pnoutrefresh(p,0, 0, 0, 0, 23,19); pnoutrefresh(p,24, 0, 0,24,23,43); pnoutrefresh(p,48, 0, 0,48,23, 67); doupdate();

The pnoutrefresh() functions update portions of the pad p to various locations on the standard screen. The final doupdate() function updates the screen with the information.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 #include <ncurses.h> int main(void) { WINDOW *pad; int a; initscr(); pad = newpad(40,100); if(pad == NULL) { endwin(); puts( Problem creating pad ); return(1); } for(a=0;a<4000;a++) { waddch(pad, A + (a % 26)); } prefresh(pad,0,0,7,30,17,50); wgetch(pad);

25 26 27 28 29 30 31 32 33

mvwaddstr(pad,1,0, Hello, there! ); pnoutrefresh(pad,0,0,7,30,17,50); doupdate(); wgetch(pad); endwin(); return 0; }

Sample output: The output is the same as shown for prefresh() below, though after pressing the Enter key, the text Hello, there! appears on the second line.

newpad(), prefresh(), doupdate(), wnoutrefresh()

prefresh()

Pads work like windows, though they re not displayed on the screen. To see the information put to a pad, the prefresh() function is used. Unlike the refresh() function, prefresh() takes a rectangle of text (and attributes) from the pad and places it in a window. This is how information from a pad is displayed.

int prefresh(WINDOW *pad, int pminrow, int pmincol, int sminrow, int smincol, int smaxrow, int smaxcol);

pminrow and pmincol are int values represents the upper-left (Y and X) coordinates of a rectangle of text on the pad. sminrow and smincol are int values representing the upper-left (Y and X) coordinates of a rectangle of text on the standard screen. This location is where the text from the pad will be placed. smaxrow and smaxcol represent the lower-right (Y and X) coordinate of the rectangle on the standard screen. These are int values and they are relative to the home location, not to sminrow and smincol. The differences between the upper-left and lower-right coordinates on the screen are also used to calculate the size of the rectangle copied from the pad.

prefresh() always outputs text to the standard screen. The prefresh() function updates the standard screen; there is no need to call refresh() after prefresh() to see the text. You cannot prefresh() a rectangle from the pad that is larger than the standard screen (or larger than the pad, for that matter).

prefresh(p,0,0,0,0,10,35);

The statement here places part of the pad p on the standard screen. The text from the pad starts at location 0, 0. The rectangle on the standard screen starts at location 0, 0, and it is 10 rows deep by 35 columns wide.

prefresh(psto,py,px,10,5,11,75);

Here, text from the pad psto is read from starting location py, px, and placed on the screen at location 10, 5. The rectangle is 1 row high and 70 characters wide.

1 2 3 #include <ncurses.h> int main(void)

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 {

WINDOW *pad; int a; initscr(); pad = newpad(40,100); if(pad == NULL) { endwin(); puts( Problem creating pad ); return(1); } for(a=0;a<4000;a++) { waddch(pad, A + (a % 26)); } prefresh(pad,0,0,7,30,17,50); wgetch(pad); endwin(); return 0; }

The sample output is shown in Figure A-9.

11, newpad()

printw()

The printw() function is the NCurses equivalent to the standard C printf() function. Use printw() in your NCurses programs when you need printf().

int int int int int int printw(const char *fmt, ...); wprintw(WINDOW *win, const char *fmt, ...); mvprintw(int y, int x, const char *fmt, ...); mvwprintw(WINDOW *win, int y, int x, const char *fmt, ...); vw_printw(WINDOW *win, const char *fmt, va_list varglist); vwprintw(WINDOW *win, const char *fmt, va_list varglist);