How do you ignore Quit in csh script?

[Paul Blumstein]

I have a csh script that displays a menu & runs a program with
different options depending on which menu line was selected.
After program termination, the script loops back to the top
and redisplays the menu.

The program is basic a polling program that is terminated
by catching a ^C, cleaning up & terminating.  (It could also
terminate on error conditions).  The program has a debug mode that
is toggled on & off by Quit signals (^\ key).  The program works
fine as a standalone (outside the script).

The problem:
I have "onintr" set in the script to loop the script back to the
beginning when the user hits ^C.  However, when ^\ is hit, the script
core dumps, terminates leaving the program running as a background task.

The man page for csh says "the shell generally ignores Quit signals".
Generally seems to mean interactive shells, not shell scripts.
I ended up re-writing the script as an sh script with a trap.
I prefer csh, though.  Does anyone have any idea how I could have
accomplished this with csh???  Thanks in advance.

Here is a sample script & prog (cut way down):

------------------------ cut here ----------------------
#! /bin/csh -f
onintr start
start:
set choice=""
echo ""
echo "Which version do you wish to run?"
echo "   a. Version 1."
echo "   q. None -- exit this program"
echo ""
echo -n Enter letter:
set choice=($<)
if ($choice == "q") exit
switch ($choice)
case a:
    a.out
    breaksw
default:
    echo Incorrect answer, please try again
    echo ""
    goto start
    breaksw
endsw
goto start
------------------------ cut here ----------------------
#include <stdio.h>
#include <sys/time.h>
#include <string.h>
#include <signal.h>
#include <ctype.h>

#define FALSE 0
#define TRUE  1
#define LOOP_FOREVER    for(;;)
#define DEBUG           if (debugsw) (void) printf
static struct timeval clock;	/* system clock */
static int      debugsw = FALSE;/* debug switch */
int             toggle_debug();	/* turns debug on & off */
int             clean_up();	/* exits gracefully from ^C */

/*************************************************************************/
main()
{
    static struct timeval timeout = {1, 0};
    (void) signal(SIGQUIT, toggle_debug); /* catch ^\ key for debug */
    (void) signal(SIGINT, clean_up);      /* catch ^C key */

    LOOP_FOREVER {
	(void) select(0, (int *) NULL, (int *) NULL, (int *) NULL, &timeout);
    }
}
/*************************************************************************/
toggle_debug()
{
    debugsw = (debugsw ? FALSE : TRUE);	/* toggle the debug state */
    (void) printf("\nD>DEBUG turned %s\n", (debugsw ? "ON" : "OFF"));
}

/***************************************************************/
clean_up()
{
    puts("");
    printf("adios\n");
    exit(0);
}
=============================================================================
Paul Blumstein             | "I before E except after C" is weird.
Citicorp/TTI               |                                 ^^
Santa Monica, CA           +-------------------------------------------------
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