如何在 shell 中使用 .rar 压缩文件？

我需要通过 shell 解压缩不同类型的扩展，比如 .zip (p7zip-full), .rar (unrar-free)

但是对于相反的（压缩），我很难找到正确的命令。对于 RAR，它说没有候选人。

$ sudo apt install -y --install-recommends rar       
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package rar is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'rar' has no installation candidate

正如 p7zip-full 在安装时建议我安装 p7zip-rar

$ sudo apt install -y --install-recommends p7zip-full
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Suggested packages:
  p7zip-rar
The following NEW packages will be installed:
  p7zip-full
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 993 kB of archives.
After this operation, 3,943 kB of additional disk space will be used.

然后我也尝试安装它。

$ sudo apt install -y --install-recommends p7zip-rar 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package p7zip-rar is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'p7zip-rar' has no installation candidate

令人惊讶的是，它也没有候选人。

RAR 是一个私人扩展，这就是为什么很难找到合适的命令来压缩它的原因吗？如果是这种情况，那么我如何 .rar 压缩 shell 中的文件？

编辑：1 PS：回答@steeldriver，这里是我的sources.list 的状态

是否缺少多元宇宙参考？