A tiny, dependency-free CLI tool to print RFC-compliant UUID version 4 and 7 values in several textual formats.

The script is designed as a small, fast utility you can drop into your shell toolkit and use in scripts, pipelines, or ad‑hoc commands whenever you need fresh UUIDs.

1. UUID v4 (random) and UUID v7 (time-ordered, RFC 9562)
2. Multiple output styles:
   • hex (canonical 8-4-4-4-12 with hyphens),
   • simple (32 hex digits, no hyphens),
   • braced ({xxxxxxxx-...}),
   • urn (urn:uuid:...).
3. Uppercase or lowercase hex
4. Multiple UUIDs per invocation (-c/--count)
5. Custom separator (supports \n, \r, \t, \0, \\)
6. Optional suppression of the final trailing newline (-n/--no-newline)

• Python 3.8+ (system Python is sufficient)
• POSIX-like environment (Linux, macOS, WSL, etc.)

No third‑party Python packages are required!

Assuming you have cloned or downloaded the repository that contains print-uuid.py.

chmod +x print-uuid.py

You can now run it directly:

./print-uuid.py

By default, it prints a single UUID v4 in canonical hex form:

./print-uuid.py
# e.g. 0c9cf1f8-7a1e-4da2-8a26-1f8531f9b4c5

If you want a short, convenient command name (uuid), you can rename or link it into a directory on your PATH.

Option A: rename and move:

mv print-uuid.py uuid
chmod +x uuid
sudo mv uuid /usr/local/bin/

Option B: keep the filename and create a symlink:

chmod +x /path/to/print-uuid.py
ln -s /path/to/print-uuid.py ~/.local/bin/uuid

Make sure ~/.local/bin is included in your PATH.

Assuming the command is available as uuid.

uuid # prints a UUID v4
uuid 4 # prints a UUID v4 (explicit)
uuid 7 # prints a UUID v7
uuid v7 # same as: uuid 7

Example output:

$ uuid
f3f72236-2c9d-4f8a-9a8a-b10512e8c1fd

$ uuid 7
018f4e6c-5d8b-7c93-8f5b-63b198e03f47

uuid 7 -c 5
# prints 5 time-ordered UUID v7 values, one per line

# Canonical hex with hyphens (default)
uuid 7 -f hex

# Simple 32-hex format without hyphens
uuid 7 -f simple

# Braced format
uuid 7 -f braced
# e.g. {018f4e6c-5d8b-7c93-8f5b-63b198e03f47}

# URN format
uuid 7 -f urn
# e.g. urn:uuid:018f4e6c-5d8b-7c93-8f5b-63b198e03f47

uuid 7 --upper
# E.g. 018F4E6C-5D8B-7C93-8F5B-63B198E03F47

uuid 7 -f simple --upper
# E.g. 018F4E6C5D8B7C938F5B63B198E03F47

By default, UUIDs are separated by a newline (\n), and a final newline is printed at the end.

uuid 4 -c 3
# uuid1\nuuid2\nuuid3\n

You can customize the separator and optionally suppress the final newline:

# Comma-separated list of 3 UUIDs, no newline at the end
uuid 4 -c 3 -s ',' -n

# NUL-separated UUIDs (useful for low-level tooling)
uuid 4 -c 3 -s '\0' -n

# Windows-style CRLF between UUIDs
uuid 4 -c 2 -s '\r\n'

The separator string supports a few backslash escapes:

• \n – newline (LF)
• \r – carriage return (CR)
• \t – horizontal tab
• \0 – NUL byte
• \\ – a single backslash

Basic syntax:

uuid [version] [OPTIONS]

Where version is one of:

• 4 or v4 – UUID v4 (random, RFC 4122)
• 7 or v7 – UUID v7 (time-ordered, RFC 9562)

If omitted, version 4 is used.

UUID v4 values are generated using Python's built-in uuid.uuid4(), which uses cryptographically strong random numbers from the underlying OS.

UUID v7 is implemented according to RFC 9562:

• 48-bit Unix timestamp in milliseconds
• Version bits set to 0b0111
• Variant set to RFC 4122 (binary 10xxxxxx)
• Remaining bits filled from os.urandom()

The resulting UUIDs are time-sortable (their lexicographical order matches creation time), but strict monotonicity within the same millisecond is not required and not guaranteed.

• 0 – success
• 1 – usage error (for example, --count < 1)

In case of a usage error, a descriptive message is printed to stderr.

UUID=$(uuid 7 -f simple)
sed -e "s/@UUID@/$UUID/" template.conf > config.conf

uuid 4 -c 1000 > uuids.txt

uuid 4 -c 10 -s '\0' -n > uuids.bin
# now uuids.bin contains 10 NUL-separated UUIDs

This project is licensed under the MIT License.

Issues and pull requests are welcome. If you would like to propose new flags or behavior, please include concrete examples and a brief rationale so we can keep print-uuid small, understandable, and focused on its core job 😇