Ubuntu – How to launch GUI app (in Ctrl+Alt+F7) from tty (Ctrl+Alt+F1-F6)

You can either:

press ctrl+alt+F7 *

Or

run the command startx

* From the 17.10 Release Notes:

• GDM has replaced LightDM as the default display manager. The login screen now uses virtual terminal 1 instead of virtual terminal 7.

Also see Why is my GDM at a different TTY than my desktop environment? for more about the origin of this change.

this gui is pts/0

Um, nope. I'm not sure where you got pts/0 from, but that's an X server started from the tty1, it isn't pts/0. See this U&L post for more.

At any given time, by default, there are 6 TTYs with getty running on them (so that you can login there) - TTYs 1-6, which you can access using CtrlAltF1-F6. TTY 7 has the GUI started by default. On 16.04 and above, you can start more getty instances using:

systemctl start getty@ttyN

Replacing N with an appropriate number.

To find the number of pseudoterminals currently open, you can do:

ps -eo tty= | sort -u

ps -e lists all processes, and -o tty= lists the process TTYs without a header line. sort and get unique entries with -u. For example:

$ ps -eo tty= | sort -u
?
pts/0
pts/1
pts/2
tty1
ttyS0