Generate random value
mktemp -u XXXXXXXX │
luVXd5ka
# length by number value
mktemp -u $(printf 'X%.0s' $(seq 1 24))
XxClYUWZ1IQKHwMCWDi09RTz
Generate 10 items value:base64
for i in {1..10}; do val=$(head -c 1024 /dev/urandom | tr -dc 'A-Za-z0-9' | head -c 24); \
echo "$val:$(echo -n "$val" | base64)"; done