查看linux系统版本及内核版本

查看linux版本:
$ lsb_release -a
No LSB modules are available.
Distributor ID:    Ubuntu
Description:    Ubuntu 20.04 LTS
Release:    20.04
Codename:    focal

查看内核版本：
$ uname -a
Linux 09bdbc04d3b0 5.4.0-67-generic #75-Ubuntu SMP Fri Feb 19 18:03:38 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
$ uname -r
5.4.0-67-generic
$ cat /proc/version
Linux version 5.4.0-67-generic (buildd@lcy01-amd64-025) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #75-Ubuntu SMP Fri Feb 19 18:03:38 UTC 2021