Check These Out
this will cause any commands that you have executed in the current shell session to not be written in your bash_history file upon logout
Cycles continuously through a string printing each character with a random delay less than 1 second. First parameter is min, 2nd is max. Example: 1 3 means sleep random .1 to .3. Experiment with different values. The 3rd parameter is the string. The sleep will help with battery life/power consumption.
$ cycle 1 3 $(openssl rand 100 | xxd -p)
Fans of "The Shining" might get a kick out of this:
$ cycle 1 4 ' All work and no play makes Jack a dull boy.'
This example will close the pipe after transferring 100MB at a speed of 3MB per second.
create a copy of a video file without the audio tracs
Shows a list of packages which are no longer needed as dependencies of any package installed on your system.
works only in zsh
sends commands specified in $commandfile to the telnet-server specified by $telnetserver.
to have newlines in $commandfile interpreted as ENTER, save the file in CR+LF (aka "Windows-Textfile") format.
if you want to save the output in a separate file, use:
$nc $telnetserver 23 < $commandfile > $resultfile
This command allows you to see a preview of a picture via the terminal. It can be usefull when you are ssh'ing your server without X-forwarding.
To have en example of the output you can get with this command see http://www.vimeo.com/3721117
Download at http://inouire.net/image-couleur.html
Sources here: http://inouire.net/archives/image-couleur_source.tar.gz
This causes cp to detect and omit large blocks of nulls. Sparse files are useful for implying a lot of disk space without actually having to write it all out.
http://en.wikipedia.org/wiki/Sparse_file
You can use it in a pipe too:
$ dd if=/dev/zero bs=1M count=5 |cp --sparse=always /dev/stdin SPARSE_FILE
In certain cases you mighy need to monitor the server load caused by certain process. For example HTTP, while stress testing apache using ab (apache benchmark) you may want to monitor the server status,load, # of spawned HTTP processes, # of established connections, # of connections in close wait state, apache memory footprint etc.