Generate a password from the shell

genpasswd.sh

# Defined function for generating random password
genpasswd() {
	local l=$1
       	[ "$l" == "" ] && l=20
      	LC_CTYPE=C tr -dc A-Za-z0-9_ < /dev/urandom | head -c ${l} | xargs
}

NEW_PASSWORD=$(genpasswd 16)
echo $NEW_PASSWORD

# Alternate condensed form
NEW_PASSWORD=$(LC_ALL=C tr -dc 'A-Za-z0-9_' < /dev/urandom | head -c 16)
NEW_PASSWORD=$(LC_ALL=C tr -dc 'A-Za-z0-9%&()*+,-./:;<>?@[]^_{}~' </dev/urandom | head -c 16)
echo $NEW_PASSWORD

# Generate 5 random words
WORDS=5; LC_ALL=C grep -x '[a-z]*' /usr/share/dict/words | shuf --random-source=/dev/urandom -n ${WORDS} | tr '\n' ' ' | sed 's/ $/\n/'

# Alternate using uuidgen
NEW_PASSWORD=$(uuidgen)
echo "NEW_PASSWORD: ${NEW_PASSWORD}"

# Alternate using pwgen
NEW_PASSWORD=$(pwgen -A 16 1)
echo "NEW_PASSWORD: ${NEW_PASSWORD}"