如何为ncurses添加持久性？

Question

PROBLEM

I would like to add persistence to a ncurses program: write the last displayed screen to disk on exit, read that last displayed screen back from disk on entry . If possible, include the background and foreground colors.

QUESTION

1. Is there a way to read the entire block of text from ncurses that appears in a NWindow or NPanel or will I have to maintain my own buffer and essentially write/read twice (to my buffer and to ncurses)?
2. Same question for COLOR_PAIR information.

ANSWER

Rici's answer below is perfect, but I had to experiment a little to get the call orders right.

USAGE

The code below actually works great for saving and restoring color.

• Run it once without arguments to write out a screen dump file /tmp/scr.dump .
• Run it again with the argument read to read from the file.

CODE

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

void print_in_middle(WINDOW *win, int starty, int startx, int width, char *string);
int main(int argc, char *argv[])
{

   bool read_mode = ( argc>1 && !strcmp( argv[1], "read" ));

   initscr();          /* Start curses mode        */

   if(has_colors() == FALSE)
   {
       endwin();
       printf("Your terminal does not support color\n");
       return 1;
   }
   start_color();              /* Start color          */
   use_default_colors();   // allow for -1 to mean default color
   init_pair(1, COLOR_RED, -1);

   if ( read_mode )
   {
       refresh();
       if ( scr_restore( "/tmp/scr.dump" )!=OK )
       {
           fprintf( stderr, "ERROR DURING RESTORE\n" );
           return 1;
       }
       doupdate();

       attron(COLOR_PAIR(1));
       print_in_middle(stdscr, LINES / 2 + 9, 0, 0, "Read from /tmp/scr.dump" );
       attroff(COLOR_PAIR(1));
   } else {
       attron(COLOR_PAIR(1));
       print_in_middle(stdscr, LINES / 2, 0, 0, "Viola !!! In color ...");
       attroff(COLOR_PAIR(1));

       if ( scr_dump( "/tmp/scr.dump" )!=OK )
       {
           fprintf( stderr, "ERROR WHILE DUMPING" );
           return 1;
       }
   }

  getch();
   endwin();
}

void print_in_middle(WINDOW *win, int starty, int startx, int width, char *string)
{  int length, x, y;
   float temp;

   if(win == NULL)
       win = stdscr;
   getyx(win, y, x);
   if(startx != 0)
       x = startx;
   if(starty != 0)
       y = starty;
   if(width == 0)
       width = 80;

   length = strlen(string);
   temp = (width - length)/ 2;
   x = startx + (int)temp;
   mvwprintw(win, y, x, "%s", string);
   refresh();
}

Answer 1

See man scr_dump :

   scr_dump, scr_restore, scr_init, scr_set -
       read (write) a curses screen from (to) a file