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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"

Set access and modification timestamps of a file using another one as reference
atime and mtime timestamps of $FILE2 is changed according to the ones of $FILE1. If $FILE2 doesn't exist is created.

Display command lines visible on commandlinefu.com homepage
Uses the fabulous Hpricot library to parse HTML from Ruby. Extracts all elements of "command' class and displays unescaped text from inside these elements. The following command can help install dependencies (apart from Ruby itself) $ gem sources -a http://gems.github.com && sudo gem install why-hpricot

Send keypresses to an X application
This is a (last resort) way to automate applications that provide no other ways for automation, it would send 'Hello world' to the currently active window. See the manpage (and the -text and -window entries) for how to send special characters and target specific windows. An example: Using xwininfo, I get the id of my XPlanet background window: alanceil@kvirasim:19:51:0:~> xwininfo xwininfo: Please select the window about which you would like information by clicking the mouse in that window. xwininfo: Window id: 0x3600001 "Xplanet 1.2.0" Absolute upper-left X: 0 (..etc..) Now I use xvkbd to tell it to close itself: xvkbd -xsendevent -window 0x3600001 -text "Q" Obviously, the best way is to put these commands in a shellscript - just make sure to include a short sleep (sleep .1 should suffice) after each xvkbd call, or some programs will become confused.

bulk dl files based on a pattern
-O switch creates local filename same as remote curl [][] -o #1#2 makes local files unique inserting sequence values into #x placeholders sequences can be alpha or numeric e.g [a-z] [1-25]

get a random 0/1, use it for on/off, yes/no
use it to add a random boolean switch to your script

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Print just line 4 from a textfile
Prints the 4th line and then quits. (Credit goes to flatcap in comments: http://www.commandlinefu.com/commands/view/6031/print-just-line-4-from-a-textfile#comment.)

Prints any IP out of a file

Convert a bunch of HTML files from ISO-8859-1 to UTF-8 file encoding in a folder and all sub-folders
This is my first attempt at converting all HTML files to UTF-8 file encoding, including all subfolders. Theres probably a much more compact way to do it, but I'm quite proud of it with my windows background ;)


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