zsh/subreap module

subreap.c

#include<sys/prctl.h>
#include "subreap.mdh"
#include "subreap.pro"

/**/
static int
bin_subreap(char *nam, char **args, Options ops, UNUSED(int func))
{
    int reaping = !OPT_ISSET(ops, 'u');
    int result = prctl(PR_SET_CHILD_SUBREAPER, reaping); 
    return result;
}

/*
 * boot_ is executed when the module is loaded.
 */

static struct builtin bintab[] = {
    BUILTIN("subreap", 0, bin_subreap, 0, -1, 0, "u", NULL),
};

static struct features module_features = {
    bintab, sizeof(bintab)/sizeof(*bintab),
    0
};

/**/
int
setup_(UNUSED(Module m))
{
    return 0;
}

/**/
int
features_(Module m, char ***features)
{
    *features = featuresarray(m, &module_features);
    return 0;
}

/**/
int
enables_(Module m, int **enables)
{
    return handlefeatures(m, &module_features, enables);
}

/**/
int
boot_(Module m)
{
    return 0;
}

/**/
int
cleanup_(Module m)
{
    return setfeatureenables(m, &module_features, NULL);
}

/**/
int
finish_(UNUSED(Module m))
{
    return 0;
}

subreap.mdd

name=zsh/subreap
link=dynamic
load=no

autofeatures="b:subreap"

objects="subreap.o"

Put them in zsh source's Src/Modules directory and then build.