catch.c

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/*
 *  SIGINT handler
 *  rewritten to use portable standard C routines.
 *  Note that handlers cannot nest!
 *  - WH 20020210
 */

#include <stddef.h>
#include <signal.h>
#include "fortrancall.h"

static int *flagptr=NULL;
void (*prev_handler)(int);


/***********************************************************************
 *
 *   ctrlc_handler: simple handler for receiving SIGINT signal
 *
 ***********************************************************************/
void sigint_handler(int sig)
{
    *flagptr=1;
}

/* **********************************************************************
 *    subroutine catchc
 *
 *       Installs a SIGINT handler that sets flag non-zero
 *
 ***********************************************************************/

void FORTRAN(catchc)(int *flag)
{
    if (flagptr==NULL) {
        flagptr=flag;
        *flagptr=0;
        prev_handler=signal(SIGINT, &sigint_handler);
    }
}

/* **********************************************************************
 *
 * subroutine uncatchc()
 *
 *    Restores default action for handling SIGINT signal
 *
 ********************************************************************** */
void FORTRAN(uncatchc)(int *flag)
{
    if (flagptr==flag) {
        if (flagptr) *flagptr=0; /* test */
        signal(SIGINT, prev_handler);
        flagptr=NULL;
    }
}