jknife

juuid

UUID generator and parser tool.

Usage

juuid generate [options]    # generate UUIDs (alias: gen)
juuid parse <uuid>           # inspect a UUID

Examples

juuid gen
# 3f8a2c1e-9b4d-4e7a-8f2b-1c5d6e7f8a9b

juuid gen -n 5               # five UUIDs, one per line
juuid gen --upper            # uppercase
juuid gen -t 7               # UUIDv7: time sortable (RFC 9562)

juuid gen -t 7                                  # v7 generation
juuid parse "$(juuid gen -t 7)"                 # inspect what v7 contains
juuid parse 0190b5c0-6f7f-7a3e-8d2c-1f2e3a4b5c6d
# value: 0190b5c0-6f7f-7a3e-8d2c-1f2e3a4b5c6d
# version: 7
# variant: 2 (RFC 4122 / RFC 9562)
# timestamp: 2024-07-01T12:00:00Z

UUID v7

Version 7 UUIDs start with a 48 bit unix timestamp (milliseconds), followed by random bits. Two properties make them useful as database keys:

• sortable: v7 UUIDs created later compare greater — index friendly
• extractable timestamp: the creation time can be recovered from the UUID itself

Options (generate)

• -n, --count N number of UUIDs to generate (default: 1)
• -t, --type VERSION UUID version: 4 (random, default) or 7 (time sortable)
• --upper print uppercase UUIDs

Exit codes: 0 success, 2 error (invalid version, invalid count).

Install

brew tap mhus/jknife
brew install juuid

Or download the binary for your platform from the releases.

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