Commands by j3ffyang (1)

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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" }

Reboot as a different OS in Grub
This will reboot as the Grub 2 option.

Fill the screen with randomly colored lines
This one-liner fills the screen with randomly colored lines.

Poor man's ntpdate
If you don't have netcat, you can use curl.

Multiple SSH Tunnels
Thankfully, the ssh command allows you to specify multiple tunnels through the same server in one command. Remeber if you want a priviliged port on your machine, you must use root or sudo account.

List all available commands (bash, ksh93)

Find the package that installed a command

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"

Change wallpaper

Find out when your billion-second anniversary is (was).
This is the same command as this one, but for OS X. http://www.commandlinefu.com/commands/view/3053/find-out-when-your-billion-second-anniversary-is-was.

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