Is there a "proper" way of clearing a screen in C for a console application?
(Besides using:system("cls"))
views:
570answers:
6
+2
A:
Well, C doesn't understand the concept of screen. So any code would fail to be portable.
Maybe take a look at conio.h or curses, according to your needs?
Portability is an issue, no matter the library used.
Tom
2010-02-27 15:20:20
I +1'd you before reading your line about conio.h. Note that, too, is highly non-portable.
Derrick Turk
2010-02-27 17:05:17
I´ve added curses link
Tom
2010-02-27 17:09:48
I'm not sure about conio.h, but it looks like curses takes care of the GUI in a more comprehensive way than I was initially imagining. I'll have to look into this. Thanks for the suggestion!
dvrok
2010-03-01 02:12:11
A:
The proper way to do it is by using tput or terminfo functions to obtain terminal properties and then insert newlines according to the dimensions..
Jack
2010-02-27 15:22:55
Huh?! Assuming the terminfo call was successful, and the terminal type is a smart (not 'dumb' or 'tty') then you might as well use a terminfo (or termcap) clear screen instruction (clear / cl), rather than pushing multiple newlines, which can be slow on larger X-Window terminals, particularly across networks.
mctylr
2010-02-28 01:06:06
+3
A:
Since you mention cls, it sounds like you are referring to windows. If so, then this KB item has the code that will do it. I just tried it, and it worked when I called it with the following code:
cls( GetStdHandle( STD_OUTPUT_HANDLE ));
Mark Wilkins
2010-02-27 16:01:28
+1 although i didnt ask, but this can be quite useful. And what can be done on unix to 'clear'?
N 1.1
2010-02-27 16:30:22
@nvl: I only have windows machines at home, and takes about 15 usernames and passwords to log into work machines from here, so I can't test it right now. But I believe ncurses is the route for that (http://linux.die.net/man/3/ncurses).
Mark Wilkins
2010-02-27 17:45:08
I was actually thinking in terms of Unix-based systems - but this helps for Windows. Thanks!
dvrok
2010-03-01 02:13:15
A:
Windows:
system("cls");
Unix:
system("clear");
You could instead, insert newline chars until everything gets scrolled, take a look here.
With that, you achieve portability easily.
Wilhelm
2010-02-27 17:39:06
A:
There is no C portable way to do this. Although various cursor manipulation libraries like curses are relatively portable. conio.h is portable between OS/2 DOS and Windows, but not to *nix variants.
The entire notion of a "console" is a concept outside of the scope of standard C.
If you are looking for a pure Win32 API solution, There is no single call in the Windows console API to do this. One way is to FillConsoleOutputCharacter of a sufficiently large number of characters. Or WriteConsoleOutput You can use GetConsoleScreenBufferInfo to find out how many characters will be enough.
You can also create an entirely new Console Screen Buffer and make the the current one.
John Knoeller
2010-02-28 00:41:47