Unknown malfunction of ncurses

[Anthony Marshall]

Greetings,
 
 
Whilst trying Example 9. A Simple Color example in the NCURSES-Programming-HOWTO.html, I extended the program slightly, thus:
 
 
/*
 
 * colr_ex.c    color example
 
 *
 
 * $Revision: 1.46 $
 
 */
 
 
#include <ncurses.h>
 
#include <string.h>
 
 
static char *msg[] = {
 
        "Viola !!! In color ...","A slightly longer string here ...",
 
        "Short string ..."
 
};
 
 
int prev_x=40, prev_l=0;
 
 
void print_in_middle(WINDOW *win, int starty, int startx, int width, char *string, int cp);
 
 
int main(int argc, char *argv[])
 
{
 
        char fin[]="Example Completed";
 
        register int x=0;
 
 
        initscr();                      /* Start curses mode            */
 
        noecho();
 
        if(has_colors() == FALSE)
 
        {
 
                endwin();
 
                printf("Your terminal does not support color\n");
 
                exit(1);
 
        }
 
        start_color();                  /* Start color                  */
 
        init_pair(1, COLOR_RED, COLOR_BLACK);
 
        init_pair(2, COLOR_BLUE, COLOR_GREEN);
 
        init_pair(3, COLOR_BLACK, COLOR_WHITE);
 
 
/*      for(;x<4;x++)
 
        {                                                               */
 
                attron(COLOR_PAIR(x+1));
 
                print_in_middle(stdscr, LINES / 2, 0, 0, msg[x], x+1);
 
                attroff(COLOR_PAIR(x+1));
 
                mvwprintw(stdscr, LINES-2, 0, "%d iteration completed.", x+1);
 
                wgetch(stdscr);
 
/*      }                                                               */
 
        mvwprintw(stdscr, LINES-2, (COLS-strlen(fin))-1, "%s", fin);
 
        wrefresh(stdscr);
 
        getch();
 
        endwin();
 
}
 
 
void print_in_middle(WINDOW *win, int starty, int startx, int width, char *string, int cp)
 
{
 
        register int c;
 
        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 = COLS;
 
 
        length = strlen(string);
 
        temp = (width - length)/ 2;
 
        x = startx + (int)temp;
 
        if(length<prev_l)
 
        {
 
                move(y,prev_x);
 
                standend();
 
                for(c=0;c<prev_l;c++) addch(' ');
 
                attron(COLOR_PAIR(cp));
 
        }
 
        mvwprintw(win, y, x, "%s", string);
 
        refresh();
 
        prev_x=x;prev_l=length;
 
}
 
 
As you may notice in the main, I have commented out the for() loop because, uncommented, it seems to generate a segmentation error each time it is compiled in and run, and I cannot seem to work out why.
 
 
Could you please advise me why this is the case and is there a solution?