Crystal lang 进程是否可以更改其用户 (euid/uid)?

Is it possible for a Crystal lang process to change it's user (euid/uid)?

如果 Crystal 语言进程是 运行 作为根,它可以将它的 euid/uid 更改为其他东西吗?例如:

 old_euid, old_ui = Process.euid, Process.uid
 Process.euid = someone_else
 Process.uid  = someone_else

是的,通过使用 libc 的绑定:

lib LibC
  fun setuid(uid_t : Int)
  fun getuid : Int
end

LibC.getuid                         #=> 0
Process.run("whoami", output: true) #=> root

LibC.setuid(uid)
LibC.getuid                         #=> my uid
Process.run("whoami", output: true) #=> my user name

程序当然需要 运行 作为根(即 sudo crystal source.cr