Execute each command in terminal from top line / Execute clear before each command

Question

I would like to ask if it is possible to set up in bash so that each command is executed from of the top of terminal window. In other words if it is possible to execute clear before each command.

Also I wonder if it is possible to do this without using preexec() hook since I have history disabled anyway in bash.

Out of interest, why would you want to do this? Any command with any kind of output would be moot, e.g. `ls`. — Sparhawk, Mar 14 '17 at 02:23
Put `^[[2J^[[;H` at the beginning of `PS1`, and bask in the inability to see the output of any of your commands. (Note: `^[` indicates a literal Escape) — DopeGhoti, Mar 14 '17 at 02:35
Not exactly the same, but related and more useful: [Keep bash input on top line of screen](https://unix.stackexchange.com/questions/218323/keep-bash-input-on-top-line-of-screen) — Gilles 'SO- stop being evil', Mar 14 '17 at 23:35

Leonardo Gomes G. Avellar · Answer 1 · 2017-07-30T07:01:50.047

0

You could do this on your bashrc:

export PROMPT_COMMAND="clear; $PROMPT_COMMAND"

According to the Bash manual:

PROMPT_COMMAND

If set, the value is interpreted as a command to execute before the printing of each primary prompt ($PS1).

So every time you press Enter to commit a command, Bash will clear the screen for you after executing the command. You won't be able to see the output of your commands though.

edited Jul 30 '17 at 07:01

answered Jul 30 '17 at 06:24

Leonardo Gomes G. Avellar

9
3

No, OP wants to clear before command to be executed so output and the command itself must be there, not after commands got executed immediately clear the screen! – αғsнιη Jul 30 '17 at 06:48
Hmm, yeah I got it all wrong. The event to clear the screen would be, "as soon as I start typing, the screen is cleared", or something like that? – Leonardo Gomes G. Avellar Jul 30 '17 at 06:57
see this Q&A https://unix.stackexchange.com/q/44713/72456 – αғsнιη Jul 30 '17 at 07:39
OP doesn't want to use the preexec. preexec would be my primary answer. – Leonardo Gomes G. Avellar Jul 30 '17 at 09:17
S/he can refer to another two answers : ) – αғsнιη Jul 30 '17 at 09:30

Execute each command in terminal from top line / Execute clear before each command

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