什么是tty终端？

水云间55

说是“控制终端”，具体是什么意思？在tty终端中可以有哪些操作？

zzj666

NAME
       tty - controlling terminal

DESCRIPTION
       The  file  /dev/tty  is        a character file with major number 5 and minor
       number 0, usually of mode 0666 and owner.group root.tty.         It is a  syn-
       onym for the controlling terminal of a process, if any.

       In  addition  to         the ioctl() requests supported by the device that tty
       refers to, the following ioctl() request is supported:

       TIOCNOTTY
              Detach the current process from its  controlling        terminal,  and
              remove  it  from its current process group, without attaching it
              to a new process group (that is, set its        process         group        ID  to
              zero).   This  ioctl()  call only works on file descriptors con-
              nected to /dev/tty; this is used by daemon processes  when  they
              are  invoked  by        a user at a terminal.  The process attempts to
              open /dev/tty; if the open succeeds, it detaches itself from the
              terminal        by  using  TIOCNOTTY,  while  if the open fails, it is
              obviously not attached to a terminal and does not need to detach
              itself.

FILES
       /dev/tty