====== PlayGround ======

===== Delete all lines beginning with a # from a file  =====

<code>
sed '/^#/d'
</code>
<code>
sed -i '/^#/d'
</code>

==== Remove From ssh known_hosts file ====
<code>
sed -i -n '/#/!p' /root/.ssh/known_hosts
</code>
===== Create Users Trash Bin ======

<code>
cd /to/folder
</code>
<code>
mkdir -m777 -v .Trash-$UID
</code>

<code>
chown $USER .Trash-$UID
</code>