466

Using the clear command on the terminal only fools the user into thinking the screen has been cleared...you can still see output from the previous commands when you scroll using the mouse. This makes life difficult when you are drowning in a tsunami of text.

Various solutions (escape code etc.) which can be found on the Internet are only variations of what the clear command already does.

So how do you clear the contents of a terminal in Linux for real?

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10
  • 49
    I'd categorize this as "software tools commonly used by programmers" (mentioned in the FAQ as valid). Commented Mar 20, 2011 at 6:18
  • 5
    What you're really asking is "How can I clear the terminal's scroll-back buffer?" which is independent of the shell (Bash) or Ubuntu. Commented Mar 20, 2011 at 11:23
  • @spiderplant0 probably because AskUbuntu is the right place for this -- at this time. Didn't exist when this was asked, so it got closed as off topic, even though that isn't the case. Commented Mar 14, 2013 at 15:16
  • 1
    That's a more general question, affecting not only Ubuntu or bash, as @Dennis noted. I'd change the topic "Clear the Ubuntu bash screen for real" --> "Clear a terminal screen for real" Commented Apr 11, 2016 at 14:54
  • There are many different terminal types with which you can run Bash (the term "bash terminal" is meaningless). "Clearing" isn't applicable to all of them - sometimes, the nearest approximation is to tear the paper and bin/shred/burn/destroy the bit you don't want. Commented Jul 4, 2018 at 12:24

12 Answers 12

Reset to default
577

Use the following command to do a clear screen instead of merely adding new lines ...

printf "\033c"

yes that's a 'printf' on the bash prompt.

You will probably want to define an alias though...

alias cls='printf "\033c"'

Explanation

\033 == \x1B == 27 == ESC

So this becomes <ESC>c which is the VT100 escape code for resetting the terminal. Here is some more information on terminal escape codes.

Edit

Here are a few other ways of doing it...

printf "\ec" #\e is ESC in bash
echo -en "\ec" #thanks @Jonathon Reinhart.
# -e    Enable interpretation of of backslash escapes
# -n    Do not output a new line

KDE

The above does not work on the KDE console (called Konsole) but there is hope! Use the following sequence of commands to clear the screen and the scroll-back buffer...

clear && echo -en "\e[3J"

Or perhaps use the following alias on KDE...

alias cls='clear && echo -en "\e[3J"'

I got the scroll-back clearing command from here.

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17 Comments

This is actually terminal specific. "\033c" is ESC c which is the VT-XXX escape sequence for "Full Reset (RIS)". Almost all terminals people actually use these days are VT compatible, but if you ever find yourself using a weird terminal, this might not work. @vpit3833's answer is more likely to work assuming TERM is set correctly.
printf is a Bash builtin (it's true that it's also a separate binary, but builtins have precedence and most modern shells have printf).
@SDX2000 OK ... I know you specified Ubuntu, and I assumed that these would behave similar on all "modern" terminal emulators. I initially tested on my MAC's terminal and it did not reset there, but it did reset on my Centos Linux.
$0.02 a few years later, but i'm a student at CU. Asked my operating systems professor and he said this was an example of ANSI escape sequence: en.wikipedia.org/wiki/ANSI_escape_code This is an example of in-band signalling.
Worked perfectly on Linux. Didn't clear the scrollback on macOS.
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242

Try reset. It clears up the terminal screen but the previous commands can be accessed through arrow or whichever key binding you have.

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8 Comments

Thanks! But it clears every thing including the prompt. See my answer for a solution which doesn't do this.
@SDX2000 Both clear the prompt, and then the shell generates a new one. The one disadvantage to reset is that it seems to be a bit slower (probably because it does more than just emit ESC c) but it's more portable.
@Laurence thanks for the clarification...I tried reset but it was so slow that I assumed the prompt was cleared along with everything else. I will still prefer to use ESC c since I will probably never use any terminal other than the one Ubuntu uses. Though reset may come in handy someday when I am debugging a remote machine through the serial port etc.
@SDX2000 reset is also handy for those cases where your terminal gets badly mangled because you killed something (or catted a binary file) and it left your term in a mangled state. Ever get into a state where your prompt shows up but not your typing, and when you hit enter the new prompt shows up next to the previous prompt rather than below it? reset fixes that. That's actually all I ever use it for... I've never had a need/desire to clear my scroll-back buffer.
The one-second delay associated with reset is unbearable for me.
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82 
tput reset

That will do the trick!

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2 Comments

Executes much faster than plain reset, but still does the job!
Explanation of why it is faster: Why does the reset command include a delay?
13

  1. Clean the visible screen

     clear

  2. Clean screen and clear buffer

     clear && clear

  3. Clean and 1-sec delay

     reset

  4. Clean without 1-sec delay

     tput reset
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1 Comment

This answer is the best by far. It should be marked as the answer.
10

None of the answers I read worked in PuTTY, so I found a comment on this article:

In the settings for your connection, under "Window->Behavior" you'll find a setting "System Menu Appears on ALT alone". Then CTRL + L, ALT, l (that's a lower case L) will scroll the screen and then clear the scrollback buffer.

(relevant to the OP because I am connecting to an Ubuntu server, but also apparently relevant no matter what your server is running.)

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1 Comment

Also, given that in the "Window" settings of PuTTY you activated the "System menu appears on ALT-Space" you can rapidly do CTRL+L then ALT+Space, U which first clears the terminal window then resets the scrollback for real.
7

My favorite human friendly command for this is:

reset

Tested on xterm and VT100. It also helps after an abnormal program termination. Keeps the command buffer, so up-arrow will cycle through previous commands.

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7

The following link will explain how to make that alias permanent so you don't have to keep typing it in.

https://askubuntu.com/questions/17536/how-do-i-create-a-permanent-bash-alias

These are the steps detailed at that link.

  1. vim ~/.bashrc or gedit ~/.bashrc or what ever text editor you like
  2. put alias cls='printf "\033c"' at the bottom of the file
  3. save and exit
  4. . ~/.bashrc (and yes there should be a space between . and ~)
  5. now check to see if everything worked!

I take no credit for this information just passing it along.

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1 Comment

\033c is same thing as \x1bc, and \x1bc is the same thing as \u001bc. All three of those work!
6

I know the solution employing printing of new lines isn't much supported, but if all else fails, why not? Especially where one is operating in an environment where someone else is likely to be able to see the screen, yet not able to keylog. One potential solution then, is the following alias:

alias c="printf '\r\n%.0s' {1..50}"

Then, to "clear" away the current contents of the screen (or rather, hide them), just type c+Enter at the terminal.

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3 Comments

My terminal is for some reason unable to clear scrollback history, none of these solutions work except just printing a bunch of newlines, I would just suggest a clear at the end so to reset the cursor back at the top though.
@MaximilianBallard which TTY is this?
st terminal, but I don't know if its the specific terminal itself as it doesn't have this issue on my other computer and I use the same one.
6

Just to add that tmux scroll buffer does not clear with clear, reset or printf. You need to :clear-history. See link.

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3

With KDE and Ubuntu 12.04 LTS and the "Konsole" terminal, none of the posted answers work. However, pressing default keyboard shortcut CTRL+Shift+X does work! Source:

https://bugs.kde.org/show_bug.cgi?id=288913

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1 Comment

This has been changed to CTRL+Shift+K in later KDE versions: bugs.kde.org/show_bug.cgi?id=282593
-2 
echo -e "\e[3J"

This works in Linux Machines

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1 Comment

Though we thank you for your answer, it would be better if it provided additional value on top of the other answers. In this case, your answer does not provide additional value, since another user already posted that solution. If a previous answer was helpful to you, you should vote it up instead of repeating the same information.
-59

Compile this app.

#include <iostream>
#include <cstring>

int main()
{
  char str[1000];
  memset(str, '\n', 999);
  str[999] = 0;
  std::cout << str << std::endl;
  return 0;
}
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5 Comments

Sorry, but this isn't the best solution. There are better methods than spewing 999 newlines
There actually is some value to this. In some terminals, clearing the screen with the other methods will kill the history and not allow you to scroll back... although with 999 lines my finger would get tired. Poor guy.
@JoshuaDavid The whole point of the question was that OP did not want to be able to scroll back after clearing.
@Socowi My comment was addressing this -50 poorly-rated answer, not the OP. But you're right!
I daren't post this as an answer, but you could do something like this in bash with head -c999 /dev/zero | tr '\0' '\n', or yes '' | head -999

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