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Fetch the Gateway Ip Address
This is to fetch the Gateway Ip Address of a machine. Use the below format to put the value in a variable if you wish to find the gateway ip in a script $GATEWAY=$(netstat -nr | awk 'BEGIN {while ($3!="0.0.0.0") getline; print $2}')

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" }

Remove trailing space in vi

Check if the files in current directory has the RPATH variable defined
Using gentoo prefix portage I got in a situation where some packages did not contain the needed RPATH variable. This command helped me to find out which ones I should recompile

list block devices
Shows all block devices in a tree with descruptions of what they are.

Release memory used by the Linux kernel on caches
=1 --> to free pagecache =2 --> to free dentries and inodes =3 --> to free pagecache, dentries and inodes

Turn shell tracing and verbosity (set -xv) on/off with 1 command!
Running this command turns shell tracing and shell verbose debugging on or off. Not only does it do that, it also uses your terminals builtin method of setting colors to make debugging much easier. It looks at the current shell options contained in the $- special bash variable and that lets this function set the opposite of the current value. So from the shell you could do a: $ setx; echo "y" | ( cat -t ) | echo "d"; setx and it will turn on debbuggin. This is an amazingly useful function that is perfect to add system-wide by adding it to /etc/profile or /etc/bashrc.. You can run it from the shell, and you can also use it in your shell scripts like my .bash_profile - http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

gvim in full screen (execute again to toggle full screen on/off)
Only under linux. Requires Gvim compiled with "clientserver" functionality and wmctrl command installed on system. Instead of servername can be used the current edited file name. Put it in a function and map it for get rid of "Press a key" after execution.

Rips CDs (Playstation, etc.) and names the files the same as the volume name

move cursor to beginning of command line
Pressing Ctrl combined with 'a' will move the cursor to the beginning of the command under bash (other shells?). I used to do this after arrowing up for the last command, then typing 'sudo ' to run the last command as root, but of course the all time greatest command here `sudo !!` is more succinct. Still Ctrl+A can be very useful when you want to edit something at/close to the beginning of the command line.

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