MAC is acronym for for Media Access Control address. It is a unique identifier attached to almost most all networking equipment such as Routers, Ethernet cards and other devices.
If you do not have access to router admin interface (via telnet or webbased), use following method to find out router MAC address.
You need to use arp command (available on both Windows, Linux/Unixish systems).
arp manipulates the kernel’s ARP cache in various ways. The primary options are clearing an address mapping entry and manually setting up one. For debugging purposes, the arp program also allows a complete dump of the ARP cache.
arp shows the entries of the specified hosts. If the hostname parameter is not used, all entries will be displayed.
Task: Find out router Mac Address
To find out your router MAC address, use arp command as follows:
$ /usr/sbin/arp -a OR $ arp -a Output:
router (192.168.1.254) at 00:08:5C:00:00:01 [ether] on eth0
fbsd6 (192.168.1.16) at 00:0F:EA:91:04:07 [ether] on eth0
In above example 00:08:5C:00:00:01 is MAC address of my router. If you cannot find MAC address then just ping to your router once (my router had 192.168.1.254 IP) $ ping 192.168.1.254 And then run (type arp -a) above arp command again. If you have telnet access to router then you can just telnet into router and find out MAC address: $ telnet 192.168.1.254
Output:
Welcome to nixCraft Router!
Login: admin
Password:
Please note that your interface name (br0) could be different. You can also use ifconfig -a command.
Windows XP/NT/2003 find out Router Mac address
If you are using Microsoft Windows XP then you need to open MS-DOS shell prompt first. Click on Start > Run > Type cmd command followed by ENTER key. Then at C:\> prompt, type arp command as follows:
Si vous cherchez un utilitaire et une bibliothèque pour vos projets qui permette d’afficher dans un terminal une image en utilisant du code ANSI, j’ai ce qu’il vous faut. Ça s’appelle Picture-tube et pour l’installer c’est très simple. Il vous faudra npm, donc sous ubuntu pour installer un petit npm, il faut taper :
sudo apt-get install npm
Ensuite pour installer la bibliothèque Picture-tube, il faut faire :
sudo npm install picture-tube
Si seul l’outil en ligne de commande vous intéresse, ajoutez le paramètre -g
sudo npm install -g picture-tube
Ensuite, pour convertir une image, un petit
picture-tube monimage.jpg
dans le terminal et taaadaaa
Après, pour utiliser la bibliothèque, voici un exemple de code :
var pictureTube = require('picture-tube')
var tube = pictureTube();
tube.pipe(process.stdout);
var fs = require('fs');
fs.createReadStream('robot.png').pipe(tube);
mdfind command is the spotlight search from command line
say "Hello there"
The say command invokes the system text-to-speech capabilities.
cd -
Will restore the previous directory you were in. Very handy if you accidentally type cd and flip to home.
And some usefull aliases
alias ..="cd .." alias ...="cd .. ; cd .."
alias ls="ls -G" # list alias la="ls -Ga" # list all, includes dot files alias ll="ls -Gl" # long list, excludes dot files alias lla="ls -Gla" # long list all, includes dot files
alias stfu="osascript -e 'set volume output muted true'" alias pumpit="osascript -e 'set volume 10'"
alias ips="ifconfig -a | perl -nle'/(d .d .d .d )/ && print $1'" alias myip="dig short myip.opendns.com @resolver1.opendns.com"
Bash Keyboard Shortcuts
Moving the cursor:
Ctrl a Go to the beginning of the line (Home)
Ctrl e Go to the End of the line (End)
Hold the Option key and click on the current line = Jump Backwards
Ctrl p Previous command (Up arrow)
Ctrl n Next command (Down arrow)
Hold the Option key and click on a previous line = Jump upwards
Ctrl f Forward one character
Ctrl b Backward one character
Alt b Back (left) one word or use Option Right-Arrow
Alt f Forward (right) one word or use Option Left-Arrow
Ctrl xx Toggle between the start of line and current cursor position
Editing:
Ctrl L Clear the Screen, similar to the clear command
Alt Del Delete the Word before the cursor.
Alt d Delete the Word after the cursor.
Ctrl d Delete character under the cursor
Ctrl h Delete character before the cursor (backspace)
Ctrl w Cut the Word before the cursor to the clipboard.
Ctrl k Cut the Line after the cursor to the clipboard.
Ctrl u Cut/delete the Line before the cursor position.
Alt t Swap current word with previous
Ctrl t Swap the last two characters before the cursor (typo).
Esc t Swap the last two words before the cursor.
ctrl y Paste the last thing to be cut (yank)
Alt u UPPER capitalize every character from the cursor to the end of the current word.
Alt l Lower the case of every character from the cursor to the end of the current word.
Alt c Capitalize the character under the cursor and move to the end of the word.
Alt r Cancel the changes and put back the line as it was in the history (revert).
ctrl _ Undo
TAB Tab completion for file/directory names
For example, to move to a directory ‘sample1’; Type cd sam ; then press TAB and ENTER. type just enough characters to uniquely identify the directory you wish to open.
Special keys: Tab, Backspace, Enter, Esc
Text Terminals send characters (bytes), not key strokes. Special keys such as Tab, Backspace, Enter and Esc are encoded as control characters. Control characters are not printable, they display in the terminal as ^ and are intended to have an effect on applications.
Ctrl I = Tab
Ctrl J = Newline
Ctrl M = Enter
Ctrl [ = Escape
Many terminals will also send control characters for keys in the digit row:
Ctrl v tells the terminal to not interpret the following character, so Ctrl v Ctrl-I will display a tab character, similarly Ctrl v ENTER will display the escape sequence for the Enter key: ^M
History:
Ctrl r Recall the last command including the specified character(s)
searches the command history as you type.
Equivalent to : vim ~/.bash_history.
Ctrl p Previous command in history (i.e. walk back through the command history)
Ctrl n Next command in history (i.e. walk forward through the command history)
Alt . Use the last word of the previous command
Ctrl s Go back to the next most recent command.
(beware to not execute it from a terminal because this will also launch its XOFF).
Ctrl o Execute the command found via Ctrl r or Ctrl s
Ctrl g Escape from history searching mode
Process control:
Ctrl C Interrupt/Kill whatever you are running (SIGINT)
Ctrl l Clear the screen
Ctrl s Stop output to the screen (for long running verbose commands)
Ctrl q Allow output to the screen (if previously stopped using command above)
Ctrl D Send an EOF marker, unless disabled by an option, this will close the current shell (EXIT)
Ctrl Z Send the signal SIGTSTP to the current task, which suspends it.
To return to it later enter fg 'process name' (foreground).
To use the Alt Key Shortcuts in OS X – Open Terminal Preferences | Settings Tab | Keyboard | Tick « Use option as meta key »
Emacs mode vs Vi Mode
All the above assume that bash is running in the default Emacs setting, if you prefer this can be switched to Vi shortcuts instead.
In this post I cover the basics of rsync, in preparation for a subsequent post that will cover backups and it’s use in conjunction with cronjobs to automatize the backup process. From the copying and synchronization of local files and folders, to it’s use for transfer information among computers. Itsuse as a daemon when SSH is unavailable was moved to it’s own section.
rsync is a very versatile copying and backup tool that is included by default in almost every Linux distribution. It can be used as an advanced copying tool, allowing us to copy files both locally and remotely. It can also be used as a backup tool. It supports the creation of incremental backups.
rsync counts with a famous delta-transfer algorithm that allows us to transfer new files as well as recent changes to existent files, while ignoring unchanged files. Additionally to this, the behavior ofrsync can be throughly customized, helping us to automatize backups, it can also be run as a daemon to turn the computer into a host and allow rsync clients connect to it.
Besides the copying of local files and folders, rsync allow us to copy over SSH (Secure Shell), RSH (Remote Shell) and it can be run as a daemon in a computer and allow other computers to connect to it, when rsync is run as a daemon it listens to the port TCP 873.
When we use rsync as a daemon or when we use RSH, the data that is send between computers travels unencrypted, so, if you are transferring files between two computers in the same local network, this is useful, but this shouldn’t be used to transfer files over insecure networks, such as the Internet. For this purpose SSH is the way to go.
This is the main reason why I favor the use of SSH for my transfers, besides, since SSH is secure, many servers have the SSH daemon available. But the use of rsync as a daemon for transfers over fast connections, as is usually the case in a local network, is useful. I don’t have the RSH daemon running in my computers so you may find me a bit biased about SSH in the examples. The examples covering the transfer of files between two computers use SSH as the medium of transport, but in a separate post I cover the use of rsync as a daemon.