#include <ndbm.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>

#define MAX_ITER  128
#define ITEM_SIZE 128

static const char* filename = "repro.db";

static char buffer[2* ITEM_SIZE * MAX_ITER] = { '\0' };

static int writer(void)
{
	int k;
	DBM* db = dbm_open(filename, O_RDWR|O_CREAT, 0660);
	if (db == NULL) {
		perror("dbm_open");
		return 1;
	}

	for (k = 0; k < MAX_ITER; k++) {
		char keybuf[64];

		datum key;
		datum value;

		int r;

		sprintf(keybuf, "%04d", k);
		key.dptr = keybuf;
		key.dsize = strlen(keybuf);

		value.dptr = buffer;
		value.dsize = k * ITEM_SIZE;

		r = dbm_store(db, key, value, DBM_REPLACE);
		if (r == -1) {
			perror("dbm_store");
			return 1;
		}
	}

	dbm_close(db);

	return 0;
}

static int reader(void)
{
	int k;
	DBM* db = dbm_open(filename, O_RDONLY, 0660);
	if (db == NULL) {
		perror("dbm_open");
		return 1;
	}

	datum key;

	key = dbm_firstkey(db);
	while (key.dptr != NULL) {
		fwrite(key.dptr, 1, key.dsize, stdout);
		fputs("\n", stdout);

		key = dbm_nextkey(db);
	}

	dbm_close(db);

	return 0;
}

int main(void)
{
	int r;

	r = writer();
	if (r != 0) return 1;

	r = reader();
	if (r != 0) return 1;

	return 0;
}