Revisions to Linux: Difference between /dev/console, /dev/tty and /dev/tty0

Change link to html formatted one (instead of txt)

edit approved Feb 14, 2023 at 10:13

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From the Linux Kernel documentation on Kernel.org Linux Kernel documentation on Kernel.org:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server.

Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

From the Linux Kernel documentation on Kernel.org:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server.

Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

From the Linux Kernel documentation on Kernel.org:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server.

Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

just added a more descriptive link for accessibility and broke up a large block of text :) great answer!

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edit approved Sep 19, 2020 at 17:48

Robert Houghton

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1
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From the documentationLinux Kernel documentation on Kernel.org:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server. Now

Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

From the documentation:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server. Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

From the Linux Kernel documentation on Kernel.org:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server.

Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

fix link

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edited Nov 30, 2018 at 23:01

user313992

From the documentation documentation:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server. Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

From the documentation:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server. Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.

You can see that tty is the console where process starts, and tty0 is a always current console.

From the documentation:

/dev/tty Current TTY device /dev/console System console /dev/tty0 Current virtual console

In the good old days /dev/console was System Administrator console. And TTYs were users' serial devices attached to a server. Now /dev/console and /dev/tty0 represent current display and usually are the same. You can override it for example by adding console=ttyS0 to grub.conf. After that your /dev/tty0 is a monitor and /dev/console is /dev/ttyS0.

An exercise to show the difference between /dev/tty and /dev/tty0:

Switch to the 2nd console by pressing Ctrl+Alt+F2. Login as root. Type sleep 5; echo tty0 > /dev/tty0. Press Enter and switch to the 3rd console by pressing Alt+F3. Now switch back to the 2nd console by pressing Alt+F2. Type sleep 5; echo tty > /dev/tty, press Enter and switch to the 3rd console.