uuidv7gen.sh

#!/bin/sh
# -*- coding:utf-8 posix -*-
# === Initialize shell environment =============================================
#set -u                        # Just stop undefined values.
#set -e                        # Just stop error.
#set -x                        # Debug running command.

umask 0022
export LC_ALL=C
export LANG=C
PATH="$(command -p getconf PATH 2>/dev/null)${PATH+:}${PATH-}"
case $PATH in (:*) PATH=${PATH#?};; esac
export PATH # or PATH="<add dir>${PATH+:}${PATH-}"
export UNIX_STD=2003          # to make HP-UX conform to POSIX

# === Define the functions for printing usage and error message ================
usage_and_exit(){
    cat <<-"USAGE" 1>&2

# About

The uuidv7gen.sh generate UUIDv7. This script only handles the case where
rand_a and rand_b are random numbers.

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                           unix_ts_ms                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          unix_ts_ms           |  ver  |       rand_a          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|var|                        rand_b                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                            rand_b                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

# Usage

## Command

uidv7gen.sh [Options] [--msec <ms>] [-d <delimiter>]

```
$> uuidv7gen.sh
01904a37-df30-789e-8b43-e83a9718cc28
```

```
$> ./uuidv7gen.sh -d "_" | tr "abcdef" "ABCDEF"
01904A3B_B790_7A32_DC8E_5C5C7B12863C
```

```
$> i=0; while [ 5 -gt $i ] ; do i=$(( i + 1 )); ./uuidv7gen.sh --msec 178598740350$i; done
019fd525-0eed-74fd-c04a-1e529e726fec
019fd525-0eee-7519-8e1b-3e08ef286c33
019fd525-0eef-712a-e8e8-4788c5a537eb
019fd525-0ef0-7a41-de69-cc3363c7a516
019fd525-0ef1-7e31-d01e-1e55043e7a92
```

## Options

+ -h |--help |--version
  - help.
+ --msec <ms>
  - Generating at <ms>.

# Version

2024-06-25T23:10:00 0.01 [Latest](https://gist.github.com/search?q=user%3Atd-shi+filename%3A.sh+uuid)

# LICENSE

[CC0(Public domain)](https://creativecommons.org/publicdomain/zero/1.0/legalcode)

# Author

2024 TD

USAGE

    exit 1
}

error_exit() {
    ${2+:} false && echo "${0##*/}: $2" 1>&2

    exit "$1"
}

# === Initialize parameters ====================================================
TIME=0
DELI="-"

# === Confirm that the required commands exist =================================
if type hexdump >/dev/null 2>&1 ; then
    genRandom () {
        hexdump -n 16 -e '8/2 " %04x" "\n"' -v /dev/urandom | tr -d " "
    }
elif type od >/dev/null 2>&1 ; then
    genRandom () {
        od -A n -t x2 -N 16 -v /dev/urandom | tr -d " "
    }
else
    error_exit 1 'require command "hexdump" or "od"'
fi
type od >/dev/null 2>&1 || error_exit 1 'require command od'

# === Print usage and exit if one of the help options is set ===================
case "$# ${1:-}" in
    ('1 -h'|'1 --help'|'1 --version') usage_and_exit;;
esac

# === Read options =============================================================
while :; do
    case "${1:-}" in
        (--|-)
            break
            ;;
        (--msec)
            TIME=$(printf '%s' "${2:-}" | tr -Cd "0123456789")
            shift 2
            ;;
        (--delimiter|-d)
            DELI=$(printf '%s' "${2:--}")
            shift 2
            ;;
        (--*|-*)
            error_exit 1 'Invalid option'
            ;;
        (*)
            break
            ;;
    esac
done

# === Require parameters check =================================================
# === Last parameter ===========================================================
# === Define funcitons =========================================================
unixTimeSec () {
    set -- "$(date -u "+%Y-%m-%d %H:%M:%S")" "$1"
    set -- "${1%% *}" "${1##* }" "$2"
    set -- "${1%%-*}" "${1#*-}" "${2%%:*}" "${2#*:}" "$3"
    set -- "$1" "${2%%-*}" "${2#*-}" "$3" "${4%%:*}" "${4#*:}" "$5"
    set -- "${1}" "${2#0}" "${3#0}" "${4#0}" "${5#0}" "${6#0}" "$7"
    [ "$2" -lt 3 ] && set -- $(($1 - 1)) $(($2 + 12)) "$3" "$4" "$5" "$6" "$7"
    set -- $(( (365 * $1) + ($1 / 4) - ($1 / 100) + ($1 / 400))) $(( (306 * (1 + $2) / 10) - 428 )) "$3" "$4" "$5" "$6" "$7"
    set -- $(( ($1 + $2 + $3 - 719163) * 86400 + $4 * 3600 + $5 * 60 + $6 )) "$7"
    printf "%s%s" "$1" "$2"
}

decode2Hex () {
    set -- "$1" "0" ""
    while [ "$1" -gt 0 ] ; do
        set -- "$(( $1 / 16))" "$(( $1 % 16 ))" "$3"
        set -- "$1" "$2" "\\0$(( ($2>>3) + 6))$(($2 & 0x7))$3"
    done
    printf "$3" | tr ":;<=>?" "abcdef"
}

# === Main routine =============================================================
if [ "_" != "_${TIME}" ] && [ "${TIME}" -gt 0 ]; then
    :
else
    TIME=$(unixTimeSec "000")
fi

set -- "0000000000000$(decode2Hex "${TIME}")" "$(genRandom)"
set -- "${1#${1%????????????}}" "${2#${2%????????????????????}}" # 12, 20
set -- "${1%????}" "${1#????????}" "${2%??????????}" "${2#??????????}"
set -- "${1}" "${2}" "7${3%???????}" "${3#???}" "${3#????}" "${3#????????}${4%?????}${4#?????}"
set -- "${1}" "${2}" "${3}" "$(echo "${4%??????}" | tr "01234567" "89abcdef")" "${5%???}" "${6}"

printf "%s\n" "${1}${DELI}${2}${DELI}${3}${DELI}${4}${5}${DELI}${6}"

# === End shell script =========================================================
exit 0