Words Desr
Trade Mark;  Alt Code 0153
© Copyright; Alt Code 169;
   
   
   

Greek chars

The Greek alphabet

Greek name of letter


Symbol

English equivalent

Pronunciation

Alpha

Α

A

A as in smart

Beta

Β

B

V as in very

Gamma

Γ

G

Between Y as in yes and G as in go, but with no hard ‘G’ sound – more of a soft ‘H’ followed by the ‘Y’ sound in yes

Delta

Δ

D

Th as in the 

Epsilon

Ε

E

E as in very

Zeta

Ζ

Z

Z as in zoo

Eta

Η

E

Ee as in bee

Theta

Θ

Th

Th as in think

Iota

Ι

I

Ee as in bee or I as in bitter or sit

Kappa

Κ

K

K as in look

Lamda

Λ

L

L as in log

Mu

Μ

M

M as in man

Nu

Ν

N

N as in not

Xi

Ξ

X

X as in box

Omicron

Ο

O

O as in box

Pi

Π

P

P as in top, but softer and close to ‘B’

Rho

Ρ

R, Rh

a rolled R

Sigma

Σ

S

S as in sap with a hint of Sh as in sugar

Tau

Τ

T

T as in lot, but softer and close to ‘D’

Upsilon

Υ

U

Same as eta – Ee as in bee

Phi

Φ

Ph

Ph as in photo

Chi

Χ

Kh

Ch as in the scottish ‘loch’ but softer – not a hard sound

Psi

Ψ

Ps

Ps as in upside

Omega

Ω

M

like omicron – O as in box – or longer ‘O’ sound like the vowel sound in oar

Alpha Α α
Beta Β β
Gamma Γ γ
Delta Δ δ
Epsilon Ε ε
Zeta Ζ ζ
Eta Η η
Theta Θ θ ϑ
Iota Ι ι
Kappa Κ κ
Lambda Λ λ
Mu Μ μ
Nu Ν ν
Xi Ξ ξ
Omicron Ο ο
Pi Π π
Rho Ρ ρ
Sigma Σ σ ς
Tau Τ τ
Upsilon Υ υ
Phi Φ φ
Chi Χ χ
Psi Ψ ψ
Omega Ω ω
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

Europeand Special Chars

Accents and diacritical marks
Non-standard characters signs that change the sound of letters and words

Many western languages contain words with letters whose sound is determined by these accents and diacritical marks. The effects are different depending on the language; here are the names and examples of the more common marks and non-standard characters. Usage of these accents and marks is not restricted to the letters shown in the examples.

  • é – accent acute
  • è – accent grave
  • ê – circumflex
  • ë – umlaut or diaerisis
  • ç – cedilla
  • ñ – tilde
  • ø – streg
  • ð – eth (capital form Ð)
  • å – bolle
  • æ – ligature
  • œ – ligature
  • ē – macron
  • č – háček
  • ŭ – crescent

All in one table below:

¡¿
ÄäÀàÁáÂâÃãÅåǍǎĄąĂăÆæĀā
ÇçĆćĈĉČč
ĎđĐďð
ÈèÉéÊêËëĚěĘęĖėĒē
ĜĝĢģĞğ
Ĥĥ
ÌìÍíÎîÏïıĪīĮį
Ĵĵ
Ķķ
ĹĺĻļŁłĽľ
ÑñŃńŇňŅņ
ÖöÒòÓóÔôÕõŐőØøŒœ
ŔŕŘř
ẞߌśŜŝŞşŠšȘș
ŤťŢţÞþȚț
ÜüÙùÚúÛûŰűŨũŲųŮůŪū
Ŵŵ
ÝýŸÿŶŷ
ŹźŽžŻż
   

 

   

 

   

 

 

Info:
Croatian letter – đ and Đ.
Hungarian letters – őŐ and űŰ
Swedish letters –  Åå
Polish letters – ŻżĄąĘę
Romainan letters –  Ţţ Ăă
Dannish letters –  Ææ
Icelandic letters –  ð, þ, and Þ
French letters – Œ
Slovakia letters Ľľ   and Czeck letters Ůů
 Turkish letters – Ğğ and ı
Baltic package –  Āā, Ėė, Ēē, Īī, Įį, Ņņ and Ūū
Others –  ď, ģ, ì, Ï, ì, Ø and ť
T and S with comma and cedilla
Bulgarian letters – АБВГДЕЖЗИЙКЛМНОПРСТУФХЦШЩЪЮЯ
Greek letters –

 

 

Links

Online Keyboard (Multilingual) – Greek sample
https://www.lexilogos.com/keyboard/greek_modern.htm

Online Keyboard (Multilingual) – Bulgarian sample:
https://www.lexilogos.com/keyboard/bulgarian.htm

Linux Commands

History

How to clear the terminal command history

Clearing typed commands from terminal history: By default, up to the last 500 command lines a user types in the terminal window are saved into a hidden .bash_history file. The previously typed commands can be readily accessed by using the up and down arrow keys. This makes it easy to retrieve and reuse your recently used commands. However, maybe you want to clear the terminal command history list and start fresh? This simple tutorial explains the process of viewing and then optionally clearing the terminal history. Viewing the complete terminal command history: To view the complete history of commands typed in the terminal “for the logged in user”, open the terminal and type history How to clear the terminal command line history:

  1. Login with the user account whose terminal history you plan to clear
  2. Open a terminal window and type
    history -c
  3. Repeat the process if necessary for each user account

How to delete a single command from history on a Linux

  I‘m working in Ubuntu bash terminal application and remotely on a RHEL server in cloud platform. I typed the wrong and dangerous command. I no longer wish to remember dangerous command in the history file. How can I remove or delete a single command from bash history file?   You can use the history command to clear all history or selected command line.

How do I view history with line number?

Simply type the history command:

$ history

Sample outputs:

How to delete a single command number 1013 from history

The syntax is:

## Delete the bash history entry at offset OFFSET ##history -d offset   history -d number history -d 1013

Verify it:

$ history

How do I delete all the history?

The syntax is:
history -c

Tip: Control bash history like a pro

First, you can increase your bash history size by appending the following config option in ~/.bashrc file:


Save and close the file.

Where to find more information about history command?

    You can read bash man page by typing the following command:  
$ man bash  
Or simply type the following command:  
$ help history      

FIND

Find command examples

Let us try out some examples.

Finding files and printing their full name

You wish to find out all *.c (all c source code) files located under /home directory, enter: $ find /home -name “*.c” You would like to find httpd.conf file location: $ find / -name httpd.conf

Finding all files owned by a user

Find out all files owned by user USER: # find / -user USER Find out all *.sh owned by user USER: # find / -user USER -name “*.sh”

Finding files according to date and time

Files not accessed in a time period – It is useful to find out files that have or have not been accessed within a specified number of days. Following command prints all files not accessed in the last 7 days: # find /home -atime +7

  • -atime +7: All files that were last accessed more than 7 days ago
  • -atime 7: All files that were last accessed exactly 7 days ago
  • -atime -7: All files that were last accessed less than7 days ago

Finding files modified within a specified time – Display list of all files in /home directory that were not last modified less than then days ago. # find /home -mtime -7

Finding newer (more recently) modified files

Use -newer option to find out if file was modified more recently than given file. # find /etc/apache-perl -newer /etc/apache-perl/httpd.conf

Finding the most recent version of file

It is common practice before modifying the file is copied to somewhere in system. For example whenever I modify web server httpd.conf file I first make backup. Now I don’t remember whether I had modified the /backup.conf/httpd.conf or /etc/apache-perl/httpd.conf. You can use the find command as follows (tip you can also use ls -l command): find / -name httpd.conf -newer /etc/apache-perl/httpd.conf

Locate command

The locate command is often the simplest and quickest way to find the locations of files and directories on Linux and other Unix-like operating systems.   For example, the following command uses the star wildcard to display all files on the system that have the .c filename extension: # locate “*.c”    

Rename

Linux Rename File Command

  I‘m a new Linux user. How do I rename a file called resumezzz.pdf to resume.pdf using Linux bash command prompt?   You need to use the mv command. It is used to rename and move files and directories. The general syntax is as follows:  

mv old-file-name new-file-name mv [options] old-file-name new-file-name mv file1 file2

  In this example, the following command would rename a file called resumezzz.pdf to resume.pdf. Open a command-line terminal (select Applications > Accessories > Terminal), and then type:  

mv resumezzz.pdf resume.pdf

  If resumezzz.pdf is located in /home/user/docs/files directory, type:  

cd /home/user/docs/files mv resumezzz.pdf resume.pdf

  OR  

mv /home/user/docs/files/resumezzz.pdf /home/user/docs/files/resume.pdf

  Use the ls command to view files:

ls -l file1 ls -l file1 file2 ls -l /home/user/docs/files/*.pdf ls -l *.pdf   =============== NAMING

Linux rename a file syntax

In short, to rename a file:  

mv file1 file2

  You can get verbose output i.e. mv command can explain what is being done using the following syntax:  

mv -v file1 file2

  Sample outputs: `file1′ -> `file2′   ========   REMOVE

EXECUTABLE:   There are a couple ways. If you just want to do this temporarily, you can remove the execute bit from the file:

$ chmod -x /etc/init.d/varnish

Then re-add it when appropriate:

$ chmod +x /etc/init.d/varnish

The “official” way in Ubuntu (as well as in Debian and other Debian derivatives), though, is to use the update-rc.d command:

$ update-rc.d varnish disable    

Search and Find

SEARCH AND FIND files in locations

find / -xdev -name vip_monitor,sh  953  find / -xdev -name vip_monitor.sh  954  mv /root/vip_monitor.sh /root/vip_monitor.sh_

USE OF SH FILE AND EXTENSIONS

Run .bin file in Linux / UNIX

Change the permission of the file you downloaded to be executable. Type the following command: $ chmod +x file.bin Start the installation process or run .bin file. Type the following command: ./file.bin For example if .bin file name is application.bin. Type the following commands: $ chmod +x application.bin $ ./application.bin   Another example for Java Linux self extracting binary file: $ chmod +x jre-1_5_0-linux-i586.bin $ ./jre-1_5_0-linux-i586.bin

OR $ sh jre-1_5_0-linux-i586.bin    

Correct way to disable init-scripts to start at boottime on Debian

  In several articles and forums I see people telling the way of removing the init-script on a Debian system would be:   update-rc.d -f init-script-name remove   The more appropriate way is to disable the init-script from running at boottime:   update-rc.d init-script-name stop levels   In this way you prevent that in case you upgrade the package a new init-script will be created with the defaults. If the init-script is written with the defaults the init-script might start the process again at boot-up. If you disabled the init-script from running at boottime the init-script would not be recreated or overwritten with the init-script in the update.

Colour of Colour

 

Colour names

Color Names Supported by All Browsers

All modern browsers support the following 140 color names (click on a color name, or a hex value, to view the color as the background-color along with different text colors):

HEX codes

RGB codes

Shades

Names

Yellow Color Names

yellow color names

Orange Color Names

orange color names

Red Color Names

red color names

Pink Color Names

pink color names

Violet Color Names

violet color names

Blue Color Names

blue color names

Green Color Names

green color names

Brown Color Names

brown color names

Gray Color Names

Gray Color Names

System Commands

System Commands

shutdown bring the system down shutdown -h now -h = Halt or poweroff after shutdown
shutdown -r now -r : Reboot after shutdown
shutdown -r -F now -F : Force fsck after reboot.
halt stop the system. halt
reboot reboot the system. reboot
init init 1 #change to single usermode
uptime Tell how long the system has been running. uptime
runlevel find the previous and current system runlevel. runlevel
printenv print all or part of environment printenv
env run a program in a modified environment env
hostname show or set the system’s host name hostname – show the system’s host name
hostname NEWHOSTNASME – set the system’s host name
uname print system information uname -a – print all information
locale Get locale-specific information. locale
locale -a |grep -i ja <- -a : –all-locales

Process Management

ps report a snapshot of the current processes. ps aux |grep httpd ← Check httpd rocess
ps aux | grep XXX | awk ‘{print $2}’ | xargs kill -9
ps auxwf
ps auxwf |grep XXX
pgrep look up processes based on name and other attributes pgrep -f ‘bash’
pgrep -lf ‘bash’ ← output with process name
pgrep -f ‘bash’ | xargs kill
pstree display a tree of processes pstree -a
pidof find the process ID of a running program pidof httpd
/bin/kill $(/sbin/pidof qmail-popup)
kill send a signal to a process kill -9 PID ← (-9 or -KILL = force-quit)
pkill signal processes based on name and other attributes pkill -f ‘bash’
pkill -u user1
pkill java
pkill -f jar
killall kill processes by name killall vi
killall -i vi ← -i = Interactively
killall -HUP kterm
killproc
lsof list open files lsof -i
lsof -i -P ← no port names
lsof -i :80,443 ← Which process is using Port 80,443
Ctrl + C Stop running process
Ctrl + Z Suspend running process Move Running Process to Background
1. ctrl + z
2. jobs
3. bg
4. disown %JOBID
jobs The first form lists the active jobs. jobs -l ← List job
fg Resume jobspec in the foreground
bg Resume each suspended job jobspec in the background
nohup run a command immune to hangups, with output to a non-tty nohup command.sh &
disown disown %jobid
nice run a program with modified scheduling priority nice -n 19 test.sh
nice -n 19 ionice -c 3 CMD
nice -n 19 ionice -c 2 -n 7 COMMAND
renice alter priority of running processes renice 19 -p PID
you can check the nice whith “top” or “ps alx”.
ionice sets or gets process io scheduling class and priority ionice -p PID ← check
ionice -c 3 -p PID
nice -n 19 ionice -c 2 -n 7 COMMAND

Schedule

crontab maintain crontab files crontab -l ← -l = list user’s crontab
crontab -u USER -l
crontab -e ← -e = edit user’s crontab
crontab -u USER -e
at queue jobs for later execution echo “/sbin/shutdown -h now” |at 21:00 02/30/2009
at -t 200902302100
atq lists the user’s pending jobs atq
atrm delete jobs for later execution atrm JOBID
watch execute a program periodically, showing output fullscreen watch ntpq -p ← By default, the program is run every 2 seconds
watch -n 1 ntpq -p ← 1 seconds interval
-d : highlight the differences between successive updates

etc

alias Alias with no arguments or with the -p option prints the list of aliases
When arguments are supplied, an alias is defined for each name whose value is given.
alias ← check all alias
alias ls=’ls -la –color=auto’
alias grep=’grep –color’
unalias Remove each name from the list of defined aliases.
If -a is supplied, all alias definitions are removed.
unalias COMMAND
ntpdate set the date and time via NTP ntpdate -b -u IP
-b : Force the time (step mode)
-u : If you are running ntpd, “-u” must be added.
chronyc command-line interface for chronyd chronyc sources
chronyc sources -v
ntpq standard NTP query program ntpq -p
-p : Print a list of the peers known to the server
watch -n 1 ntpq -p
hwclock query and set the hardware clock (RTC) hwclock (-r) ← Read the Hardware Clock and print the time on standard output.
hwclock -w ← Set the Hardware Clock to the current System Time.
hwclock -s ← Set the System Time from the Hardware Clock.
man an interface to the on-line reference manuals man COMMAND
whatis display manual page descriptions whatis KEYWORD
whatis cat
whatis vi
history GNU History Library history |less
history 5 ← lists only the last 5 lines.
HISTSIZE=1000
HISTTIMEFORMAT=“%Y/%m/%d %H:%M:%S ”
which locate a command which ls
time time a simple command or give resource usage time sleep 5
strace trace system calls and signals strace -t php test.php
strace -t -o test.txt php test.php
-t : each line of the trace with the time of day.
ltrace A library call tracer lltrace -o test.txt wget http://example.com/
ltrace -p PID
ltrace -p 3365
script make typescript of terminal session script -afq $LOG

Files and Directories Commands

File Commands

ls list directory contents ls -ltrh ← -r : reverse order while sorting
-h : with -l, print sizes in human readable format
ls -ltrh |less
cp copy files and directories cp -p SRC DES
cp -pi /etc/hosts{,.`date ‘+%Y%m%d’`}
cp -pr SRC/ DES/ ← -r,-R : copy directories recursively
cp -p SRC DES ← -f, –force
mv move (rename) files mv file1 file2
mv dir1 dir2
mv file1 file2 file3 DIR
rename renames multiple files rename .htm .html *.htm ← frm .htm to .html
rename “” test *.txt ← add test
rename test “” *.txt ← delete test
rm remove files or directories rm -rf TARGET ← -r,-R : remove directories
touch change file timestamps touch file1
touch -d “2017/10/20 13:00:00” file1
ln make links between files ln -s SRC DES
unlink unlink DES
wc print newline, word, and byte counts for each file wc -l ← -l, –lines = print the line counts
tree list contents of directories in a tree-like format tree -Dpuga /etc
col filter reverse line feeds from input man ifconfig | col -bfx > test.txt

Directory Commands

pwd print name of current/working directory pwd
cd Change the current directory cd ← go to home directory
cd ~/ ← go to home directory
cd .. ← go to parent directory
pushd Adds a directory to the top of the directory stack pushd /var/log
pushd `pwd`
pushd +2 ← check pushd directory with dirs -v and go to No.2
pushd +3 ← check pushd directory with dirs -v and go to No.3
popd Removes entries from the directory stack. popd
dirs displays the list of currently remembered directories. dirs -v
mkdir make directories mkdir -p /tmp/test1/test2/ ← make parent directories as needed
mkdir -m 700 /home/user01/.ssh
rmdir remove empty directories
If you want to delete directory, you must use “rm -r DIR”.
rmdir DIR

Commands to Access File Contents

more file perusal filter for crt viewing
less opposite of more crontab -l |less
view Start in read-only mode.
cat concatenate files and print on the standard output cat /dev/null > access.log
tail output the last part of files tail -n 50 aaa.txt ← output the last N lines
head output the first part of files head -n 100 aaa.txt ← -n , –lines
head * |more ← View the beginning of the file in the directory.
diff compare files line by line diff –suppress-common-lines –side-by-side File1 File2
diff /etc/test{,.`date ‘+%Y%m%d’`}
diff -r dir1 dir2 ← When comparing directories, recursively compare
sdiff side-by-side merge of file differences sdiff -s File1 File2 ← -s : Do not print common lines.
sdiff -s -w 200 File1 File2
colordiff
vimdiff vimdiff file1 file2
vim -d file1 file2

Searching

grep print lines matching a pattern grep WORD FILE |less
grep -Ev “^#|^$” xxx.txt
grep -Ev “^$|^#|^\s*#” file.txt
grep “” ifcfg-eth* ← check filename and contents
grep -r PATTERN –include=”*.txt” DIRECTORY ← -r : recursive
egrep egrep is the same as grep -E egrep “aaa|bbb” file
find , xargs search for files in a directory hierarchy find . -name “*txt*”
find /dir -type f -name “*.log*” -mtime +7 -exec rm -rf {} \;
← “-mtime +7” is 7 days ago

File Compression

tar The GNU version of the tar archiving utility
tar warn the order of target and destination.
tar zcvf test.tar.gz Dir ← Create, Verbose, File
tar ztvf test.tar.gz ← Test, Verbose, File
tar zxvf test.tar.gz ← eXtract, Verbose, File
tar jcvf test.tar.bz2 DIR ← Create, Verbose, File
tar jxvf test.tar.bz2
tar zcvf /tmp/user01.tar.gz user01
tar zxvf user01.tar.gz -C /home
gzip
gunzip
compress or expand files gzip file1
gunzip file1.gz
gzip access_log.2011-[0][5-8]*.txt ←wild card
compress
uncompress
package and compress (archive) files compress file1
uncompress file1.Z
bzip2
bunzip2
bz2cat
a block-sorting file compressor bzip2 file1
bunzip2 file1.gz2
bz2cat file1.gz2
zip
unzip
package and compress (archive) files zip file.zip file1 file2
zip -l file.zip ← -l = list for check
unzip file.zip
unzip -t file.zip ← -t = test
lha lha a file.lzh file1 file2
lha t file.lzh
lha x file.lzh
gzcat gzcat file.gz
gzcat file.Z
zcat zcat file.Z
zless file perusal filter for crt viewing of compressed text zless file.gz
zgrep search possibly compressed files for a regular expression zgrep PATTERN file.gz
zegrep search possibly compressed files for a regular expression zegrep “new” test.txt.gz
zdiff compare compressed files zdiff file1.gz file2.gz

Character

lv a Powerful Multilingual File Viewer / Grep
qkc
nkf Network Kanji Filter
iconv Convert encoding of given files from one encoding to another iconv -f utf-8 -t sjis test.utf8 > test.sjis

User Administration

User

useradd create a new user or update default new user information useradd -u UID -g GROUP -G GROUP1,GROUP2 -s /bin/bash -d HOME_DIR LOGIN
whoami print effective userid whoami
w Show who is logged on and what they are doing. w
who show who is logged on who
who –all
userdel delete a user account and related files userdel -r USER
← (-r, –remove : Files in the user’s home directory will be removed)
vipw edit the password, group, shadow-password or shadow-group file vipw ← edit /etc/passwd
vipw -s ← edit /etc/shadow
passwd change user password echo “password01” | passwd –stdin user01
passwd -S user1 ← check about the status of the password
passwd -l user01 ← Lock the user
passwd -u user01 ← Unlock
chpasswd update passwords in batch mode echo user01:password | chpasswd
echo ‘USER:PASS’ > tmp.txt ; chpasswd < tmp.txt ; rm -f tmp.txt
mkpasswd
chage change user password expiry information chage -l USER ← check
chage -M 90 USER ← the password expires day set 90days
usermod modify a user account usermod -g GROUP USER
usermod -g GROUP -G SUBGROUP USER
usermod -G SUBGROUP USER
usermod -G SUBGROUP1,SUBGROUP2 USER
usermod -G “” USER
usermod -l USER_NAME_NEW USERNAME_OLD ← change username
usermod -d HOME_DIR_NEW USER_NAME ← change home directory
usermod -u UID USER ← change UID
gpasswd gpasswd -a USER sudo ← add USER to GROUP
gpasswd -r USER sudo ← remove USER from GROUP
chsh change login shell chsh -l ← = cat /etc/shells
chsh -s /bin/bash ← changing shell
chsh -s /bin/bash user01
getent get entries from Name Service Switch libraries getent passwd ← you can check LDAP Users
getent group
getent shadow
pam_tally2 The login counter (tallying) module pam_tally2 -u USER ← check
pam_tally2 -u USER –reset ← reset

Group

groups print the groups a user is in groups
groups USERNAME
groupadd create a new group groupadd -g GID GROUP
groupadd -g 1100 dev
groupdel delete a group groupdel GROUP
groupmod change USER’s GID groupmod -g GID GROUP
groupmod -g 1501 testgroup1
find / -gid OLDGID -print ← Check the OLD GID
chgrp change the Group of the file chgrp -R GROUP FILE
vigr edit the password, group, shadow-password or shadow-group file

File Permissions

chmod change file mode bits chmod 777 TARGET
chmod u+s PROGRAM ← add SSUID(Set User ID)
chown change file owner and group chown USER FILE
chown USER:GROUP FILE
chown -R USER:GROUP DIR ← -R : operate on files and directories recursively

Etc

finger user information lookup program finger
finger user01
finger -l user01
su change user ID or become superuser su – ← change root user
sudo su – USER -s /bin/bash
su – user1 -c “ssh user1@192.168.0.xx ls -lh /tmp” >> aaa.txt
sudo execute a command as another user sudo -u USER COMMAND
sudo sh -c ‘echo “test” >> /tmp/test.txt’
id print real and effective user and group IDs id USERNAME
last show listing of last logged in users last
last -5 ← last 5 logged in users
last USER
lastlog reports the most recent login of all users or of a given user lastlog
umask set file mode creation mask umask ← check
umask 022 ← default 666-022=644(rw-r–r–)
umask 002 ← 666-002=664(rw-rw-r–)
umask 000 ← 666-000=666(rw-rw-rw-)

Network

Network

ip show / manipulate routing, devices, policy routing and tunnels ip a ← print ip address
ip addr ← print ip address
ip r ← Show IP Routing
ip route ← Show IP Routing
ss another utility to investigate sockets ss -lt ← TCP Listening Port
ss -ltp ← Process Name with Listening TCP
ss -anu
ifconfig configure a network interface ifconfig ← check ip
ifconfig -a ← -a : display all interfaces
ifconfig eth0 up
ifconfig eth0 down
ifdown take a network interface down ifdown eth0
ifdown eth0 && ifup eth0
ifup bring a network interface up ifup eth0
ifdown eth0 && ifup eth0
route show / manipulate the IP routing table route ← show the IP routing table
route -n ← show the IP routing table
route add -net 192.168.10.0 netmask 255.255.255.0 gw 10.50.0.1
route add -host 192.168.0.100 gw 192.168.1.100
route del -net 192.168.10.0 netmask 255.255.255.0
traceroute print the route packets trace to network host traceroute -n 192.168.0.10
traceroute -T -p 80 192.168.0.10 ← (-T = TCP)
traceroute -U -p 53 192.168.0.10 ← DNS (-U = UDP)
tracepath traces path to a network host discovering MTU along this path tracepath -n 192.168.0.10 ← UDP
*tracepath don’t use TCP.
mtr a network diagnostic tool mtr -rwb xx.xx.xx.xx -c 10 -T -P 443
ethtool Display or change ethernet card settings ethtool eth0
mii-tool view, manipulate media-independent interface status mii-tool eth0
mii-tool -vv eth0
arp manipulate the system ARP cache arp -a ← (-a : Shows the entries of the specified hosts.)
arp -d 192.168.xx.xx ← delete arp
nmcli line tool for controlling NetworkManager

DNS

dig DNS lookup utility dig -h ←help
dig [@global-server] [domain] [q-type]
dig @8.8.8.8 google.com any
dig @8.8.8.8 -x 74.125.235.101
dig google.com mx
dig +trace google.com
dig +trace -x 173.252.120.6
nslookup query Internet name servers interactively nslookup -type=any google.com 8.8.8.8
nslookup google.com 8.8.8.8
nslookup -type=txt google.com
host DNS lookup utility host ← help
host [-t type] [server]
host gmail.com
host x.x.x.x
host -t any google.com 8.8.8.8
host -t mx gmail.com 8.8.8.8
host -t soa gmail.com
-t = specifies the query type
whois client for the whois service whois google.com
nscd name service cache daemon nscd –help
nscd -i hosts ← chache clear
nscd -g ← Print current configuration statistics

Connection

telnet user interface to the TELNET protocol telnet IP PORT
ssh popular OpenSSH SSH client (remote login program) ssh USER@IP
ssh xx.xx.xx.xx “hostname; netstat -rn |grep 10.110.0”
ssh xx.xx.xx.xx sudo /sbin/reboot
scp secure copy (remote file copy program)
the link file copyed as the real file.
scp test.tar.gz user1@192.168.0.10:/tmp
scp -rp /home/user1 user1@192.168.0.10:/home
scp -rp /tmp/test1/ user1@192.168.0.10:/tmp/test2/
rsync popular a fast, versatile, remote (and local) file-copying tool
the link file copyed as the link file.

rsync -avz –delete /home/user1/ /tmp/user1.bk/
← rsync “/” is very important.
rsync -e ssh -avz –delete /home/user1/ user2@192.168.0.2:/home/backup/server1/home/user1/
rsync -e ssh -avz –-bwlimit=1250 FILE user@192.168.0.2:/DIR/ # 1Mbps = 125KBps
ssh-keygen authentication key generation, management and conversion ssh-keygen -t rsa ← generate rsa key pair
ssh-keygen -t rsa -b 4096 -C “” -N “” -f id_rsa
ssh-keygen -R HOST
← Removes all keys belonging to hostname from a known_hosts file.

Check

ping send ICMP ECHO_REQUEST to network hosts ping -c 5 -s 1500 192.168.0.1 ​
ping -i 0.5 192.168.0.1 # -i : interval
nmap Network exploration tool and security / port scanner nmap google.com ← Check TCP
nmap -Pn -sT -p 22 xx.xx.xx.xx ← check Firewall
nmap -Pn -sT -p 443 x.x.x.x -max-rtt-timeout 0.1
nmap -PN -p 22 HOST
nmap -p 443 www.google.com
nc
netcat
Concatenate and redirect sockets nc 192.168.0.10 80 22 ← check TCP
nc -u 192.168.0.100 53 ← check UDP
nc -vz 192.168.0.10 1-1023 ← portscan
nping nping –tcp -p PORT HOST
nping -c 1 –tcp -p PORT HOST
httping measure the latency and throughput of a webserver
http_ping
hping , hping3
fping fping -g 192.168.0.0/24

HTTP

curl popular transfer a URL curl -O http://example.com/images/test.jpg
curl -I http://www.example.com/ ← Only Header
curl -i http://www.example.com/ ← Header and Body
curl –proxy http://proxy.example.com:8080 http://example.com/
wget The non-interactive network downloader. wget http://google.com/
wget -e http_proxy=xx.xx.xx.xx:8080 http://example.com/
wget -e https_proxy=xx.xx.xx.xx:8080 https://example.com/
wget -S –spider http://example.com/ ← Only Header

FTP

ftp ARPANET file transfer program
lftp Sophisticated file transfer program

SNMP

snmpwalk retrieve a subtree of management values using SNMP GETNEXT requests snmpwalk -v 2c -c public localhost sysname
snmpwalk -v 2c -c public localhost .1.3.6.1.2.1
snmpget communicates with a network entity using SNMP GET requests snmpget -v 2c 192.168.0.10 -c public .1.3.6.1.4.1.2021.11.50.0
snmptranslate translate MIB OID names between numeric and textual forms snmptranslate -Tp | less
snmpnetstat display networking status and configuration information from a network entity via SNMP snmpnetstat -v 2c -c public -Can localhost
snmpnetstat -v 2c -c public -Ci localhost
snmpnetstat -v 2c -c public -Cs localhost

Shell Script

Shell

date print or set the system date and time date –date ’10day ago’ +”%Y%m%d” → 20061030
date +”%Y%m%d” → 20061030
date +”%H:%M” → 12:47
cp -p FILE FILE.`date +%Y%m%d`
cp -p FILE FILE.`date -d ‘1day ago’ +%Y%m%d`
tr translate or delete characters
cut remove sections from each line of files echo abcdef |cut -c 3-
echo abcdef |cut -c 2-4
sort sort lines of text files sort -t: +1 -n sample.txt
uniq report or omit repeated lines cat access_log.1 | awk {‘print $4’} |awk -F: {‘print $1$2$3’} | sort |uniq -c
logger a shell command interface to the syslog(3) system log module logger “test test”
basename strip directory and suffix from filenames SHELLNAME=`/usr/bin/basename $0`
SHELLNAME=`/usr/bin/basename $0 .sh`
dirname strip last component from file name DIR=`dirname ${0}`
paste merge lines of files paste -d, test1.txt test2.txt
awk echo “1 2 3 4 5” | awk ‘{ print $1 “,” $3 }’
echo “1 2 : 3 4 : 5” | awk -F: ‘{ print $2 }’
sed sed -e ‘s/xxx/XXX/g’ input.txt > output.txt
sed -i “s/IPADDR=192.168.0.10/IPADDR=192.168.0.11/g” ifcfg-eth0
mail
mailx
send and receive Internet mail
echo test | mail -s “test” -S “smtp=smtp://xx.xx.xx.xx:25” test@example.com
cat test.txt | mail -s “test” -S “smtp=smtp://xx.xx.xx.xx:25” test@example.com
while while : ; do uptime ; sleep 1 ; done
while : ; do uptime >> /tmp/tmp.txt ; sleep 1 ; done
while : ; do ps aux |grep httpd |wc -l ; sleep 1 ; done
for for i in 127.0.0.1 192.168.10.1; do ping -c 2 $i; done
sleep sleep 1
usleep sleep some number of microseconds usleep 1000000 ← 1,000,000 = 1sec
usleep 100000 ← 100,000 = 0.1sec
usleep 10000 ← 10,000 = 0.01sec

Hardware

Hardware

dmesg print or control the kernel ring buffer dmesg
lspci list all PCI devices lspci
nproc print the number of processing units available nproc
grep -c processor /proc/cpuinfo
getconf _NPROCESSORS_ONLN

Module

lsmod show the status of modules in the Linux Kernel lsmod
modinfo show information about a Linux Kernel module modinfo MODULENAME
modinfo bnx2
insmod insert a module into the Linux Kernel
rmmod remove a module from the Linux Kernel
modprobe add and remove modules from the Linux Kernel

Disk Utilities

HDD

du estimate file space usage du -sh *
du -h –max-depth=1
fuser identify processes using files or sockets fuser -mv /mnt/test ← check
fuser -mvk /mnt/test ←(-k : Kill processes)
chroot run command or interactive shell with special root directory
hdparm get/set hard disk parameters
dumpe2fs dump ext2/ext3/ext4 filesystem information
badblocks search a device for bad blocks

Partition

df report file system disk space usage df -h ← (-h : print sizes in human readable format)
df -BG ← Bigabyte Unite
df -BM ← Megabyte Unite
sfdisk partition table manipulator for Linux sfdisk -l ←(-l : List the partitions of a device.)
fdisk manipulate disk partition table fdisk -l ← ( -l : List the partition tables)
fdisk -l /dev/sdb
fdisk -l -o +UUID
gdisk Interactive GUID partition table (GPT) manipulator
parted a partition manipulation program parted -l ← check partitions
parted /dev/mapper/mpath0
lsblk list block devices lsblk
e2label Change the label on an ext2/ext3/ext4 filesystem

Swap

mkswap set up a Linux swap area
swapon enable devices and files for paging and swapping swapon -s ← Check
swapon -a
swapon /dev/xvda3
swapoff disable devices and files for paging and swapping swapoff -a

File Systems

mkfs build a Linux filesystem
#you must umount the device before mkfs.
mkfs -t xfs /dev/sdb1
mkfs -t ext3 /dev/sdb1
mkfs -t ext4 /dev/sdb1
mkfs.xfs mkfs.ext4
mkfs.ext3
#you must umount the device before mkfs. mkfs.ext4 /dev/sdb1
mkfs.ext3 /dev/sdb1
mkfs2fs create an ext2/ext3/ext4 filesyste
#you must umount the device before mkfs.
mke2fs /dev/sdb1 ← ext2
mke2fs -j /dev/sdb1 ← ext3
xfs_info xfs_info /dev/sda1
tune2fs adjust tunable filesystem parameters on ext2/ext3/ext4 filesystems tune2fs -l /dev/mapper/mpath0
← -l : List the contents of the filesystem superblock.
tune2fs -l /dev/mapper/mpath0 |egrep “count|interval”
tune2fs -i 0 -c 0 /dev/mapper/mpath0
← -i : interval, -c : mount count
fsck check and repair a Linux filesystem
you must umount the device before fsck.
for example single usermode and umount.
‘shutdown -r -F now’ is force fsck after reboot.
fsck -p /dev/sda1
← -p : Automatically repair (“preen”) the file system.
fsck.ext4 check and repair a Linux filesystem
e2fsck check a Linux ext2/ext3/ext4 file system
resize2fs ext2/ext3/ext4 file system resizer resize2fs /dev/testvg/lvol0

Data

dd convert and copy a file dd if=/dev/zero of=test_10M bs=1M count=10
dd if=/dev/zero of=test_100M bs=1M count=100
dd if=/dev/zero of=test_1G bs=1M count=1000
dd if=/dev/zero of=temp.bin bs=1 count=0 seek=1G ← sparse file
sync flush file system buffers
shred overwrite a file to hide its contents, and optionally delete it

mount

mount mount a filesystem mount /mnt/test /dev/sda1
mount -o remount /dev/sda1
mount -t cifs //xx.xx.xx.xx/test /mnt/test -o username=guest,password=
umount unmount file systems umount /mnt/test
umount -f /mnt/test
(-f : Force unmount(in case of an unreachable NFS system))
umount -l /mnt/test
(-l : Lazy unmount.Detach the filesystem from the filesystem hierarchy now )

LVM

References : LVM – How to Use LVM in Linux

LVM

lvm LVM2 tools

PV (Physical Volume)

pvs report information about physical volumes
pvdisplay display attributes of a physical volume pvdisplay
pvdisplay -C
pvcreate initialize a disk or partition for use by LVM pvcreate /dev/mapper/mpath0p1
pvcreate /dev/mapper/mpath0p1 /dev/mapper/mpath1p1
pvremove remove a physical volume pvremove /dev/mapper/mpath0p1
pvscan scan all disks for physical volumes

VG (Volume Group)

vgs report information about volume groups vgs -o +vg_tags ← check tag
vgdisplay display attributes of volume groups vgdisplay
vgdisplay -C
vgcreate create a volume group vgcreate vgdata1 /dev/hdb1 /dev/hdc1
vgremove remove a volume group vgremove vg01
vgscan scan all disks for volume groups and rebuild caches
vgchange change attributes of a volume group vgchange -a y ← activate
vgchange -a n ← deactivate
vgchange -a y vg01
vgchange -a n vg01
Check : lvdisplay VGDATA |grep Status
vgchange –addtag $(uname -n) VG_TEST
vgchange –deltag $(uname -n) VG_TEST
vgextend add physical volumes to a volume group vgextend vg01 /dev/hdd1
vgrename rename a volume group vgrename oldvg newvg

LV (Logical Volume)

lvs report information about logical volumes
lvdisplay display attributes of a logical volume lvdisplay
lvdisplay -C
lvdisplay /dev/mapper/VGDATA-lv00
lvcreate create a logical volume in an existing volume group lvcreate -l PENUMBER vgdata
lvcreate -L 150G vgdata
lvremove remove a logical volume lvremove /dev/testvg/lvol0
lvscan scan (all disks) for logical volumes
lvresize resize a logical volume lvresize -L +5G /dev/vg0/home
lvextend extend the size of a logical volume lvextend -L +5G /dev/vg0/home
lvextend -l +100%FREE /dev/mapper/Array00-lv00
lvreduce reduce the size of a logical volume
lvrename rename a logical volume lvrename /dev/vgdata/lvol0 /dev/vgdata/lvol1

Performance

Performance

top display Linux processes top -b -n 4 -d 5 ← interval 5sec , 4 times
sar Collect, report, or save system activity information. sar -f /var/log/sa/sa16
sar (cpu,io)
sar -r (memory)
sar -q (Loadaverage)
vmstat LIKE Report virtual memory statistics vmstat 1 ← interval 1sec (cpu, io, memory, swap)
vmstat 1 5 ← interval 1sec, 5 times (cpu, io, memory, swap)
iostat Report Central Processing Unit (CPU) statistics and input/output statistics for devices and partitions. iostat -xtk 1 (cpu, io) ← interval 1sec
mpstat Report processors related statistics. mpstat -P ALL
uptime Tell how long the system has been running. while : ; do uptime ; sleep 1 ; done
while : ; do uptime » /tmp/tmp.txt ; sleep 1 ; done
w Show who is logged on and what they are doing.
free Display amount of free and used memory in the system free -m ← show output in MB
tcpdump dump traffic on a network tcpdump -n port 80 -i any
tcpdump -n not arp and not port 123 and not port 22
tcpdump host 192.168.0.10 -n -w /tmp/20110615.pcap
tcpdump -r /tmp/20110615.pcap ← -r : Read packets from file
netstat Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships netstat -anp (-a : Show both listening and non-listening sockets.)
netstat -rn (-r : Display the kernel routing tables.)
iotop simple top-like I/O monitor iotop -b -n 4 -d 15 ← interval 15sec , 4 times
dstat LIKE versatile tool for generating system resource statistics dstat -taf

Load Test

fio

Software

Software

make GNU make utility to maintain groups of programs
patch apply a diff file to an original patch -p1 -N < ../xxx.patch
ldd print shared library dependencies ldd BINARY
yum popular an interactive, rpm based, package manager yum repolist ← check enabled repository
yum search STRINGS
yum info PACKAGE ← check rpm version etc
yum install PACKAGE
yum –disablerepo=* –enablerepo=test-repo repolist
rpm RPM Package Manager rpm -ivh PACKAGE.rpm ← install
rpm -e PACAGE.rpm ← uninstall
rpm -qa –last
apt
dpkg
alien alien -d package-x.x.x.rpm
alien -r package-x.x.x.deb
update-alternatives update-alternatives –config mta
rhn_register rhn_register –nox –proxy=http://192.168.0.10:9999

etc

X Window System

startx initialize an X session startx
xhost server access control program for X xhost + ← Access is granted to everyone
xauth X authority file utility

TUI

ntsysv simple interface for configuring runlevels
authconfig-tui an interface for configuring system authentication resources
system-config-securitylevel
system-config-network-tui

etc

md5sum compute and check MD5 message digest find . -type f -exec md5sum {} \; > /tmp/md5.out
← check all files
gpg OpenPGP encryption and signing tool
screen
kermit

Total Commander

Intro

Total Commander is a file manager for Windows, a program like Windows Explorer to copy, move or delete files. However, Total Commander can do much more than Explorer, e.g. pack and unpack files, access ftp servers, compare files by content, etc!
It was known as Windows Commander and in 2002 there was a name change – the new name is “Total Commander”.
See the latest version at https://www.ghisler.com/

Shortcuts

F1 Help
F2 Reread source window
F3 List files
F4 Edit files
F5 Copy files
F6 Rename or move files
F7 Create directory
F8 Delete files to recycle bin /delete directly – according to configuration (or Delete)
F9 Activate menu above source window (left or right)
F10 Activate left menu or deactivate menu
Alt+F1 change left drive
Alt+F2 change right drive
Alt+F3 Use alternate (external or internal) viewer
Alt+Shift+F3 Start Lister and load file with internal viewer (no plugins or multimedia)
Alt+F4 Exit | Minimize (with option MinimizeOnClose in wincmd.ini)
Alt+F5 Pack files
Alt+Shift+F5 Move to archive
Alt+F6 Unpack specified files from archive under cursor, or selected archives (use Alt+F9 on Windows 95)
Alt+F7 Find
Alt+F8 Opens the history list of the command line
Alt+F9 Same as ALT+F6 (because ALT+F6 is broken on Windows 95)
Alt+Shift+F9 Test archives
Alt+F10 Opens a dialog box with the current directory tree
Alt+F11 Opens left current directory bar (breadcrumb bar)
Alt+F12 Opens right current directory bar (breadcrumb bar)
Alt+Shift+F11 Focus the button bar to use it with the keyboard
Shift+F1 Custom columns view menu
Shift+F2 Compare file lists
Shift+F3 List only file under cursor, when multiple files selected
Shift+F4 Create new text file and load into editor
Shift+F5 Copy files (with rename) in the same directory
Shift+Ctrl+F5 Create shortcuts of the selected files
Shift+F6 Rename files in the same directory
Shift+F8/Delete Delete directly / delete to recycle bin – according to configuration
Shift+F10 Show context menu
Shift+Esc Minimizes Total Commander to an icon
Alt+Arrow left / Arrow right Go to previous/next dir of already visited dirs
Alt+Arrow down Open history list of already visited dirs (like the history list in a WWW browser)
Num + Expand selection (configurable: just files or files and folders)
Num – Shrink selection
Num * Invert selection (also with shift, see link)
Num / Restore selection
Shift+Num+[+] Like Num +, but files and folders if Num + selects just files (and vice versa)
Shift+Num+- Always removes the selection just from files (Num – from files and folders)
Shift+Num+* Like Num *, but files and folders if Num * inverts selection of just files (and vice versa)
Ctrl+Num + Select all (configurable: just files or files and folders)
Ctrl+Shift+Num + Select all (files and folders if CTRL+Num + selects only files)
Ctrl+Num – Deselect all (always files and folders)
Ctrl+Shift+Num – Deselect all (always files, no folders)
Alt+Num + Select all files with the same extension
Alt+Num – Remove selection from files with the same extension
Ctrl+Page up Change to parent directory (cd ..) , or Backspace
Ctrl+< Jump to the root directory (most European keyboards)
Ctrl+\ Jump to the root directory (US keyboard)
Ctrl+Page down Open directory/archive (also self extracting .EXE archives)
Ctrl+Arrow left / Arrow right Open directory/archive and display it in the target window. If the cursor is not on a directory name, or the other panel is active, then the current directory is displayed instead.
Ctrl+F1 File display ‘brief’ (only file names)
Ctrl+Shift+F1 Thumbnails view (preview pictures)
Ctrl+F2 File display ‘full’ (all file details)
Ctrl+Shift+F2 Comments view (new comments are created with Ctrl+Z)
Ctrl+F3 Sort by name
Ctrl+F4 Sort by extension
Ctrl+F5 Sort by date/time
Ctrl+F6 Sort by size
Ctrl+F7 Unsorted
Ctrl+F8 Display directory tree
Ctrl+Shift+F8 Cycle through separate directory tree states: one tree, two trees, off
Ctrl+F9 Print file under cursor using the associated program
Ctrl+F10 Show all files
Ctrl+F11 Show only programs
Ctrl+F12 Show user defined files
Tab Switch between left and right file list
Shift+Tab Switch between current file list and separate tree (if enabled)
Insert Select file or directory.
Space Select file or directory (as INSERT). If SPACE is used on an unselected directory under the cursor, the contents in this directory are counted and the size is shown in the “full” view instead of the string . This can be disabled through ‘Configuration’ – ‘Options’ – ‘Operation’ – ‘Selection with Space’.
Enter Change directory / run program / run associated program / execute command line if not empty. If the source directory shows the contents of an archive, further information on the packed file is given.
Shift+Enter 1. Runs command line / program under cursor with preceding command /c and leave the program’s window open. Only works if NOCLOSE.PIF is in your Windows directory! 2. With ZIP files: use alternative choice of these (as chosen in Packer config): (Treat archives like directories <-> call associated program, i.e. winzip or quinzip) 3. In the list of last used dirs (History, Ctrl+D), open the directory on a new Tab.
Alt+Shift+Enter The contents of all directories in the current directory are counted. The sizes of the directories are then shown in the “full” view instead of the string . Abort by holding down ESC key.
Alt+Enter Show property sheet.
Ctrl+a Select all
Ctrl+b Directory branch: Show contents of current dir and all subdirs in one list
Ctrl+Shift+b Selected directory branch: Show selected files, and all in selected subdirs
Ctrl+c Copy files to clipboard
Ctrl+x Cut files to clipboard
Ctrl+v Paste from clipboard to current dir.
Ctrl+d Open directory hotlist (‘bookmarks’)
Ctrl+f Connect to FTP server
Ctrl+Shift+f Disconnect from FTP server
Ctrl+i Switch to target directory
Ctrl+l Calculate occupied space (of the selected files)
Ctrl+m Multi-Rename-Tool
Ctrl+Shift+m Change FTP transfer mode
Ctrl+n New FTP connection (enter URL or host address)
Ctrl+p Copy current path to command line
Ctrl+q Quick view panel instead of file window
Ctrl+r Reread source directory
Ctrl+s Open Quick Filter dialog and activate filter (deactivate with ESC or CTRL+F10)
Ctrl+Shift+s Open Quick Filter dialog and reactivate last-used filter
Ctrl+t Open new folder tab and activate it
Ctrl+Shift+t Open new folder tab, but do not activate it
Ctrl+u Exchange directories
Ctrl+Shift+u Exchange directories and tabs
Ctrl+w Close currently active tab
Ctrl+Shift+w Close all open tabs
Ctrl+z Edit file comment
Ctrl+Arrow up Open dir under cursor in new tab
Ctrl+Shift+Arrow Up Open dir under cursor in other window (new tab)
Ctrl+Tab/Ctrl+Shift+Tab Jump to next tab / jump to previous tab
Ctrl+Alt+Letter Quick search for a file name (starting with specified letters) in the current directory (Support hotkeys Ctrl+X, Ctrl+C, Ctrl+V and Ctrl+A; use Ctrl+S for search filter on/off)

FTP

Ctrl+F Connect to FTP Server
Ctrl+SHIFT+F Disconnect current FTP connection
Ctrl+N New FTP connection

 

 

 

Selections

Insert­/Space Select current file/f­older
Num * Invert selection
Num / Restore selection
Ctrl+A Select all
Ctrl+l Calculate occupied space of selecte files
Ctrl+Num – Deselect all
Alt+Num+ Select all files with extension
Alt+Num- Deselect all files with extension

 

 

 

 

 

 

Selections

Alt+F1 Change left drive
Alt+F2 Change right drive
Alt+Arrow Down Open list of visited direct­ories
Alt+Arrow Left Jump to previous directory
Alt+Arrow Right Jump to next directory
Ctrl+< Jump to root directory
Backspace Change to parent directory
Tab Switch between left and right file list

 

 

 

 

 

 

Navigation

Alt+F1 Change left drive
Alt+F2 Change right drive
Alt+Arrow Down Open list of visited direct­ories
Alt+Arrow Left Jump to previous directory
Alt+Arrow Right Jump to next directory
Ctrl+< Jump to root directory
Backspace Change to parent directory
Tab Switch between left and right file list

 

 

 

 

 

 

View

Ctrl+u Swap left & right view
F2/Ctrl+r Refresh current directory
Ctrl+b Show contents of current dir and all subdirs in one list
Ctrl+S­hift+B Selected directory branch
Alt+Enter Show file properties window
F1 Help
Ctrl+l Calculate occupied space (of selecte files)

 

 

 

 

 

 

File manipu­lation

F3 List file contents
Shift+F3 List file under cursor with multiple files selected
F4 Edit files
Shift+F4 Create new text file and load in editor
F5/Ctrl+c Copy file
Shift+F5 Copy files (with rename) in same directory
F6 Rename or move files
Shift+F6 Rename files in same directory
F7 Create directory
F8/Delete Delete files
Ctrl+v Paste file in current directory
Ctrl+x Cut file
Ctrl+m Multi-­rename tool

 

 

 

 

 

 

 

 

 

 

Archiving

Alt+F5 Pack files
Alt+Sh­ift+F5 Move to archive
Alt+F6 Unpack from archive under cursor
Alt+Sh­ift+F9 Test archives

 

 

 

 

File sorting

Ctrl+F3 Sort by name
Ctrl+F4 Sort by extension
Ctrl+F5 Sort by date/time
Ctrl+F6 Sort by size
Ctrl+F7 Unsorted

 

 

 

 

Searching

Ctrl+s Quick search
Alt+F7 Find

 

 

 

Command Line with TC

%comspec%            Envoke CMD (ancient times)
CMD                         Envoke CMD
CMD /C                    Carries out the command specified by string and then terminates
CMD /K                    Carries out the command specified by string but remains
(For more complete CMD with switches see relevant CMD cheatsheet)

 

Other

Ctrl+Shift+w                              Close all open tabs
Ctrl+z                                          Edit file comment
Ctrl+Arrow up                           Open dir under cursor in new tab
Ctrl+Shift+Arrow                     Up Open dir under cursor in other window (new tab)
Ctrl+Tab/Ctrl+Shift+Tab        Jump to next tab / jump to previous tab
Ctrl+Alt+Letter                          Quick search for a file name (starting with specified letters) in the current directory
                                                       (Support hotkeys Ctrl+X, Ctrl+C, Ctrl+V and Ctrl+A; use Ctrl+S for search filter on/off)

Subnet Mask Cheat Sheet

Classes

Class Leading bits Size of network number bit field Size of rest bit field Number of networks Addresses per network Total addresses in class Start address End address Default subnet mask in dot-decimal notation CIDR notation
Class A 0 8 24 128 (27) 16,777,216 (224) 2,147,483,648 (231) 0.0.0.0 127.0.0.0[a] 255.0.0.0 /8
Class B 10 16 16 16,384 (214) 65,536 (216) 1,073,741,824 (230) 128.0.0.0 191.255.0.0 255.255.0.0 /16
Class C 110 24 8 2,097,152 (221) 256 (28) 536,870,912 (229) 192.0.0.0 223.255.255.0 255.255.255.0 /24
Class D (multicast) 1110 not defined not defined not defined not defined 268,435,456 (228) 224.0.0.0 239.255.255.255 not defined not defined
Class E (reserved) 1111 not defined not defined not defined not defined 268,435,456 (228) 240.0.0.0 255.255.255.255 not defined not defined

In more details

AddressesHostsNetmaskAmount of a Class C
/3042255.255.255.2521/64
/2986255.255.255.2481/32
/281614255.255.255.2401/16
/273230255.255.255.2241/8
/266462255.255.255.1921/4
/25128126255.255.255.1281/2
/24256254255.255.255.01
/23512510255.255.254.02
/2210241022255.255.252.04
/2120482046255.255.248.08
/2040964094255.255.240.016
/1981928190255.255.224.032
/181638416382255.255.192.064
/173276832766255.255.128.0128
/166553665534255.255.0.0256

Guide to sub-class C blocks

/25 — 2 Subnets — 126 Hosts/Subnet

Network #IP RangeBroadcast
.0.1-.126.127
.128.129-.254.255

/26 — 4 Subnets — 62 Hosts/Subnet

Network #IP RangeBroadcast
.0.1-.62.63
.64.65-.126.127
.128.129-.190.191
.192.193-.254.255

/27 — 8 Subnets — 30 Hosts/Subnet

Network #IP RangeBroadcast
.0.1-.30.31
.32.33-.62.63
.64.65-.94.95
.96.97-.126.127
.128.129-.158.159
.160.161-.190.191
.192.193-.222.223
.224.225-.254.255

/28 — 16 Subnets — 14 Hosts/Subnet

Network #IP RangeBroadcast
.0.1-.14.15
.16.17-.30.31
.32.33-.46.47
.48.49-.62.63
.64.65-.78.79
.80.81-.94.95
.96.97-.110.111
.112.113-.126.127
.128.129-.142.143
.144.145-.158.159
.160.161-.174.175
.176.177-.190.191
.192.193-.206.207
.208.209-.222.223
.224.225-.238.239
.240.241-.254.255

/29 — 32 Subnets — 6 Hosts/Subnet

Network #IP RangeBroadcast
.0.1-.6.7
.8.9-.14.15
.16.17-.22.23
.24.25-.30.31
.32.33-.38.39
.40.41-.46.47
.48.49-.54.55
.56.57-.62.63
.64.65-.70.71
.72.73-.78.79
.80.81-.86.87
.88.89-.94.95
.96.97-.102.103
.104.105-.110.111
.112.113-.118.119
.120.121-.126.127
.128.129-.134.135
.136.137-.142.143
.144.145-.150.151
.152.153-.158.159
.160.161-.166.167
.168.169-.174.175
.176.177-.182.183
.184.185-.190.191
.192.193-.198.199
.200.201-.206.207
.208.209-.214.215
.216.217-.222.223
.224.225-.230.231
.232.233-.238.239
.240.241-.246.247
.248.249-.254.255

/30 — 64 Subnets — 2 Hosts/Subnet

Network #IP RangeBroadcast
.0.1-.2.3
.4.5-.6.7
.8.9-.10.11
.12.13-.14.15
.16.17-.18.19
.20.21-.22.23
.24.25-.26.27
.28.29-.30.31
.32.33-.34.35
.36.37-.38.39
.40.41-.42.43
.44.45-.46.47
.48.49-.50.51
.52.53-.54.55
.56.57-.58.59
.60.61-.62.63
.64.65-.66.67
.68.69-.70.71
.72.73-.74.75
.76.77-.78.79
.80.81-.82.83
.84.85-.86.87
.88.89-.90.91
.92.93-.94.95
.96.97-.98.99
.100.101-.102.103
.104.105-.106.107
.108.109-.110.111
.112.113-.114.115
.116.117-.118.119
.120.121-.122.123
.124.125-.126.127
.128.129-.130.131
.132.133-.134.135
.136.137-.138.139
.140.141-.142.143
.144.145-.146.147
.148.149-.150.151
.152.153-.154.155
.156.157-.158.159
.160.161-.162.163
.164.165-.166.167
.168.169-.170.171
.172.173-.174.175
.176.177-.178.179
.180.181-.182.183
.184.185-.186.187
.188.189-.190.191
.192.193-.194.195
.196.197-.198.199
.200.201-.202.203
.204.205-.206.207
.208.209-.210.211
.212.213-.214.215
.216.217-.218.219
.220.221-.222.223
.224.225-.226.227
.228.229-.230.231
.232.233-.234.235
.236.237-.238.239
.240.241-.242.243
.244.245-.246.247
.248.249-.250.251
.252.253-.254.255

Classes represented with Bits

In the following table:

  • n indicates a bit used for the network ID.
  • H indicates a bit used for the host ID.
  • X indicates a bit without a specified purpose.
Class A
  0.  0.  0.  0 = 00000000.00000000.00000000.00000000
127.255.255.255 = 01111111.11111111.11111111.11111111
                  0nnnnnnn.HHHHHHHH.HHHHHHHH.HHHHHHHH

Class B
128.  0.  0.  0 = 10000000.00000000.00000000.00000000
191.255.255.255 = 10111111.11111111.11111111.11111111
                  10nnnnnn.nnnnnnnn.HHHHHHHH.HHHHHHHH

Class C
192.  0.  0.  0 = 11000000.00000000.00000000.00000000
223.255.255.255 = 11011111.11111111.11111111.11111111
                  110nnnnn.nnnnnnnn.nnnnnnnn.HHHHHHHH

Class D
224.  0.  0.  0 = 11100000.00000000.00000000.00000000
239.255.255.255 = 11101111.11111111.11111111.11111111
                  1110XXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX

Class E
240.  0.  0.  0 = 11110000.00000000.00000000.00000000
255.255.255.255 = 11111111.11111111.11111111.11111111
                  1111XXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX

Table

   The following table lists the variable length subnets from 1 to 32,
   the CIDR [3] representation form (/xx) and the Decmial equivalents.
   (M = Million, K=Thousand, A,B,C= traditional class values)

   Mask value:                             # of
   Hex            CIDR   Decimal           addresses  Classfull
   80.00.00.00    /1     128.0.0.0         2048 M     128 A
   C0.00.00.00    /2     192.0.0.0         1024 M      64 A
   E0.00.00.00    /3     224.0.0.0          512 M      32 A
   F0.00.00.00    /4     240.0.0.0          256 M      16 A
   F8.00.00.00    /5     248.0.0.0          128 M       8 A
   FC.00.00.00    /6     252.0.0.0           64 M       4 A
   FE.00.00.00    /7     254.0.0.0           32 M       2 A
   FF.00.00.00    /8     255.0.0.0           16 M       1 A
   FF.80.00.00    /9     255.128.0.0          8 M     128 B
   FF.C0.00.00   /10     255.192.0.0          4 M      64 B
   FF.E0.00.00   /11     255.224.0.0          2 M      32 B
   FF.F0.00.00   /12     255.240.0.0       1024 K      16 B
   FF.F8.00.00   /13     255.248.0.0        512 K       8 B
   FF.FC.00.00   /14     255.252.0.0        256 K       4 B
   FF.FE.00.00   /15     255.254.0.0        128 K       2 B
   FF.FF.00.00   /16     255.255.0.0         64 K       1 B
   FF.FF.80.00   /17     255.255.128.0       32 K     128 C
   FF.FF.C0.00   /18     255.255.192.0       16 K      64 C
   FF.FF.E0.00   /19     255.255.224.0        8 K      32 C
   FF.FF.F0.00   /20     255.255.240.0        4 K      16 C
   FF.FF.F8.00   /21     255.255.248.0        2 K       8 C
   FF.FF.FC.00   /22     255.255.252.0        1 K       4 C
   FF.FF.FE.00   /23     255.255.254.0      512         2 C
   FF.FF.FF.00   /24     255.255.255.0      256         1 C
   FF.FF.FF.80   /25     255.255.255.128    128       1/2 C
   FF.FF.FF.C0   /26     255.255.255.192     64       1/4 C
   FF.FF.FF.E0   /27     255.255.255.224     32       1/8 C
   FF.FF.FF.F0   /28     255.255.255.240     16      1/16 C
   FF.FF.FF.F8   /29     255.255.255.248      8      1/32 C
   FF.FF.FF.FC   /30     255.255.255.252      4      1/64 C
   FF.FF.FF.FE   /31     255.255.255.254      2     1/128 C
   FF.FF.FF.FF   /32     255.255.255.255   This is a single host route
 Table 1-1 represents traditional subnetting of a Class B network
   address.

Subnet Mask     # of nets    Net. Addr.  Host Addr Range  Brodcast Addr.
Bits of Subnet  hosts/subnet

255.255.128.0   2 nets        N.N.0.0     N.N.0-127.N      N.N.127.255
1 bit subnet    32766         N.N.128.0   N.N.128-254.N    N.N.254.255

255.255.192.0   4 nets        N.N.0.0     N.N.0-63.N       N.N.63.255
2 bit subnet    16382         N.N.64.0    N.N.64-127.N     N.N.127.255
                              N.N.128.0   N.N.128-191.N    N.N.191.255
                              N.N.192.0   N.N.192-254.N    N.N.254.255

255.255.224.0   8 nets        N.N.0.0     N.N.0-31.N       N.N.31.255
3 bit subnet    8190          N.N.32.0    N.N.32-63.N      N.N.63.255
                              N.N.64.0    N.N.64-95.N      N.N.95.255
                              N.N.96.0    N.N.96-127.N     N.N.127.255
                              N.N.128.0   N.N.128-159.N    N.N.159.255
                              N.N.160.0   N.N.160-191.N    N.N.191.255
                              N.N.192.0   N.N.192-223.N    N.N.223.255
                              N.N.224.0   N.N.224-254.N    N.N.254.255

255.255.240.0   16 nets       N.N.0.0     N.N.0-15.N       N.N.15.255
4 bit subnet    4094          N.N.16.0    N.N.16-31.N      N.N.31.255
                              N.N.32.0    N.N.32-47.N      N.N.47.255
                              N.N.48.0    N.N.48-63.N      N.N.63.255
                              N.N.64.0    N.N.64-79.N      N.N.79.255
                              N.N.80.0    N.N.80-95.N      N.N.95.255
                              N.N.96.0    N.N.96-111.N     N.N.111.255
                              N.N.112.0   N.N.112-127.N    N.N.127.255
                              N.N.128.0   N.N.128-143.N    N.N.143.255
                              N.N.144.0   N.N.144-159.N    N.N.159.255
                              N.N.160.0   N.N.160-175.N    N.N.175.255
                              N.N.176.0   N.N.176-191.N    N.N.191.255
                              N.N.192.0   N.N.192-207.N    N.N.207.255
                              N.N.208.0   N.N.208-223.N    N.N.223.255
                              N.N.224.0   N.N.224-239.N    N.N.239.255
                              N.N.240.0   N.N.240-254.N    N.N.254.255
FC 1878                      Subnet Table                 December 1995


255.255.248.0   32 nets       N.N.0.0     N.N.0-7.N        N.N.7.255
5 bit subnet    2046          N.N.8.0     N.N.8-15.N       N.N.15.255
                              N.N.16.0    N.N.16-23.N      N.N.23.255
                              N.N.24.0    N.N.24-31.N      N.N.31.255
                              N.N.32.0    N.N.32-39.N      N.N.39.255
                              N.N.40.0    N.N.40-47.N      N.N.47.255
                              N.N.48.0    N.N.48-55.N      N.N.55.255
                              N.N.56.0    N.N.56-63.N      N.N.63.255
                              N.N.64.0    N.N.64-71.N      N.N.71.255
                              N.N.72.0    N.N.72-79.N      N.N.79.255
                              N.N.80.0    N.N.80-87.N      N.N.87.255
                              N.N.88.0    N.N.88-95.N      N.N.95.255
                              N.N.96.0    N.N.96-103.N     N.N.103.255
                              N.N.104.0   N.N.104-111.N    N.N.111.255
                              N.N.112.0   N.N.112-119.N    N.N.119.255
                              N.N.120.0   N.N.120-127.N    N.N.127.255
                              N.N.128.0   N.N.128-135.N    N.N.135.255
                              N.N.136.0   N.N.136-143.N    N.N.143.255
                              N.N.144.0   N.N.144-151.N    N.N.151.255
                              N.N.152.0   N.N.152-159.N    N.N.159.255
                              N.N.160.0   N.N.160-167.N    N.N.167.255
                              N.N.168.0   N.N.168-175.N    N.N.175.255
                              N.N.176.0   N.N.176-183.N    N.N.183.255
                              N.N.184.0   N.N.184-191.N    N.N.191.255
                              N.N.192.0   N.N.192-199.N    N.N.199.255
                              N.N.200.0   N.N.200-207.N    N.N.207.255
                              N.N.208.0   N.N.208-215.N    N.N.215.255
                              N.N.216.0   N.N.216-223.N    N.N.223.255
                              N.N.224.0   N.N.224-231.N    N.N.231.255
                              N.N.232.0   N.N.232-239.N    N.N.239.255
                              N.N.240.0   N.N.240-247.N    N.N.247.255
                              N.N.248.0   N.N.248-254.N    N.N.254.255

255.255.252.0   64 nets       N.N.0.0     N.N.0-3.N        N.N.3.255
6 bit subnet    1022          N.N.4.0     N.N.4-7.N        N.N.7.255
                              N.N.8.0     N.N.8-11.N       N.N.11.255
                              N.N.12.0    N.N.12-15.N      N.N.15.255
                              N.N.240.0   N.N.240-243.N    N.N.243.255
                              N.N.244.0   N.N.244-247.N    N.N.247.255
                              N.N.248.0   N.N.248-251.N    N.N.251.255
                              N.N.252.0   N.N.252-254.N    N.N.254.255


255.255.254.0   128 nets      N.N.0.0     N.N.0-1.N        N.N.1.255
7 bit subnet    510           N.N.2.0     N.N.2-3.N        N.N.3.255
                              N.N.4.0     N.N.4-5.N        N.N.5.255
                              N.N.250.0   N.N.250-251.N    N.N.251.255
                              N.N.252.0   N.N.252-253.N    N.N.253.255



Pummill & Manning            Informational                      [Page 4]

RFC 1878                      Subnet Table                 December 1995


                              N.N.254.0   N.N.254.N        N.N.254.255


255.255.255.0   255 nets      N.N.0.0     N.N.0.N          N.N.0.255
8 bit subnet    253           N.N.1.0     N.N.1.N          N.N.1.255
                              N.N.252.0   N.N.252.N        N.N.252.255
                              N.N.253.0   N.N.253.N        N.N.253.255
                              N.N.254.0   N.N.254.N        N.N.254.255

   Table 1-2 represents traditional subnetting of a Class C network
   address (which is identical to extended Class B subnets).

Subnet Mask     # of nets    Net. Addr.  Host Addr Range  Brodcast Addr.
Bits of Subnet  hosts/subnet

255.255.255.128 2 nets       N.N.N.0     N.N.N.1-126      N.N.N.127
1 bit Class C   126          N.N.N.128   N.N.N.129-254    N.N.N.255
9 bit Class B



255.255.255.192 4 nets       N.N.N.0     N.N.N.1-62       N.N.N.63
2 bit Class C   62           N.N.N.64    N.N.N.65-126     N.N.N.127
10 bit Class B               N.N.N.128   N.N.N.129-190    N.N.N.191
                             N.N.N.192   N.N.N.193-254    N.N.N.255

255.255.255.224 8 nets       N.N.N.0     N.N.N.1-30       N.N.N.31
3 bit Class C   30           N.N.N.32    N.N.N.33-62      N.N.N.63
11 bit Class B               N.N.N.64    N.N.N.65-94      N.N.N.95
                             N.N.N.96    N.N.N.97-126     N.N.N.127
                             N.N.N.128   N.N.N.129-158    N.N.N.159
                             N.N.N.160   N.N.N.161-190    N.N.N.191
                             N.N.N.192   N.N.N.193-222    N.N.N.223
                             N.N.N.224   N.N.N.225-254    N.N.N.255

255.255.255.240 16 nets      N.N.N.0     N.N.N.1-14       N.N.N.15
4 bit Class C   14           N.N.N.16    N.N.N.17-30      N.N.N.31
12 bit Class B               N.N.N.32    N.N.N.33-46      N.N.N.47
                             N.N.N.48    N.N.N.49-62      N.N.N.63
                             N.N.N.64    N.N.N.65-78      N.N.N.79
                             N.N.N.80    N.N.N.81-94      N.N.N.95
                             N.N.N.96    N.N.N.97-110     N.N.N.111
                             N.N.N.112   N.N.N.113-126    N.N.N.127
                             N.N.N.128   N.N.N.129-142    N.N.N.143
                             N.N.N.144   N.N.N.145-158    N.N.N.159
                             N.N.N.160   N.N.N.161-174    N.N.N.175
                             N.N.N.176   N.N.N.177-190    N.N.N.191
                             N.N.N.192   N.N.N.193-206    N.N.N.207



Pummill & Manning            Informational                      [Page 5]

RFC 1878                      Subnet Table                 December 1995


                             N.N.N.208   N.N.N.209-222    N.N.N.223
                             N.N.N.224   N.N.N.225-238    N.N.N.239
                             N.N.N.240   N.N.N.241-254    N.N.N.255


255.255.255.248 32 nets      N.N.N.0     N.N.N.1-6        N.N.N.7
5 bit Class C   6            N.N.N.8     N.N.N.9-14       N.N.N.15
13 bit Class B               N.N.N.16    N.N.N.17-22      N.N.N.23
                             N.N.N.24    N.N.N.25-30      N.N.N.31
                             N.N.N.32    N.N.N.33-38      N.N.N.39
                             N.N.N.40    N.N.N.41-46      N.N.N.47
                             N.N.N.48    N.N.N.49-54      N.N.N.55
                             N.N.N.56    N.N.N.57-62      N.N.N.63
                             N.N.N.64    N.N.N.65-70      N.N.N.71
                             N.N.N.72    N.N.N.73-78      N.N.N.79
                             N.N.N.80    N.N.N.81-86      N.N.N.87
                             N.N.N.88    N.N.N.89-94      N.N.N.95
                             N.N.N.96    N.N.N.97-102     N.N.N.103
                             N.N.N.104   N.N.N.105-110    N.N.N.111
                             N.N.N.112   N.N.N.113-118    N.N.N.119
                             N.N.N.120   N.N.N.121-126    N.N.N.127
                             N.N.N.128   N.N.N.129-134    N.N.N.135
                             N.N.N.136   N.N.N.137-142    N.N.N.143
                             N.N.N.144   N.N.N.145-150    N.N.N.151
                             N.N.N.152   N.N.N.153-158    N.N.N.159
                             N.N.N.160   N.N.N.161-166    N.N.N.167
                             N.N.N.168   N.N.N.169-174    N.N.N.175
                             N.N.N.176   N.N.N.177-182    N.N.N.183
                             N.N.N.184   N.N.N.185-190    N.N.N.191
                             N.N.N.192   N.N.N.193-198    N.N.N.199
                             N.N.N.200   N.N.N.201-206    N.N.N.207
                             N.N.N.208   N.N.N.209-214    N.N.N.215
                             N.N.N.216   N.N.N.217-222    N.N.N.223
                             N.N.N.224   N.N.N.225-230    N.N.N.231
                             N.N.N.232   N.N.N.233-238    N.N.N.239
                             N.N.N.240   N.N.N.241-246    N.N.N.247
                             N.N.N.248   N.N.N.249-254    N.N.N.255

255.255.255.252 64 nets      N.N.N.0     N.N.N.1-2        N.N.N.3
6 bit Class C   2            N.N.N.4     N.N.N.5-6        N.N.N.7
14 bit Class B               N.N.N.8     N.N.N.9-10       N.N.N.11
                             N.N.N.244   N.N.N.245-246    N.N.N.247
                             N.N.N.248   N.N.N.249-250    N.N.N.251
                             N.N.N.252   N.N.N.253-254    N.N.N.255







Pummill & Manning            Informational                      [Page 6]

RFC 1878                      Subnet Table                 December 1995


   For the sake of completeness within this memo, tables 2-1 and 2-2
   illistrate some options for subnet/host partions within selected
   block sizes using calculations which exclude all-zeros and all-ones
   subnets [2].  Many vendors only support subnetting based upon this
   premise.  This practice is obsolete!  Modern software will be able to
   utilize all definable networks.

Table 2-1 from a /16 block
# bits          Mask            Effective Subnets       Effective Hosts
========        =====           =================       ===============
2               255.255.192.0   2                       16382
3               255.255.224.0   6                       8190
4               255.255.240.0   14                      4094
5               255.255.248.0   30                      2046
6               255.255.252.0   62                      1022
7               255.255.254.0   126                     510
8               255.255.255.0   254                     254
9               255.255.255.128 510                     126
10              255.255.255.192 1022                    62
11              255.255.255.224 2046                    30
12              255.255.255.240 4094                    14
13              255.255.255.248 8190                    6
14              255.255.255.252 16382                   2

Table 2-2 from a /24 block
# bits          Mask            Effective Subnets       Effective Hosts
========        =====           =================       ===============
2               255.255.255.192 2                       62
3               255.255.255.224 6                       30
4               255.255.255.240 14                      14
5               255.255.255.248 30                      6
6               255.255.255.252 62                      2

Quick Cheatsheet

OSI & TCP/IP Models

First what is the OSI model? The OSI model is a framework of protocols that allows two devices to communicate on a network or over the internet. Each layer of the OSI model makes each layer responsible for over looking and carrying out a specific task. I’ve made a cheat sheet that breaks everything down into it’s most basic form. I will be referring to this chart throughout the rest of this post.

osi-cheat-sheet-01

The OSI layer is broken up into 7 layers. The top most layer is layer 7 and the lowest layer is Layer 1. Each layer has been given a name that helps identify what is happening on each layer.

Let’s go over the OSI Layer in more detail

Layer 7 is the Application layer. This is the layer that us a humans interact with the most. This layer the application sets up rules on how an application will send and receive data. Much like Languages, if both people don’t speak the same one, a conversation will not likely amount to anything.

Layer 6 is is the Presentation layer. It helps the Application layer by formatting the data in such a way that both parties will be able to read it.

Layer 5 is the Session layer. It helps ensure that the data is synchronized.

Layer 4 is the Transport layer. It is responsible for creating and managing the packets that will go out on the network.

Layer 3 is the Network layer. It is responsible for Addressing and Routing. This layer is in charge of the IP address of the hosts as well as knowing how to route information to another host. Because IP supports routing the destination host can be local or out the internet.

Layer 2 is the data link layer. It is responsible for Data frames and the Management of those frames. Data frames deal with layer 2 addresses (MAC Address) which are non-routable addresses. Technically Layer 2 can actually be broken up into two sub-layers:

  • Logical Link Control
  • Media Access Control (NIC’s Mac Address)

Layer 1 is the Physical Layer. It is responsible for talking with a physical device like a NIC. In particular it’s changing the data into electronic pulses that can be sent out on the wire.

Device Type by Layer

To give you a better idea what layers the network devices work at I created the device type column.

Layer 7 – I put gateway here. This is not the same as a “Default Gateway”. This is a device that works kind of like a translator. It is able to understand application languages like HTTP, SMTP, etc. The term “Next Generation Firewalls” is some times applied to these devices.

Layer 3 – Routers and “Swouters” devices go here. A Swouter is a layer 3 switch. It has more than a couple ports on the back and is capable of routing.

Layer 2 – This is the typical layer where switches are put. Switches are able to look at traffic and filter data based on MAC addresses.

Layer 1 – Typically Hubs and Repeaters are put here. You don’t really see them anymore because they tend to be slow and pretty brain dead. Because of this they only work “well” in a very small network design.

TCP/IP Model

You will notice that the TCP/IP model only has 4 layers. The four layers correlate to one or more of the OSI Model. Later versions have 5 and have different names. From what I’ve read we need to know both.

TCP/IP Stands for Transmission Control Protocol/Internet Protocol. It is the basic communication protocol of the Internet. It can be used on the internet as well as private networks. TCP/IP is based off the 4 layer Darpa model.  Looking back at the “Cheat sheet” you will notice that I’ve filled in a column with what protocols are used at each layer.

Transmission Protocols

There are two types of transmission protocol types in TCP/IP. These protocols are called TCP and UDP. TCP is like Certified Mail and UDP is like 1st class Mail. Only Certified mail tells you if the other side has received all packages.

TCP (Transmission Control Protocol)

  • One to One
  • Connection Oriented
  • Reliable Communication

UDP (User Datagram Protocol)

  • Multicast (one to many)
  • Connectionless
  • Unreliable

Connection orientated communication means that connection must be established before data can be exchanged. TCP uses a three-way handshake to establish this connection.

  1. Hi I’d like to talk
  2. Hi I got the info. Here’s how to talk to me
  3. Okay, Let’s begin talking

Internet Layer Protocols

IP

  • Protocol of the internet
  • Addressing
  • Routing

Arp

  • Type of Address Resolution Protocol
  • Resolves IP addresses to Hardware Address (MAC)

ICMP – Internet Control Message Protocol

  • Diagnostic and error reporting.
  • Ping uses ICMP

IGMP – Internet Group Management Protocol

  • Manages IP multicast group membership. Is NOT the same as ICMP!