unalias a previously aliased command

echox prints given argument on bottom line center screen in terminal

exhoxy prints given argument center screen

echos prints date and time on second from last line (used as status message)

you can easily use these functions by placing them in your .bashrc file, make sure to source your .bashrc once you do

You can use a site like http://www.jsonlint.com/ or use the command line to validate your long and complex json data. This is part of the simplejson package for python http://undefined.org/python/#simplejson.

Wrong json expression example:

Expecting property name: line 1 column 2 (char 2)

This works on my ubuntu/debian machines.

I suspect other distros need some tweaking of sort and cut.

I am sure someone could provide a shorter/faster version.

Consider this line :

random perl language this make possible is

is possible to rearrange words with $F perl variable and word index, starting from 0.

wmwave is part of wmwave package, when launched display a small wireless link monitor on your desktop with noise, level and link power.

setfont load vga console font. The default font directory is usually in /lib/kbd/consolefonts. Setfont is part of kbd package. Tested on CentOS.

ethstatus part of ethstatus package, is a consolle based monitor for network interfaces. Nicely display on screen a real time summary about bandwidth, speed and packets.

The variable ? contain the last exit status of a command, it can be printed for troubleshooting purpose.

I use this simple command for remove all backup files generated usually by editors like Vim and Emacs.

Removes an iptables rule created by fail2ban. This example shows how to remove a rule for an IP from the fail2ban-SSH chain. Can be used for any service monitored by fail2ban.

For more on fail2ban, see http://www.fail2ban.org/wiki/index.php/Main_Page

gpg's compression is as suitable as gzip's however your backups can now be encrypted.

to extract use:

remove file that has sensitive info safely. Overwrites it 33 times with zeros

deborphan(1) must be installed.

To decrypt the files replace "ccenrypt" with "ccdecrypt.

ccrypt(1) must be installed. It uses the AES (Rijndael) block cipher.

To make it handier create an alias.

Often I need to edit a bash or perl script I've written. I know it's in my path but I don't feel like typing the whole path (or I don't remember the path).

During this operation :

# mv Joomla_1.5.10-Stable-Full_Package.zip /var/www/joomla/

I invoke /var/www/joomla/ as last command argument. To change in this directory I can use

# cd !$

So I go to

hob:/var/www/joomla#

Assuming that 219,229 and 221 are entries in history, I recall them in a single line for execute multiple commands

219 ifdown wlan0

...

221 ifup wlan0

...

229 iwconfig wlan0 mode Managed

so the result is execution of # ifdown wlan0 ; iwconfig wlan0 mode Managed ; ifup wlan0

tailf same as tail -f follow the flow of a log file, showing it in real time to stdout.