centos7 switch graphic mode and text mode

In the graphic mode using ctrl + alt + F2 to switch to a text mode.
text mode press ctrl + alt + F2 to switch back to the graphic mode.
Enter the command init 3 to switch to text mode.
Enter the command init 5 to switch to graphic mode.

If ...

linux IO redirection

The default output device: standard output, STDOUT, 1

Default input device: standard input, STDIN, 0

Standard error output: STDERR, 2

Linux I/O redirection:

>: Override Output

eg. [root@mylab]# ls /var > /tmp/var2.out

>>: Append output

set -C: already prohibits the use of file redirection coverage

Force overwrite output ...