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Determine what version of bind is running on a dns server.
Due to the recent dynamic update vulnerability with bind, I was forced to dig a little deeper into dig...

View non-printing characters with cat
Useful to detect number of tabs in an empty line, DOS newline (carriage return + newline). A tool that can help you understand why your parsing is not working.

Export a subset of a database
Limits the number of rows per table to X

defragment files
Thanks to flatcap for optimizing this command. This command takes advantage of the ext4 filesystem's resistance to fragmentation. By using this command, files that were previously fragmented will be copied / deleted / pasted essentially giving the filesystem another chance at saving the file contiguously. ( unlike FAT / NTFS, the *nix filesystem always try to save a file without fragmenting it ) My command only effects the home directory and only those files with your R/W (read / write ) permissions. There are two issues with this command: 1. it really won't help, it works, but linux doesn't suffer much (if any ) fragmentation and even fragmented files have fast I/O 2. it doesn't discriminate between fragmented and non-fragmented files, so a large ~/ directory with no fragments will take almost as long as an equally sized fragmented ~/ directory The benefits i managed to work into the command: 1. it only defragments files under 16mb, because a large file with fragments isn't as noticeable as a small file that's fragmented, and copy/ delete/ paste of large files would take too long 2. it gives a nice countdown in the terminal so you know how far how much progress is being made and just like other defragmenters you can stop at any time ( use ctrl+c ) 3. fast! i can defrag my ~/ directory in 11 seconds thanks to the ramdrive powering the command's temporary storage bottom line: 1. its only an experiment, safe ( i've used it several times for testing ), but probably not very effective ( unless you somehow have a fragmentation problem on linux ). might be a placebo for recent windows converts looking for a defrag utility on linux and won't accept no for an answer 2. it's my first commandlinefu command

urldecoding with one pure BASH builtin
You can use ordinary printf to convert "%23%21%2fbin%2fbash" into "#!/bin/bash" with no external utilities, by using a little known printf feature -- the "%b" specifier converts shell escapes. Replace % with \x and printf will understand the urlencoded string. BASH's printf has an extension to set a variable directly, too. So you get to convert urlencoded strings from garble to plaintext in one step with no externals and no backticks.

send a message to a windows machine in a popup
It will only work if the service NETSEND in the Windows machine is enabled.

vim's pastetoggle: when you press f9 'paste' is on , press f9 again and 'paste' is off, and so forth (works in insert-mode and command-mode)

Random play a mp3 file
Pick a mp3 at random and play it. Assumes the availability of locate with an updated db and mpg123 Not the most useful command I guess, but all of the really useful ones are taken...

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

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