#include "config.h"

#if HAVE_GRP_H
#include <grp.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#if HAVE_STRINGS_H
#include <strings.h>
#endif
#if HAVE_LIMITS_H
#include <limits.h>
#endif

int initgroups(const char *name, gid_t basegid)
{
#ifdef HAVE_SETGROUPS
#ifndef NGROUPS_MAX
#define NGROUPS_MAX 16
#endif
    gid_t groups[NGROUPS_MAX];
    struct group *g;
    int index = 0;

    setgrent();

    groups[index++] = basegid;

    while (index < NGROUPS_MAX && ((g = getgrent()) != NULL)) {
	if (g->gr_gid != basegid) {
	    char **names;

	    for (names = g->gr_mem; *names != NULL; ++names) {
		if (!strcmp(*names, name))
		    groups[index++] = g->gr_gid;
	    }
	}
    }

    endgrent();

    return setgroups(index, groups);
#else
    return 0;
#endif /* def HAVE_SETGROUPS */
}