10 Ways to Generate a Random Password from the Command Line
( http://www.howtogeek.com/howto/30184/10-ways-to-generate-a-random-password-from-the-command-line/ )


e.g.

date +%s | sha256sum | base64 | head -c 32 ; echo  # only 32 chars

< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c${1:-32};echo;  # only 32 chars

date | md5sum   # use whole pw for security reasons