savedir.c revision 56230 
1/* savedir.c -- save the list of files in a directory in a string
2   Copyright (C) 1990, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
3
4   This program is free software; you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 2, or (at your option)
7   any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program; if not, write to the Free Software Foundation,
16   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
17
18/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
19
20#if HAVE_CONFIG_H
21# include <config.h>
22#endif
23
24#include <sys/types.h>
25
26#if HAVE_UNISTD_H
27# include <unistd.h>
28#endif
29
30#if HAVE_DIRENT_H
31# include <dirent.h>
32# define NAMLEN(dirent) strlen((dirent)->d_name)
33#else
34# define dirent direct
35# define NAMLEN(dirent) (dirent)->d_namlen
36# if HAVE_SYS_NDIR_H
37#  include <sys/ndir.h>
38# endif
39# if HAVE_SYS_DIR_H
40#  include <sys/dir.h>
41# endif
42# if HAVE_NDIR_H
43#  include <ndir.h>
44# endif
45#endif
46
47#ifdef CLOSEDIR_VOID
48/* Fake a return value. */
49# define CLOSEDIR(d) (closedir (d), 0)
50#else
51# define CLOSEDIR(d) closedir (d)
52#endif
53
54#ifdef STDC_HEADERS
55# include <stdlib.h>
56# include <string.h>
57#else
58char *malloc ();
59char *realloc ();
60#endif
61#ifndef NULL
62# define NULL 0
63#endif
64
65#ifndef stpcpy
66char *stpcpy ();
67#endif
68
69#include "savedir.h"
70
71/* Return a freshly allocated string containing the filenames
72   in directory DIR, separated by '\0' characters;
73   the end is marked by two '\0' characters in a row.
74   NAME_SIZE is the number of bytes to initially allocate
75   for the string; it will be enlarged as needed.
76   Return NULL if DIR cannot be opened or if out of memory. */
77
78char *
79savedir (dir, name_size)
80     const char *dir;
81     unsigned int name_size;
82{
83  DIR *dirp;
84  struct dirent *dp;
85  char *name_space;
86  char *namep;
87
88  dirp = opendir (dir);
89  if (dirp == NULL)
90    return NULL;
91
92  /* Be sure name_size is at least `1' so there's room for
93     the final NUL byte.  */
94  name_size += !name_size;
95
96  name_space = (char *) malloc (name_size);
97  if (name_space == NULL)
98    {
99      closedir (dirp);
100      return NULL;
101    }
102  namep = name_space;
103
104  while ((dp = readdir (dirp)) != NULL)
105    {
106      /* Skip "." and ".." (some NFS filesystems' directories lack them). */
107      if (dp->d_name[0] != '.'
108	  || (dp->d_name[1] != '\0'
109	      && (dp->d_name[1] != '.' || dp->d_name[2] != '\0')))
110	{
111	  unsigned size_needed = (namep - name_space) + NAMLEN (dp) + 2;
112
113	  if (size_needed > name_size)
114	    {
115	      char *new_name_space;
116
117	      while (size_needed > name_size)
118		name_size += 1024;
119
120	      new_name_space = realloc (name_space, name_size);
121	      if (new_name_space == NULL)
122		{
123		  closedir (dirp);
124		  return NULL;
125		}
126	      namep += new_name_space - name_space;
127	      name_space = new_name_space;
128	    }
129	  namep = stpcpy (namep, dp->d_name) + 1;
130	}
131    }
132  *namep = '\0';
133  if (CLOSEDIR (dirp))
134    {
135      free (name_space);
136      return NULL;
137    }
138  return name_space;
139}
140