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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"

Super Speedy Hexadecimal or Octal Calculations and Conversions to Decimal.
^Hexadecimal Ten minus Octal Ten is Eight(in Decimal). $ echo "$(( 0xaf )) = $(( 0257 ))" ^Hexadecimal AF and Octal 257 are both Decimal 175.

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"

List all Samba user name

Find unused IPs on a given subnet

Convert all .flac from a folder subtree in 192Kb mp3
find . -type f -iname '*.flac' # searches from the current folder recursively for .flac audio files | # the output (a .flac audio files with relative path from ./ ) is piped to while read FILE; do FILENAME="${FILE%.*}"; flac -cd "$FILE" | lame -b 192 - "${FILENAME}.mp3"; done # for each line on the list: # FILE gets the file with .flac extension and relative path # FILENAME gets FILE without the .flac extension # run flac for that FILE with output piped to lame conversion to mp3 using 192Kb bitrate

Outputs a 10-digit random number

"at" command w/o the resource usage/competition issues
EXAMPLES jb "next sun 12pm" "/bin/sh ~you/1.sh" & jb "2010-08-29 12:00:00" "~you/1.sh" & jb "29aug2010 gmt" ". ~you/1.sh" & jb 12:00p.m. "nohup ./1.sh" & jb 1min "echo stop!" & SEE ALSO parsedate(3) strftime(3)

Search for files in rpm repositorys. (Mandriva linux)
Look for an rpm that supplies a specific file that you don't yet have installed. extremely useful when you need something and don't know where it is.. or what its called. note: uses grep like syntax.

Alert on high ping to know if it's really laggy while playing
Online games have pretty good lag compensation nowadays, Sometimes though, you really want to get some warning about your latency, e.g. while playing Diablo III in Hardcore mode, so you know when to carefully quit the game b/c your flatmate started downloading all his torrents at once. This is done on Darwin. On Linux/*nix you would need to find another suitable command instead of `say` to spell out your latency. And I used fping because it's a little bit easier to get the latency value needed. Something similar with our regular ping command could look like this: $ while :; do a=$(ping -c1 google.com | grep -o 'time.*' | cut -d\= -f2 | cut -d\ -f1 | cut -b1-4); [[ $a > 40 ]] && say "ping is $a"; sleep 3; done


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