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14. Miscellaneous features

Now you know enough features to write a good curses program, with all bells and whistles. There are some miscellaneous functions which are useful in various cases. Let's go headlong into some of those.

14.1. curs_set()

This function can be used to make the cursor invisible. The parameter to this function should be

    0 : invisible      or
    1 : normal    or
    2 : very visible.

14.2. Temporarily Leaving Curses mode

Some times you may want to get back to cooked mode (normal line buffering mode) temporarily. In such a case you will first need to save the tty modes with a call to def_prog_mode() and then call endwin() to end the curses mode. This will leave you in the original tty mode. To get back to curses once you are done, call reset_prog_mode() . This function returns the tty to the state stored by def_prog_mode(). Then do refresh(), and you are back to the curses mode. Here is an example showing the sequence of things to be done.

Example 12. Temporarily Leaving Curses Mode

#include <ncurses.h>

int main()
{       
        initscr();                      /* Start curses mode              */
        printw("Hello World !!!\n");    /* Print Hello World              */
        refresh();                      /* Print it on to the real screen */
        def_prog_mode();                /* Save the tty modes             */
        endwin();                       /* End curses mode temporarily    */
        system("/bin/sh");              /* Do whatever you like in cooked mode */
        reset_prog_mode();              /* Return to the previous tty mode*/
                                        /* stored by def_prog_mode()      */
        refresh();                      /* Do refresh() to restore the    */
                                        /* Screen contents                */
        printw("Another String\n");     /* Back to curses use the full    */
        refresh();                      /* capabilities of curses         */
        endwin();                       /* End curses mode                */

        return 0;
}

14.3. ACS_ variables

If you have ever programmed in DOS, you know about those nifty characters in extended character set. They are printable only on some terminals. NCURSES functions like box() use these characters. All these variables start with ACS meaning alternative character set. You might have noticed me using these characters in some of the programs above. Here's an example showing all the characters.

Example 13. ACS Variables Example

#include <ncurses.h>

int main()
{
        initscr();

        printw("Upper left corner           "); addch(ACS_ULCORNER); printw("\n"); 
        printw("Lower left corner           "); addch(ACS_LLCORNER); printw("\n");
        printw("Lower right corner          "); addch(ACS_LRCORNER); printw("\n");
        printw("Tee pointing right          "); addch(ACS_LTEE); printw("\n");
        printw("Tee pointing left           "); addch(ACS_RTEE); printw("\n");
        printw("Tee pointing up             "); addch(ACS_BTEE); printw("\n");
        printw("Tee pointing down           "); addch(ACS_TTEE); printw("\n");
        printw("Horizontal line             "); addch(ACS_HLINE); printw("\n");
        printw("Vertical line               "); addch(ACS_VLINE); printw("\n");
        printw("Large Plus or cross over    "); addch(ACS_PLUS); printw("\n");
        printw("Scan Line 1                 "); addch(ACS_S1); printw("\n");
        printw("Scan Line 3                 "); addch(ACS_S3); printw("\n");
        printw("Scan Line 7                 "); addch(ACS_S7); printw("\n");
        printw("Scan Line 9                 "); addch(ACS_S9); printw("\n");
        printw("Diamond                     "); addch(ACS_DIAMOND); printw("\n");
        printw("Checker board (stipple)     "); addch(ACS_CKBOARD); printw("\n");
        printw("Degree Symbol               "); addch(ACS_DEGREE); printw("\n");
        printw("Plus/Minus Symbol           "); addch(ACS_PLMINUS); printw("\n");
        printw("Bullet                      "); addch(ACS_BULLET); printw("\n");
        printw("Arrow Pointing Left         "); addch(ACS_LARROW); printw("\n");
        printw("Arrow Pointing Right        "); addch(ACS_RARROW); printw("\n");
        printw("Arrow Pointing Down         "); addch(ACS_DARROW); printw("\n");
        printw("Arrow Pointing Up           "); addch(ACS_UARROW); printw("\n");
        printw("Board of squares            "); addch(ACS_BOARD); printw("\n");
        printw("Lantern Symbol              "); addch(ACS_LANTERN); printw("\n");
        printw("Solid Square Block          "); addch(ACS_BLOCK); printw("\n");
        printw("Less/Equal sign             "); addch(ACS_LEQUAL); printw("\n");
        printw("Greater/Equal sign          "); addch(ACS_GEQUAL); printw("\n");
        printw("Pi                          "); addch(ACS_PI); printw("\n");
        printw("Not equal                   "); addch(ACS_NEQUAL); printw("\n");
        printw("UK pound sign               "); addch(ACS_STERLING); printw("\n");

        refresh();
        getch();
        endwin();

        return 0;
}