1/* $LP: LPlib/source/LPdir_unix.c,v 1.11 2004/09/23 22:07:22 _cvs_levitte Exp $ */
2/*
3 * Copyright (c) 2004, Richard Levitte <richard@levitte.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <stddef.h>
29#include <stdlib.h>
30#include <limits.h>
31#include <string.h>
32#include <sys/types.h>
33#include <dirent.h>
34#include <errno.h>
35#ifndef LPDIR_H
36#include "LPdir.h"
37#endif
38
39/* The POSIXly macro for the maximum number of characters in a file path
40   is NAME_MAX.  However, some operating systems use PATH_MAX instead.
41   Therefore, it seems natural to first check for PATH_MAX and use that,
42   and if it doesn't exist, use NAME_MAX. */
43#if defined(PATH_MAX)
44# define LP_ENTRY_SIZE PATH_MAX
45#elif defined(NAME_MAX)
46# define LP_ENTRY_SIZE NAME_MAX
47#endif
48
49/* Of course, there's the possibility that neither PATH_MAX nor NAME_MAX
50   exist.  It's also possible that NAME_MAX exists but is define to a
51   very small value (HP-UX offers 14), so we need to check if we got a
52   result, and if it meets a minimum standard, and create or change it
53   if not. */
54#if !defined(LP_ENTRY_SIZE) || LP_ENTRY_SIZE<255
55# undef LP_ENTRY_SIZE
56# define LP_ENTRY_SIZE 255
57#endif
58
59struct LP_dir_context_st
60{
61  DIR *dir;
62  char entry_name[LP_ENTRY_SIZE+1];
63};
64
65const char *LP_find_file(LP_DIR_CTX **ctx, const char *directory)
66{
67  struct dirent *direntry = NULL;
68
69  if (ctx == NULL || directory == NULL)
70    {
71      errno = EINVAL;
72      return 0;
73    }
74
75  errno = 0;
76  if (*ctx == NULL)
77    {
78      *ctx = (LP_DIR_CTX *)malloc(sizeof(LP_DIR_CTX));
79      if (*ctx == NULL)
80	{
81	  errno = ENOMEM;
82	  return 0;
83	}
84      memset(*ctx, '\0', sizeof(LP_DIR_CTX));
85
86      (*ctx)->dir = opendir(directory);
87      if ((*ctx)->dir == NULL)
88	{
89	  int save_errno = errno; /* Probably not needed, but I'm paranoid */
90	  free(*ctx);
91	  *ctx = NULL;
92	  errno = save_errno;
93	  return 0;
94	}
95    }
96
97  direntry = readdir((*ctx)->dir);
98  if (direntry == NULL)
99    {
100      return 0;
101    }
102
103  strncpy((*ctx)->entry_name, direntry->d_name, sizeof((*ctx)->entry_name) - 1);
104  (*ctx)->entry_name[sizeof((*ctx)->entry_name) - 1] = '\0';
105  return (*ctx)->entry_name;
106}
107
108int LP_find_file_end(LP_DIR_CTX **ctx)
109{
110  if (ctx != NULL && *ctx != NULL)
111    {
112      int ret = closedir((*ctx)->dir);
113
114      free(*ctx);
115      switch (ret)
116	{
117	case 0:
118	  return 1;
119	case -1:
120	  return 0;
121	default:
122	  break;
123	}
124    }
125  errno = EINVAL;
126  return 0;
127}
128