History usually only gives the command number and the command. This will add a timestamp to the history file. Note: this will only put the correct timestamp on commands used after the export is done. You may want to put this in your .bashrc Show Sample Output

Kudzu is available on CentOS, used for configuring and detecting new hardware device installed, is also usefull for device listing.

I use it sometimes when I work on a french file transferred from a windows XP to a Debian-UTF8 system. Those are not correctly displayed: ? ? ? and so on man tcs # for all charsets

Shows a file without comments (at least those starting by #) - removes empty lines - removes lines starting by # or "some spaces/tabs then #'" Useful when you want to quickly see what you have to customize on a freshly installed application without reading the comments that sometimes are a full 1000 lines documentation :) While posting, I saw this http://www.commandlinefu.com/commands/view/1041/display-contents-of-a-file-wo-any-comments-or-blank-lines But it's dirty and incomplete, to my mind My original goal was to remove lines like "\t*#" but I can't figure out how to do a egrep '\t' on a command-line. Two workarounds if needed: egrep -v 'press control + V then TAB then #' /your/file or egrep -v -f some_file /your/file #where some_file contains what you want to exclude, example a really inserted TAB

This is a simple but useful command to search for multiple terms in a file at once. This prevents you from having to do mutliple grep's of the same file. Show Sample Output

wraps text lines at the specified width (90 here). -s option is to force to wrap on blank characters -b count bytes instead of columns

Quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean, the regex can easily be upgraded to handle "in betweens" for mm dd or to validate other types of strings, ex. ip address. Boolean output could easily be piped into a condition for a more complete one-liner.

replace "directory name with files to add to DVD" with actual directory containing files you want to add to growable DVD

replace "directory name to burn on DVD" with actual directory name that you want to copy on DVD

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unalias a previously aliased command Show Sample Output

function echox { echo `tput cup $(($(tput lines))) $(( ($(tput cols) - $(echo "${#1}"))/2 ))`"$1"`tput cup $(tput lines) $(( $(tput cols)-1 ))`; } echox prints given argument on bottom line center screen in terminal function echoxy { echo `tput cup $(($(tput lines)/2)) $(( ($(tput cols) - $(echo "${#1}"))/2))`"$1"`tput cup $(tput lines) $(( $(tput cols)-1 ))`; } exhoxy prints given argument center screen function echos { echo `tput cup $(($(tput lines)-2)) $(($(tput cols)-$(echo ${#1})))&&tput sc`"$1"`tput cup $(($(tput lines)-2)) 0 && tput rc`; } while [ 1 ]; do echos "`date`"; done 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 Show Sample Output

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: echo '{ 1.2:3.4}' | python -m simplejson.tool Expecting property name: line 1 column 2 (char 2) Show Sample Output

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. Show Sample Output

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. Show Sample Output

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: gpg < folder.tpg | tar -xf -