dbm.c

Altera recommends the following system configuration: * Pentium II 400 with 512-MB system memory (fa

/*
 * Copyright (c) 1985 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this notice are
 * duplicated in all such forms.
 *
 * [additional clause stricken -- see below]
 *
 * The name of the University may not be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE.
 *
 * This notice previously contained the additional clause:
 *
 *   and that any documentation, advertising materials, and other
 *   materials related to such distribution and use acknowledge that
 *   the software was developed by the University of California,
 *   Berkeley.
 *
 * Pursuant to the licensing change made by the Office of Technology
 * Licensing of the University of California, Berkeley on July 22,
 * 1999 and documented in:
 *
 *   ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
 *
 * this clause has been stricken and no longer is applicable to this
 * software.
 */

#ifndef lint
static char sccsid[] = "@(#)dbm.c    5.4 (Berkeley) 5/24/89";
#endif /* not lint */

#include    "dbm.h"

#define    NODB    ((DBM *)0)

static DBM *cur_db = NODB;

static char no_db[] = "dbm: no open database\n";

int
dbminit(char *file)
{
    if (cur_db != NODB)
        dbm_close(cur_db);

    cur_db = dbm_open(file, 2, 0);
    if (cur_db == NODB) {
        cur_db = dbm_open(file, 0, 0);
        if (cur_db == NODB)
            return (-1);
    }
    return (0);
}

long
forder(datum key)
{
    if (cur_db == NODB) {
        printf(no_db);
        return (0L);
    }
    return (dbm_forder(cur_db, key));
}

datum
fetch(datum key)
{
    datum item;

    if (cur_db == NODB) {
        printf(no_db);
        item.dptr = 0;
        return (item);
    }
    return (dbm_fetch(cur_db, key));
}

int
delete(datum key)
{
    if (cur_db == NODB) {
        printf(no_db);
        return (-1);
    }
    if (dbm_rdonly(cur_db))
        return (-1);
    return (dbm_delete(cur_db, key));
}

int
store(datum key, datum dat)
{
    if (cur_db == NODB) {
        printf(no_db);
        return (-1);
    }
    if (dbm_rdonly(cur_db))
        return (-1);

    return (dbm_store(cur_db, key, dat, DBM_REPLACE));
}

datum
firstkey(void)
{
    datum item;

    if (cur_db == NODB) {
        printf(no_db);
        item.dptr = 0;
        return (item);
    }
    return (dbm_firstkey(cur_db));
}

datum
nextkey(datum key)
{
    datum item;

    if (cur_db == NODB) {
        printf(no_db);
        item.dptr = 0;
        return (item);
    }
    return (dbm_nextkey(cur_db, key));
}