#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <grp.h>

int main() {
	int saved_errno;
	for (;;) {
		errno = 0;
		struct group *gr = getgrent();
		saved_errno = errno;
		if (gr) {
			printf("name: %s members: ", gr->gr_name);
		}
		else {
			printf ("End of file or error ");
			break;
		}
		for (char **p = gr->gr_mem; *p; p++) printf ("%s ", *p);
		printf("\n");
	}
	printf("(errno = %s)\n", strerror(saved_errno));
	printf("errno before endgrent() = %s\n", strerror(errno));
	endgrent();
	printf("errno after endgrent() = %s\n", strerror(errno));
}