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Find files with the same names in several directories.
cat file1 file2 file3|sort|uniq -d finds the same lines in several files, especially in files with lists of files.

get you public ip address
Relies on ifconfig.me functioning. It's about as easy as it gets, and memorable to old geeks too.

Delete DOS Characters via VIM (^M)
And in case you want to migrate back to, err.. MS-DOS: ":set ff=dos" does the opposite.

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" }

Recursively compare two directories and output their differences on a readable format

Ping Twitter to check if you can connect
Returns a JSON object, by connecting to the 'test' endpoint of the Twitter API. Simplest way to check if you can connect to Twitter. Output also available in XML, use '/help/test.xml' for that

send echo to socket network
Using netcat, usuallly installed on debian/ubuntu. Also to test against a sample server the following two commands may help echo got milk? | netcat -l -p 25 python -c "import SocketServer; SocketServer.BaseRequestHandler.handle = lambda self: self.request.send('got milk?\n'); SocketServer.TCPServer(('0.0.0.0', 25), SocketServer.BaseRequestHandler).serve_forever()"

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" }

Project your desktop using xrandr
HDMI-1 is the interface in the example, which can be obtained just by typing xrandr and surfing through the output. There are a hell lot of configurations that can be done but I prefer auto because it works in most cases. $ Lifesaver

Boooted as EFI/UEFI or BIOS


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