Generate UUID v7

Generate a Unix timestamp-based UUID v7 with millisecond precision, ideal for database primary keys.

Code

Utilities

t=$(date +%s%3N)
r=$(od -An -tx1 -N10 /dev/urandom | tr -d ' \n')
printf '%08x-%04x-7%s-%04x-%s\n' \
  $(( t >> 16 )) \
  $(( t & 0xffff )) \
  "${r:0:3}" \
  $(( (0x${r:3:4} & 0x3fff) | 0x8000 )) \
  "${r:7:12}"

Server

More Bash Snippets

Generate UUID v1

Generate a time-based UUID v1 using timestamp and random node ID.

Generate UUID v3

Generate a name-based UUID v3 using MD5 hashing of namespace and name.

Generate UUID v4

Generate a random UUID v4 (Universally Unique Identifier).

Generate UUID v5

Generate a name-based UUID v5 using SHA-1 hashing of namespace and name.

Generate UUID v6

Generate a reordered time-based UUID v6 with improved sortability for databases.

Array Difference

Find elements in the first array that are not present in the second array.