CODEWITHSUNDEEP
c++clinuxterminalcommand-line-interface
Richard Octovianus
Richard Octovianus

Reputation: 180

What is the technique that the 'top' program uses to redisplay data on the screen?

As you probably know, when you run the "top" command in a terminal, it will show you the busiest processes on your computer and update the values periodically without adding a single line.

What is the technique called that allows it do this — to change the printed string from a CLI program?

Upvotes: 4

Views: 156

Answers (2)

Some programmer dude
Some programmer dude

Reputation: 409356

One way is to get the get the width/height of the terminal window, and just clear/print whole screen every time. Another way is to use VT100 escape codes to reposition cursor and overwrite whats on that position. A third way is to use a library such as ncurses.

Upvotes: 3

Michael Krelin - hacker
Michael Krelin - hacker

Reputation: 143219

Terminal accepts some control sequences for screen positioning, etc. Look into curses/ncurses library. Also, if you want to modify just one line you can do with just using \r and printing over that line again.

Upvotes: 2

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