This will output the sound from your microphone port to the ssh target computer's speaker port. The sound quality is very bad, so you will hear a lot of hissing.

Waiting for your server to finish rebooting? Issue the command above and you will hear a beep when it comes online. The -i 60 flag tells ping to wait for 60 seconds between ping, putting less strain on your system. Vary it to your need. The -a flag tells ping to include an audible bell in the output when a package is received (that is, when your server comes online).

It deletes all removed files, updates what was modified, and adds new files.

Read 32GB zero's and throw them away. How fast is your system? Show Sample Output

Dumps a MySQL database over a compressed SSH tunnel and uses it as input to mysql - i think that is the fastest and best way to migrate a DB to a new server!

This command creates and burns a gapless audio CD with 99 tracks. Each track is a 30 second sine wave, the first is 1 Hz, the second 2 Hz, and so on, up to 99 Hz. This is useful for testing audio systems (how low can your bass go?) and for creating the constant vibrations needed to make non-Newtonian fluids (like cornstarch and water) crawl around. Note, this temporarily creates 500MB of .cdda files in the current directory. If you don't use the "rm" at the end of the command, you can burn more disks using cdrdao write cdrdao.toc Prerequisites: a blank CD-R in /dev/cdrw, sox (http://sox.sourceforge.net/), and cdrdao (http://cdrdao.sourceforge.net/). I'm also assuming a recent version of bash for the brace expansion (which just looks nicer than using seq(1), but isn't necessary). Show Sample Output

I save this to bin/iptrace and run "iptrace ipaddress" to get the Country, City and State of an ip address using the http://ipadress.com service. I add the following to my script to get a tinyurl of the map as well: URL=`lynx -dump http://www.ip-adress.com/ip_tracer/?QRY=$1|grep details|awk '{print $2}'` lynx -dump http://tinyurl.com/create.php?url=$URL|grep tinyurl|grep "19. http"|awk '{print $2}'

If you have some drive imaging to do, you can boot into any liveCD and use a commodity machine. The drives will be written in parallel. To improve efficiency, specify a larger block size in dd: dd if=/dev/sda bs=64k | tee >(dd of=/dev/sdb bs=64k) | dd of=/dev/sdc bs=64k To image more drives , insert them as additional arguments to tee: dd if=/dev/sda | tee >(dd of=/dev/sdb) >(dd of=/dev/sdc) >(dd of=/dev/sdd) | dd of=/dev/sde

In my example, the mount point is /media/mpdr1 and the FS is /dev/sdd1 /mountpoint-path = /media/mpdr1 filesystem=/dev/sdd1 Why this command ? Well, in fact, with some external devices I used to face some issues : during data transfer from the device to the internal drive, some errors occurred and the device was unmounted and remounted again in a different folder. In such situations, the command mountpoint gave a positive result even if the FS wasn't properly mounted, that's why I added the df part. And if the device is not properly mounted, the command tries to unmount, to create the folder (if it exists already it will also work) and finally mount the FS on the given mount point. Show Sample Output

This command utilizes 'pv' to show dd's progress. Notes on use with dd: -- dd block size (bs=...) is a widely debated command-line switch and should usually be between 1024 and 4096. You won't see much performance improvements beyond 4096, but regardless of the block size, dd will transfer every bit of data. -- pv's switch, '-s' should be as close to the size of the data source as possible. -- dd's out file, 'of=...' can be anything as the data within that file are the same regardless of the filename / extension. Show Sample Output

Create a temporary file that acts as swap space. In this example it's a 1GB file at the root of the file system. This additional capacity is added to the existing swap space. Show Sample Output

To install a theme use: sudo firefox -install-global-theme /path/to/theme You can get the .xpi or .jar file from the versions history on the add-on/theme page. NOTE: may not work in your system (Debian-based is an example).

read the memory from C:0000 to F:FFFF without the need auf dmidecode

"killall -USR1 dd" does not work in OS X for me. However, sending INFO instead of USR1 works. Show Sample Output

This will create an exact duplicate image of your hard drive that you can then restore by simply reversing the "if" & "of" locations. sudo dd if=/media/disk/backup/sda.backup of=/dev/sda Alternatively, you can use an SSH connection to do your backups: dd if=/dev/sda | ssh user@ssh.server.com dd of=~/backup/sda.backup

This line removes the 300k header from a Nero image file converting it to ISO format

checks which files are not under version control, fetches the names and runs them through "svn add". WARNING: doesn't work with white spaces.

the command is obvious, I know, but maybe not everyone knows that using the parameter "-l" you can limit the use of bandwidth command scp. In this example fetch all files from the directory zutaniddu and I copy them locally using only 10 Kbs

This version was mentioned in the comments. Credits go to flatcap.