Paste the following code in  ~/.bashrc  :

#  vi  .bashrc

genpasswd() {

local l=$1

[ “$l” == “” ] && l=20

tr -dc A-Za-z0-9_ < /dev/urandom | head -c ${l} | xargs

}

 

Run it by typing  :

genpasswd  [no. of characters required]

Eg.  genpasswd  16

By default, if you do not specify the no. of characters, it will print 20 characters.

You can use this set as a password.