Odtnhj

I recently was studying ncurses and a doubt just hit me: What EXACTLY does the refresh function does?

I searched a little about it, read some tutorials and even a documentation and my conclusion was that it "refreshes" the actual screen with the format done on the "buffer screen" (it just updates the output on the screen).

Doing some tests I clearly realized I was wrong since the output appeared with and without the refresh function! Below there's a simple program I did just to test it and I can't realize the actual functionality of this function.

#include <ncurses.h>
#include <string.h>

int main() 
 char mesg = "Just a String";
 int row, col;

 initscr();
 getmaxyx(stdscr, row, col);

 while(true) 
 refresh();
 mvprintw(row/2, (col - strlen(mesg))/2, "%s", mesg);

 mvprintw(row-2, 0, "This screen has %d rows and %d columnsn", row, col);

 char c = getch();
 if (c == 'e') row++; 
 else if (c == 'q') row--; 
 else if (c == 'a') col--; 
 else if (c == 'd') col++; 
 

 getch();
 endwin();

 return 0;

I moved the refresh all over the program, I removed it and nothing seems to change. What exactly it does??

The getch function calls refresh, which is probably confusing you as you move the explicit call for refresh to different places.

Curses functions write to a virtual screen (i.e., not real) and refresh updates the physical screen (the real one) by comparing the two and making small changes (if possible).