uuid -v4 和 uuidgen 有什么区别？

Question

我正在为 githooks 创建一些 Jenkins 令牌，我正在使用 uuidgen。

我的同事说他们通常使用 uuid -v4，在 sudo apt-get-ing uuid 之后，uuid -v4 和 uuidgen 看起来是一样的：

$ uuid -v4
832dce77-ddec-4cc5-9872-47a81456653f
$ uuidgen
a321bc87-a1b5-4cc5-b6b5-feaf3a610ab8

供参考：我是运行这个 Ubuntu。

它们有什么区别？他们是一样的吗？

Answer 1

tldr；它们都是随机的，因为 uuidgen == uuidgen -r == uuid -v4

man 1 uuidgen 并没有这么说，但是 uuidgen -t 和 uuidgen -r 分别生产版本 1 ("time and node based") 和版本 4 ("random data based") ISO/IEC 11578:1996.

规定的 UUID

$ { uuidgen -t && uuidgen -r && uuid -v1 && uuid -v4 ; } | xargs -L1 uuid -d

encode: STR:     5f441c74-c63a-11e7-8cb0-0242ac110002
        SIV:     126630312945231364299766443008257490946
decode: variant: DCE 1.1, ISO/IEC 11578:1996
        version: 1 (time and node based)
        content: time:  2017-11-10 17:12:46.679154.0 UTC
                 clock: 3248 (usually random)
                 node:  02:42:ac:11:00:02 (local unicast)
encode: STR:     d70f042a-c5ca-4726-b259-795e47fd1b95
        SIV:     285861988065069261246745478758429170581
decode: variant: DCE 1.1, ISO/IEC 11578:1996
        version: 4 (random data based)
        content: D7:0F:04:2A:C5:CA:07:26:32:59:79:5E:47:FD:1B:95
                 (no semantics: random data only)
encode: STR:     5f443b5a-c63a-11e7-8cd2-0242ac110002
        SIV:     126630939639996852130686378090112811010
decode: variant: DCE 1.1, ISO/IEC 11578:1996
        version: 1 (time and node based)
        content: time:  2017-11-10 17:12:46.679945.0 UTC
                 clock: 3282 (usually random)
                 node:  02:42:ac:11:00:02 (local unicast)
encode: STR:     09432e97-a1fc-4e05-9492-7c0c11ec0abc
        SIV:     12311880856012488273304867468361861820
decode: variant: DCE 1.1, ISO/IEC 11578:1996
        version: 4 (random data based)
        content: 09:43:2E:97:A1:FC:0E:05:14:92:7C:0C:11:EC:0A:BC
                 (no semantics: random data only)

参考文献：

uuid -v4 和 uuidgen 有什么区别？

What is the difference between uuid -v4 and uuidgen?

uuid