Thread: Limiting printf area

What you want to do can only be done using a non-standard library like ncurses. It cannot be done using just printf().

C is older than both of those. It does allow it, there's just no standard way to do it, because there are no "standard" screens or terminals.


Quzah.

Originally Posted by nowber

Hello! Suppose I draw a frame round the screen, using ascii table symbols and the next thing I want to do is printf different text, of course limiting the area, so that my text wouldn't be printed across these frame borders. Is it possible in C to tell to print everything within some limits? Surely gotoxy at each printf isn't the solution?

Sometimes, people ask "Why use that old Turbo C/C++ ?", and I just smile:

Code:

window   Defines active text-mode window.

 Syntax:
   void window(int left, int top, int right, int bottom);

The top left corner of the screen is (1,1).

 Prototype in:
 conio.h

 Remarks:
window defines a text window onscreen. If the coordinates are in any way
invalid, the call to window is ignored.

 þ left and top are the screen coordinates
   of the upper left corner of the window.

 þ right and bottom are the screen
   coordinates of the lower right corner.

   The minimum size of the text window is one
   column by one line. The default window is
   full screen, with these coordinates:

 þ 80-column mode:    1,1,80,25
 þ 40-column mode:    1,1,40,25

 Return Value: None.

 Portability:
window works with IBM PCs and compatibles only.

A corresponding function exists in Turbo Pascal.

 See Also:
  clreol    delline        gotoxy     puttext
  clrscr    gettextinfo    insline   textmode

 Example:
 #include <conio.h>

 int main(void)
 {

    window(10,10,40,11);
    textcolor(BLACK);
    textbackground(WHITE);
    cprintf("This is a test\r\n");

    return 0;
 }

Note that Turbo C ver. 1.01 had "int main()", before K&R's "The C Programming Language".

Lacking conio.h's help, you can still print inside a window, just as you can print up any columns, in C.

You just need variables for things like lmargin, rmargin, toprow, botrow, to define the left margin, right margin, top row, bottom row, etc.

So in a function, you send it the address of your char array you want printed, and it will handle it from there. It's not as nice as window, but it can be done easily.

Originally Posted by Adak

Turbo C nonsense

Or you can just use ncurses. This gives you the added benefit of using a real, working compiler at the same time. If you are running on Windows, then pdcurses should do it.

Originally Posted by Adak

Sometimes, people ask "Why use that old Turbo C/C++ ?", and I just smile:

Or you could just use Pascal!


Quzah.