How to break out an infinite loop and then enter another infinite loop?

**superbbrr** · 10-14-2011

I'm trying to create a status menu system with ncurses where the user is presented with three choices along a top row:

H S T

Each option selection prints various status over and over continuously. For ex. If the user chooses H, High status info is constantly being displayed.

If the user then pushes S, the H loop is broken and the S loop enters outputting system status info. And vice versa.

How can I go about this? I was thinking of using GOTO's but I know that's a no-no.

For ex. If I'm in H's while loop, the user pushes S, then that would break H's loop, the user would have to push S again, to enter S's loop.

Ahhhh so confused. (Actually there are more than 3 selections, but for simplicity, I only show 3. This is quickly going to become messy.)

Some pseudo-code below:

Thanks.

Code:

//e or E to exit program
while ((ch = getch()) != 'e' || ch != 'E' )
    {
        if (ch == 'H' || ch == 'h' ) {
            
            //infinite loop to constantly display H's status
            while (1){
                
                getHighStatus function
                print high status

                if S is pressed, break, somehow enter S loop
                if T is pressed, break, somehow enter T loop

            }
        }
        else if (ch == 'S' || ch == 's' ) {
            while (1){
                getSystemStatus function
                print system status
                if H pressed, break, somehow enter H loop
                if T prssed, break, somehow enter T loop
            }
        }
        else if (ch == 'T' || ch == 't' ) {
              while (1){
                getTempStatus function
                print temp status
                if H pressed, break, somehow enter H loop
                if S pressed, break, somehow enter S loop
            }
        }
        else
        {    
            print default message
        }

    }

**quzah** · 10-14-2011

break is indeed what you want. It will break you out of your current loop (or case statement for that matter).

Quzah.

**Salem** · 10-14-2011

A bit of manual page

getch(3NCURSES) getch(3NCURSES)

NAME
getch, wgetch, mvgetch, mvwgetch, ungetch, has_key - get (or push back) characters from curses terminal keyboard

SYNOPSIS
#include <curses.h>

int getch(void);
int wgetch(WINDOW *win);
int mvgetch(int y, int x);
int mvwgetch(WINDOW *win, int y, int x);
int ungetch(int ch);
int has_key(int ch);

DESCRIPTION
The getch, wgetch, mvgetch and mvwgetch, routines read a character from the window. In no-delay mode, if no input is waiting, the value ERR is re‐
turned. In delay mode, the program waits until the system passes text through to the program. Depending on the setting of cbreak, this is after one
character (cbreak mode), or after the first newline (nocbreak mode). In half-delay mode, the program waits until a character is typed or the speci‐
fied timeout has been reached.

So you put ncurses into no-delay mode, and do this.

Code:

while ( 1 ) {
  ch = getch();

  if ( ch == ERR ) ch = lastch; // no key, do same as last time
  ch = tolower(ch);
  lastch = ch;

  if ( ch == 'e' ) break;
  switch ( ch ) {
    case 'h':
      getHighStatus function
      print high status
      break;
    case 's':
      getSystemStatus function
      print system status
      break;
    case 't'
      getTempStatus function
      print temp status
      break;
    // and so on
  }
}

**megafiddle** · 10-14-2011

Couldn't you just do this:

Code:

   //e or E to exit program
   while ((ch = getch()) != 'e' || ch != 'E' )
    {
        if (ch == 'H' || ch == 'h' ) {
                getHighStatus function
                print high status
            }

        else if (ch == 'S' || ch == 's' ) {
                getSystemStatus function
                print system status
             }

        else if (ch == 'T' || ch == 't' ) {
                getTempStatus function
                print temp status
            }

        else
            print default message
    }

edited: oh, yeah, you have to look for change in ch

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