1/* seq.c - This is the sequential visit of the database.  This defines two
2   user-visable routines that are used together. This is the DBM interface. */
3
4/*  This file is part of GDBM, the GNU data base manager, by Philip A. Nelson.
5    Copyright (C) 1990, 1991, 1993  Free Software Foundation, Inc.
6
7    GDBM is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2, or (at your option)
10    any later version.
11
12    GDBM is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16
17    You should have received a copy of the GNU General Public License
18    along with GDBM; see the file COPYING.  If not, write to
19    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
20
21    You may contact the author by:
22       e-mail:  phil@cs.wwu.edu
23      us-mail:  Philip A. Nelson
24                Computer Science Department
25                Western Washington University
26                Bellingham, WA 98226
27
28*************************************************************************/
29
30
31/* include system configuration before all else. */
32#include "autoconf.h"
33
34#include "gdbmdefs.h"
35#include "extern.h"
36
37/* Start the visit of all keys in the database.  This produces something in
38   hash order, not in any sorted order.  */
39
40datum
41firstkey ()
42{
43  datum ret_val;
44
45  /* Free previous dynamic memory, do actual call, and save pointer to new
46     memory. */
47  ret_val = gdbm_firstkey (_gdbm_file);
48  if (_gdbm_memory.dptr != NULL) free (_gdbm_memory.dptr);
49  _gdbm_memory = ret_val;
50
51  /* Return the new value. */
52  return ret_val;
53}
54
55
56/* Continue visiting all keys.  The next key following KEY is returned. */
57
58datum
59nextkey (key)
60     datum key;
61{
62  datum ret_val;
63
64  /* Make sure we have a valid key. */
65  if (key.dptr == NULL)
66    return key;
67
68  /* Call gdbm nextkey with supplied value. After that, free the old value. */
69  ret_val = gdbm_nextkey (_gdbm_file, key);
70  if (_gdbm_memory.dptr != NULL) free (_gdbm_memory.dptr);
71  _gdbm_memory = ret_val;
72
73  /* Return the new value. */
74  return ret_val;
75}
76